如何使用共享首选项保存和加载主题？
how do i save and load theme using shared preferences?
请帮帮我，已经 3 天了，我仍然不明白为什么我的共享首选项没有保存或加载我的主题
这是我的主要内容activity
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private static final String SHARED_PREF = "sharedPrefs";
public Button button11, button22, button33;
@Override
protected void onCreate(Bundle savedInstanceState) {
int LT = loadTheme(0);
int ST = saveTheme(0);
Utils.onActivityCreateSetTheme(this, LT,ST);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.button1).setOnClickListener(this);
findViewById(R.id.button2).setOnClickListener(this);
findViewById(R.id.button3).setOnClickListener(this);
}
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
switch (v.getId())
{
case R.id.button1:
Utils.changeToTheme(this, Utils.THEME_DEFAULT);
loadTheme(0);
saveTheme(0);
break;
case R.id.button2:
Utils.changeToTheme(this, Utils.THEME_WHITE);
loadTheme(1);
saveTheme(1);
break;
case R.id.button3:
Utils.changeToTheme(this, Utils.THEME_BLUE);
loadTheme(2);
saveTheme(2);
break;
}
}
public void restartApp() {
Intent i = new Intent(getApplicationContext(),MainActivity.class);
startActivity(i);
finish();
}
public int loadTheme(int defval) {
if (defval == 1) {
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
sharedPreferences.getInt("Theme", 1);
Toast.makeText(this, "LOADTHEMEVAL= 1", Toast.LENGTH_SHORT).show();
} else if (defval == 2) {
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
sharedPreferences.getInt("Theme", 2);
Toast.makeText(this, "LOADTHEMEVAL= 2", Toast.LENGTH_SHORT).show();
} else if(defval == 0) {
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
sharedPreferences.getInt("Theme", 0);
Toast.makeText(this, "LOADTHEMEVAL= 0", Toast.LENGTH_SHORT).show();
}
return defval;
}
public int saveTheme(int defval) {
if (defval == 2) {
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor = sharedPreferences.edit();
prefEditor.clear();
prefEditor.putInt("Theme", 2);
prefEditor.apply();
Toast.makeText(this, "SAVETHEMEVAL= 2", Toast.LENGTH_SHORT).show();
} else if (defval == 1) {
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor = sharedPreferences.edit();
prefEditor.clear();
prefEditor.putInt("Theme", 1);
prefEditor.apply();
Toast.makeText(this, "SAVETHEMEVAL= 1", Toast.LENGTH_SHORT).show();
} else if (defval == 0) {
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor = sharedPreferences.edit();
prefEditor.clear();
prefEditor.putInt("Theme", 0);
prefEditor.apply();
Toast.makeText(this, "SAVETHEMEVAL= 0", Toast.LENGTH_SHORT).show();
}
return defval;
}
}
这是我的工具
package com.perz.themeactivity;
import android.app.Activity;
import android.content.Intent;
public class Utils
{
private static int sTheme;
public final static int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
/**
* Set the theme of the Activity, and restart it by creating a new Activity of the same type.
*/
public static void changeToTheme(Activity activity, int theme)
{
sTheme = theme;
activity.finish();
activity.startActivity(new Intent(activity, activity.getClass()));
}
/** Set the theme of the activity, according to the configuration. */
public static void onActivityCreateSetTheme(Activity activity, int theme, int them)
{
switch (sTheme)
{
default:
case THEME_DEFAULT:
activity.setTheme(R.style.AppTheme);
break;
case THEME_WHITE:
activity.setTheme(R.style.Cerv_Theme);
break;
case THEME_BLUE:
activity.setTheme(R.style.Giant_Theme);
break;
}
}
}
这是我的 activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Theme default"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.101"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.25"
tools:ignore="MissingConstraints" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Cerv_Theme"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.878"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.25"
tools:ignore="MissingConstraints" />
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Giant Theme"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.486"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.366"
tools:ignore="MissingConstraints" />
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="?attr/textcolor"
android:text="PRIMARYLETTER"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.112"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:ignore="MissingConstraints" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="?attr/gaugebackcolor"
android:text="COLOR SECONDARY"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.553"
tools:ignore="MissingConstraints" />
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="?attr/gaugebackcolor"
android:text="COLOR TERTIARY"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.899"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>
和我的color.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="colorPrimary">#E80A0A </color>
<color name="colorPrimaryDark">#E80A0A </color>
<color name="colorPrimaryletter">#E80A0A</color>
<color name="colorSecondary">#000000</color>
<color name="colorTertiary">#E80A0A</color>
<color name="colorAccent">#000000</color>
<color name="pure_black">#000000</color>
</resources>
最后是我的 style.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
<item name="backgroundColor">@color/pure_black</item>
<item name="textcolor">@color/colorPrimaryletter</item>
<item name="gaugebackcolor">@color/colorSecondary</item>
<item name="scalecolor">@color/colorTertiary</item>
<item name="colorback">@color/colorAccent</item>
</style>
<style name="Cerv_Theme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#000000</item>
<item name="colorPrimaryDark">#EFECEC</item>
<item name="colorAccent">#000000</item>
<item name="backgroundColor">#000000</item>
<item name="textcolor">#EFECEC</item>
<item name="gaugebackcolor">#FFFFFF</item>
<item name="scalecolor">#000000</item>
<item name="colorback">#000000</item>
</style>
<style name="Giant_Theme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#0143C6</item>
<item name="colorPrimaryDark">#FFFFFF</item>
<item name="colorAccent">#0439A3</item>
<item name="backgroundColor">#000000</item>
<item name="textcolor">#EFECEC</item>
<item name="gaugebackcolor">#0143C6</item>
<item name="scalecolor">#000000</item>
<item name="colorback">#0439A3</item>
</style>
</resources>
请帮帮我，我真的很想完成这项工作，我已经尝试了几个与我的问题相关的答案，例如： , , Storing an int value using Shared preferences , , How to change the int value onclick and pass it to another activity ? on android? and lastly 但是
他们没有解决我的问题:(
此时 link :
我尝试将答案应用到我的应用程序
现在 UTILS 看起来像这样
package com.perz.themeactivity;
import android.app.Activity;
import android.content.Intent;
public class Utils
{
private static int sTheme;
public final static int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
/**
* Set the theme of the Activity, and restart it by creating a new Activity of the same type.
*/
public static void changeToTheme(Activity activity, int theme)
{
sTheme = theme;
activity.finish();
activity.startActivity(new Intent(activity, activity.getClass()));
}
/** Set the theme of the activity, according to the configuration. */
public static void onActivityCreateSetTheme(Activity activity, int sTheme)
{
switch (sTheme)
{
default:
case THEME_DEFAULT:
int myTheme = R.style.AppTheme;
activity.setTheme(myTheme);
MainActivity obj0 = new MainActivity();
obj0.saveTheme(myTheme);
break;
case THEME_WHITE:
int myTheme1 = R.style.Cerv_Theme;
activity.setTheme(myTheme1);
MainActivity obj1 = new MainActivity();
obj1.saveTheme(myTheme1);
break;
case THEME_BLUE:
int myTheme2 = R.style.Giant_Theme;
activity.setTheme(myTheme2);
MainActivity obj2 = new MainActivity();
obj2.saveTheme(myTheme2);
break;
}
}
}
和主要 ACTIVITY
{
private static final String SHARED_PREF = "sharedPrefs";
private static final int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
public Button button11, button22, button33;
@Override
protected void onCreate(Bundle savedInstanceState) {
int theme = loadTheme();
Utils.onActivityCreateSetTheme(this,theme );
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.button1).setOnClickListener(this);
findViewById(R.id.button2).setOnClickListener(this);
findViewById(R.id.button3).setOnClickListener(this);
}
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
switch (v.getId())
{
case R.id.button1:
Utils.changeToTheme(this, Utils.THEME_DEFAULT);
break;
case R.id.button2:
Utils.changeToTheme(this, Utils.THEME_WHITE);
break;
case R.id.button3:
Utils.changeToTheme(this, Utils.THEME_BLUE);
break;
}
}
public void restartApp() {
Intent i = new Intent(getApplicationContext(),MainActivity.class);
startActivity(i);
finish();
}
public int loadTheme(){
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
//Load theme color
int theme = sharedPreferences.getInt("Theme",THEME_DEFAULT); //RED is default color, when nothing is saved yet
return theme;
}
public void saveTheme(int theme)
{
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
SharedPreferences.Editor prefEditor = sharedPreferences.edit();
prefEditor.putInt("Theme",theme);
}
}
现在调试器输出
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.perz.themeactivity, PID: 23544
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.perz.themeactivity/com.perz.themeactivity.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2778)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
at android.content.ContextWrapper.getPackageName(ContextWrapper.java:135)
at android.preference.PreferenceManager.getDefaultSharedPreferencesName(PreferenceManager.java:537)
at android.preference.PreferenceManager.getDefaultSharedPreferences(PreferenceManager.java:526)
at com.perz.themeactivity.MainActivity.saveTheme(MainActivity.java:66)
at com.perz.themeactivity.Utils.onActivityCreateSetTheme(Utils.java:30)
at com.perz.themeactivity.MainActivity.onCreate(MainActivity.java:23)
at android.app.Activity.performCreate(Activity.java:7009)
at android.app.Activity.performCreate(Activity.java:7000)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2731)
很明显，即使我稍微调整一下，它也无法正常工作，继续。
接下来是：
我使用了最佳答案
现在是 UTILS :
{
private static int sTheme;
public final static int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
/**
* Set the theme of the Activity, and restart it by creating a new Activity of the same type.
*/
public static void changeToTheme(Activity activity, int theme)
{
sTheme = theme;
activity.finish();
activity.startActivity(new Intent(activity, activity.getClass()));
}
/** Set the theme of the activity, according to the configuration. */
public static void onActivityCreateSetTheme(Activity activity, int theme)
{
switch (sTheme)
{
default:
case THEME_DEFAULT:
activity.setTheme(R.style.AppTheme);
break;
case THEME_WHITE:
activity.setTheme(R.style.Cerv_Theme);
break;
case THEME_BLUE:
activity.setTheme(R.style.Giant_Theme);
break;
}
}
}
和主要 ACTIVITY :
{
private static final String SHARED_PREF = "sharedPrefs";
public final static int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
public Button button11, button22, button33;
@Override
protected void onCreate(Bundle savedInstanceState) {
Utils.onActivityCreateSetTheme(this, new SharedPreferencesManager(this).retrieveInt("theme", THEME_DEFAULT));
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.button1).setOnClickListener(this);
findViewById(R.id.button2).setOnClickListener(this);
findViewById(R.id.button3).setOnClickListener(this);
}
@Override
public void onClick(View v)
{
switch (v.getId())
{
case R.id.button1:
Utils.changeToTheme(this, Utils.THEME_DEFAULT);
new SharedPreferencesManager(getApplicationContext()).storeInt("theme", THEME_DEFAULT);
break;
case R.id.button2:
Utils.changeToTheme(this, Utils.THEME_WHITE);
new SharedPreferencesManager(getApplicationContext()).storeInt("theme", THEME_WHITE);
break;
case R.id.button3:
Utils.changeToTheme(this, Utils.THEME_BLUE);
new SharedPreferencesManager(getApplicationContext()).storeInt("theme", THEME_BLUE);
break;
}
}
public void restartApp() {
Intent i = new Intent(getApplicationContext(),MainActivity.class);
startActivity(i);
finish();
}
}
和我的 SHAREDPREFERENCEMANAGER
package com.perz.themeactivity;
import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
public class SharedPreferencesManager {
/**
* SharedPreferences to store the settings. This way, they'll be available next time the user starts the app
*/
private SharedPreferences sPreferences;
/**
* Editor to make changes on sharedPreferences
*/
private SharedPreferences.Editor sEditor;
/**
* The class itself
*/
private Context context;
public SharedPreferencesManager(Context context) {
this.context = context;
sPreferences = PreferenceManager.getDefaultSharedPreferences(context);
}
private SharedPreferences.Editor getEditor() {
return sPreferences.edit();
}
/**
* Store a boolean value in sharedPreferences
*
* @param tag identifies the value
* @param value the value itself
*/
public void storeBoolean(String tag, boolean value) {
sEditor = getEditor();
sEditor.putBoolean(tag, value);
sEditor.commit();
}
/**
* Store a string in sharedPreferences
*
* @param tag identifies the value
* @param str the string itself
*/
public void storeString(String tag, String str) {
sEditor = getEditor();
sEditor.putString(tag, str);
sEditor.commit();
}
/**
* @param tag identifies the value
* @param defValue default value
* @return the stored or default value
*/
public boolean retrieveBoolean(String tag, boolean defValue) {
return sPreferences.getBoolean(tag, defValue);
}
/**
* @param tag identifies the string
* @param defStr default string
* @return the stored or default string
*/
public String retrieveString(String tag, String defStr) {
return sPreferences.getString(tag, defStr);
}
/**
* @param tag identifies the value
* @param defValue default value
* @return the stored or default value
*/
public int retrieveInt(String tag, int defValue) {
return sPreferences.getInt(tag, defValue);
}
/**
* @param tag identifies the value
* @param defValue the value itself
*/
public void storeInt(String tag, int defValue) {
sEditor = getEditor();
sEditor.putInt(tag, defValue);
sEditor.commit();
}
//Incorrect Bracket Closing Removal
}
现在，当我退出应用程序时，它 returns 到默认主题并且它不存储 int
我只想选择即使退出应用程序仍保留的主题 return，如果这看起来有点复杂，我深表歉意
找到答案了！！！首先你需要确保在 UTILS
public static void onActivityCreateSetTheme(Activity activity, int theme)
{
switch (sTheme)
应该是这样的
public static void onActivityCreateSetTheme(Activity activity, int sTheme)
{
switch (sTheme)
它应该始终匹配“开关”部分
你的第二件事activity/mainactivity
而不是使用“保存主题”，
像这样将您的主题直接保存在 onclicklistener 上
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
switch (v.getId())
{
case R.id.button1:
Utils.changeToTheme(this, Utils.THEME_DEFAULT);
defval = 0;
Reptheme += Utils.THEME_DEFAULT;
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor = sharedPreferences.edit();
prefEditor.putInt("Theme", Utils.THEME_DEFAULT);
prefEditor.apply();
value.setText("null" +defval);
Toast.makeText(this, "SAVETHEMEVAL= 0", Toast.LENGTH_SHORT).show();
break;
case R.id.button2:
Utils.changeToTheme(this, Utils.THEME_WHITE);
defval = 1;
Reptheme += Utils.THEME_WHITE;
SharedPreferences sharedPreferences1 = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor1 = sharedPreferences1.edit();
prefEditor1.putInt("Theme", Utils.THEME_WHITE);
prefEditor1.apply();
value.setText("null" +defval);
Toast.makeText(this, "SAVETHEMEVAL= 1", Toast.LENGTH_SHORT).show();
break;
case R.id.button3:
Utils.changeToTheme(this, Utils.THEME_BLUE);
defval = 2;
Reptheme += Utils.THEME_BLUE;
SharedPreferences sharedPreferences2 = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor2 = sharedPreferences2.edit();
prefEditor2.putInt("Theme", Utils.THEME_BLUE);
prefEditor2.apply();
value.setText("null" +defval);
Toast.makeText(this, "SAVETHEMEVAL= 2", Toast.LENGTH_SHORT).show();
break;
}
}
最后像这样使用“加载主题”
public int loadTheme(){
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
int theme = sharedPreferences.getInt("Theme",1);
return theme;
}
总结一下，这是我的主要内容activity
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private static final String SHARED_PREF = "sharedPrefs";
int defval = 1;
int Reptheme ;
public Button button11, button22, button33;
TextView value;
@Override
protected void onCreate(Bundle savedInstanceState) {
Utils.onActivityCreateSetTheme(this, loadTheme());
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.button1).setOnClickListener(this);
findViewById(R.id.button2).setOnClickListener(this);
findViewById(R.id.button3).setOnClickListener(this);
value = (TextView) findViewById(R.id.textView4);
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
defval = sharedPreferences.getInt("Theme", + defval);
value.setText("null" + defval);
}
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
switch (v.getId())
{
case R.id.button1:
Utils.changeToTheme(this, Utils.THEME_DEFAULT);
defval = 0;
Reptheme += Utils.THEME_DEFAULT;
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor = sharedPreferences.edit();
prefEditor.putInt("Theme", Utils.THEME_DEFAULT);
prefEditor.apply();
value.setText("null" +defval);
Toast.makeText(this, "SAVETHEMEVAL= 0", Toast.LENGTH_SHORT).show();
break;
case R.id.button2:
Utils.changeToTheme(this, Utils.THEME_WHITE);
defval = 1;
Reptheme += Utils.THEME_WHITE;
SharedPreferences sharedPreferences1 = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor1 = sharedPreferences1.edit();
prefEditor1.putInt("Theme", Utils.THEME_WHITE);
prefEditor1.apply();
value.setText("null" +defval);
Toast.makeText(this, "SAVETHEMEVAL= 1", Toast.LENGTH_SHORT).show();
break;
case R.id.button3:
Utils.changeToTheme(this, Utils.THEME_BLUE);
defval = 2;
Reptheme += Utils.THEME_BLUE;
SharedPreferences sharedPreferences2 = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor2 = sharedPreferences2.edit();
prefEditor2.putInt("Theme", Utils.THEME_BLUE);
prefEditor2.apply();
value.setText("null" +defval);
Toast.makeText(this, "SAVETHEMEVAL= 2", Toast.LENGTH_SHORT).show();
break;
}
}
public void restartApp() {
Intent i = new Intent(getApplicationContext(),MainActivity.class);
startActivity(i);
finish();
}
public int loadTheme(){
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
//Load theme colorfdsfdssdfsdfsfsd
int theme = sharedPreferences.getInt("Theme",1); //RED is default color, when nothing is saved yet
return theme;
}
}
和我的UTILS.java
import android.app.Activity;
import android.content.Intent;
public class Utils
{
private static int sTheme;
public final static int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
/**
* Set the theme of the Activity, and restart it by creating a new Activity of the same type.
*/
public static void changeToTheme(Activity activity, int theme)
{
sTheme = theme;
activity.finish();
activity.startActivity(new Intent(activity, activity.getClass()));
}
/** Set the theme of the activity, according to the configuration. */
public static void onActivityCreateSetTheme(Activity activity, int sTheme)
{
switch (sTheme)
{
default:
case THEME_DEFAULT:
activity.setTheme(R.style.AppTheme);
break;
case THEME_WHITE:
activity.setTheme(R.style.Cerv_Theme);
break;
case THEME_BLUE:
activity.setTheme(R.style.Giant_Theme);
break;
}
}
}
请帮帮我，已经 3 天了，我仍然不明白为什么我的共享首选项没有保存或加载我的主题
这是我的主要内容activity
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private static final String SHARED_PREF = "sharedPrefs";
public Button button11, button22, button33;
@Override
protected void onCreate(Bundle savedInstanceState) {
int LT = loadTheme(0);
int ST = saveTheme(0);
Utils.onActivityCreateSetTheme(this, LT,ST);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.button1).setOnClickListener(this);
findViewById(R.id.button2).setOnClickListener(this);
findViewById(R.id.button3).setOnClickListener(this);
}
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
switch (v.getId())
{
case R.id.button1:
Utils.changeToTheme(this, Utils.THEME_DEFAULT);
loadTheme(0);
saveTheme(0);
break;
case R.id.button2:
Utils.changeToTheme(this, Utils.THEME_WHITE);
loadTheme(1);
saveTheme(1);
break;
case R.id.button3:
Utils.changeToTheme(this, Utils.THEME_BLUE);
loadTheme(2);
saveTheme(2);
break;
}
}
public void restartApp() {
Intent i = new Intent(getApplicationContext(),MainActivity.class);
startActivity(i);
finish();
}
public int loadTheme(int defval) {
if (defval == 1) {
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
sharedPreferences.getInt("Theme", 1);
Toast.makeText(this, "LOADTHEMEVAL= 1", Toast.LENGTH_SHORT).show();
} else if (defval == 2) {
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
sharedPreferences.getInt("Theme", 2);
Toast.makeText(this, "LOADTHEMEVAL= 2", Toast.LENGTH_SHORT).show();
} else if(defval == 0) {
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
sharedPreferences.getInt("Theme", 0);
Toast.makeText(this, "LOADTHEMEVAL= 0", Toast.LENGTH_SHORT).show();
}
return defval;
}
public int saveTheme(int defval) {
if (defval == 2) {
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor = sharedPreferences.edit();
prefEditor.clear();
prefEditor.putInt("Theme", 2);
prefEditor.apply();
Toast.makeText(this, "SAVETHEMEVAL= 2", Toast.LENGTH_SHORT).show();
} else if (defval == 1) {
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor = sharedPreferences.edit();
prefEditor.clear();
prefEditor.putInt("Theme", 1);
prefEditor.apply();
Toast.makeText(this, "SAVETHEMEVAL= 1", Toast.LENGTH_SHORT).show();
} else if (defval == 0) {
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor = sharedPreferences.edit();
prefEditor.clear();
prefEditor.putInt("Theme", 0);
prefEditor.apply();
Toast.makeText(this, "SAVETHEMEVAL= 0", Toast.LENGTH_SHORT).show();
}
return defval;
}
}
这是我的工具
package com.perz.themeactivity;
import android.app.Activity;
import android.content.Intent;
public class Utils
{
private static int sTheme;
public final static int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
/**
* Set the theme of the Activity, and restart it by creating a new Activity of the same type.
*/
public static void changeToTheme(Activity activity, int theme)
{
sTheme = theme;
activity.finish();
activity.startActivity(new Intent(activity, activity.getClass()));
}
/** Set the theme of the activity, according to the configuration. */
public static void onActivityCreateSetTheme(Activity activity, int theme, int them)
{
switch (sTheme)
{
default:
case THEME_DEFAULT:
activity.setTheme(R.style.AppTheme);
break;
case THEME_WHITE:
activity.setTheme(R.style.Cerv_Theme);
break;
case THEME_BLUE:
activity.setTheme(R.style.Giant_Theme);
break;
}
}
}
这是我的 activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Theme default"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.101"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.25"
tools:ignore="MissingConstraints" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Cerv_Theme"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.878"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.25"
tools:ignore="MissingConstraints" />
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Giant Theme"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.486"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.366"
tools:ignore="MissingConstraints" />
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="?attr/textcolor"
android:text="PRIMARYLETTER"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.112"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:ignore="MissingConstraints" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="?attr/gaugebackcolor"
android:text="COLOR SECONDARY"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.553"
tools:ignore="MissingConstraints" />
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="?attr/gaugebackcolor"
android:text="COLOR TERTIARY"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.899"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>
和我的color.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="colorPrimary">#E80A0A </color>
<color name="colorPrimaryDark">#E80A0A </color>
<color name="colorPrimaryletter">#E80A0A</color>
<color name="colorSecondary">#000000</color>
<color name="colorTertiary">#E80A0A</color>
<color name="colorAccent">#000000</color>
<color name="pure_black">#000000</color>
</resources>
最后是我的 style.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
<item name="backgroundColor">@color/pure_black</item>
<item name="textcolor">@color/colorPrimaryletter</item>
<item name="gaugebackcolor">@color/colorSecondary</item>
<item name="scalecolor">@color/colorTertiary</item>
<item name="colorback">@color/colorAccent</item>
</style>
<style name="Cerv_Theme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#000000</item>
<item name="colorPrimaryDark">#EFECEC</item>
<item name="colorAccent">#000000</item>
<item name="backgroundColor">#000000</item>
<item name="textcolor">#EFECEC</item>
<item name="gaugebackcolor">#FFFFFF</item>
<item name="scalecolor">#000000</item>
<item name="colorback">#000000</item>
</style>
<style name="Giant_Theme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#0143C6</item>
<item name="colorPrimaryDark">#FFFFFF</item>
<item name="colorAccent">#0439A3</item>
<item name="backgroundColor">#000000</item>
<item name="textcolor">#EFECEC</item>
<item name="gaugebackcolor">#0143C6</item>
<item name="scalecolor">#000000</item>
<item name="colorback">#0439A3</item>
</style>
</resources>
请帮帮我，我真的很想完成这项工作，我已经尝试了几个与我的问题相关的答案，例如：
此时 link :
我尝试将答案应用到我的应用程序
现在 UTILS 看起来像这样
package com.perz.themeactivity;
import android.app.Activity;
import android.content.Intent;
public class Utils
{
private static int sTheme;
public final static int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
/**
* Set the theme of the Activity, and restart it by creating a new Activity of the same type.
*/
public static void changeToTheme(Activity activity, int theme)
{
sTheme = theme;
activity.finish();
activity.startActivity(new Intent(activity, activity.getClass()));
}
/** Set the theme of the activity, according to the configuration. */
public static void onActivityCreateSetTheme(Activity activity, int sTheme)
{
switch (sTheme)
{
default:
case THEME_DEFAULT:
int myTheme = R.style.AppTheme;
activity.setTheme(myTheme);
MainActivity obj0 = new MainActivity();
obj0.saveTheme(myTheme);
break;
case THEME_WHITE:
int myTheme1 = R.style.Cerv_Theme;
activity.setTheme(myTheme1);
MainActivity obj1 = new MainActivity();
obj1.saveTheme(myTheme1);
break;
case THEME_BLUE:
int myTheme2 = R.style.Giant_Theme;
activity.setTheme(myTheme2);
MainActivity obj2 = new MainActivity();
obj2.saveTheme(myTheme2);
break;
}
}
}
和主要 ACTIVITY
{
private static final String SHARED_PREF = "sharedPrefs";
private static final int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
public Button button11, button22, button33;
@Override
protected void onCreate(Bundle savedInstanceState) {
int theme = loadTheme();
Utils.onActivityCreateSetTheme(this,theme );
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.button1).setOnClickListener(this);
findViewById(R.id.button2).setOnClickListener(this);
findViewById(R.id.button3).setOnClickListener(this);
}
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
switch (v.getId())
{
case R.id.button1:
Utils.changeToTheme(this, Utils.THEME_DEFAULT);
break;
case R.id.button2:
Utils.changeToTheme(this, Utils.THEME_WHITE);
break;
case R.id.button3:
Utils.changeToTheme(this, Utils.THEME_BLUE);
break;
}
}
public void restartApp() {
Intent i = new Intent(getApplicationContext(),MainActivity.class);
startActivity(i);
finish();
}
public int loadTheme(){
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
//Load theme color
int theme = sharedPreferences.getInt("Theme",THEME_DEFAULT); //RED is default color, when nothing is saved yet
return theme;
}
public void saveTheme(int theme)
{
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
SharedPreferences.Editor prefEditor = sharedPreferences.edit();
prefEditor.putInt("Theme",theme);
}
}
现在调试器输出
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.perz.themeactivity, PID: 23544
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.perz.themeactivity/com.perz.themeactivity.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2778)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
at android.content.ContextWrapper.getPackageName(ContextWrapper.java:135)
at android.preference.PreferenceManager.getDefaultSharedPreferencesName(PreferenceManager.java:537)
at android.preference.PreferenceManager.getDefaultSharedPreferences(PreferenceManager.java:526)
at com.perz.themeactivity.MainActivity.saveTheme(MainActivity.java:66)
at com.perz.themeactivity.Utils.onActivityCreateSetTheme(Utils.java:30)
at com.perz.themeactivity.MainActivity.onCreate(MainActivity.java:23)
at android.app.Activity.performCreate(Activity.java:7009)
at android.app.Activity.performCreate(Activity.java:7000)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2731)
很明显，即使我稍微调整一下，它也无法正常工作，继续。
接下来是：
我使用了最佳答案
现在是 UTILS :
{
private static int sTheme;
public final static int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
/**
* Set the theme of the Activity, and restart it by creating a new Activity of the same type.
*/
public static void changeToTheme(Activity activity, int theme)
{
sTheme = theme;
activity.finish();
activity.startActivity(new Intent(activity, activity.getClass()));
}
/** Set the theme of the activity, according to the configuration. */
public static void onActivityCreateSetTheme(Activity activity, int theme)
{
switch (sTheme)
{
default:
case THEME_DEFAULT:
activity.setTheme(R.style.AppTheme);
break;
case THEME_WHITE:
activity.setTheme(R.style.Cerv_Theme);
break;
case THEME_BLUE:
activity.setTheme(R.style.Giant_Theme);
break;
}
}
}
和主要 ACTIVITY :
{
private static final String SHARED_PREF = "sharedPrefs";
public final static int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
public Button button11, button22, button33;
@Override
protected void onCreate(Bundle savedInstanceState) {
Utils.onActivityCreateSetTheme(this, new SharedPreferencesManager(this).retrieveInt("theme", THEME_DEFAULT));
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.button1).setOnClickListener(this);
findViewById(R.id.button2).setOnClickListener(this);
findViewById(R.id.button3).setOnClickListener(this);
}
@Override
public void onClick(View v)
{
switch (v.getId())
{
case R.id.button1:
Utils.changeToTheme(this, Utils.THEME_DEFAULT);
new SharedPreferencesManager(getApplicationContext()).storeInt("theme", THEME_DEFAULT);
break;
case R.id.button2:
Utils.changeToTheme(this, Utils.THEME_WHITE);
new SharedPreferencesManager(getApplicationContext()).storeInt("theme", THEME_WHITE);
break;
case R.id.button3:
Utils.changeToTheme(this, Utils.THEME_BLUE);
new SharedPreferencesManager(getApplicationContext()).storeInt("theme", THEME_BLUE);
break;
}
}
public void restartApp() {
Intent i = new Intent(getApplicationContext(),MainActivity.class);
startActivity(i);
finish();
}
}
和我的 SHAREDPREFERENCEMANAGER
package com.perz.themeactivity;
import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
public class SharedPreferencesManager {
/**
* SharedPreferences to store the settings. This way, they'll be available next time the user starts the app
*/
private SharedPreferences sPreferences;
/**
* Editor to make changes on sharedPreferences
*/
private SharedPreferences.Editor sEditor;
/**
* The class itself
*/
private Context context;
public SharedPreferencesManager(Context context) {
this.context = context;
sPreferences = PreferenceManager.getDefaultSharedPreferences(context);
}
private SharedPreferences.Editor getEditor() {
return sPreferences.edit();
}
/**
* Store a boolean value in sharedPreferences
*
* @param tag identifies the value
* @param value the value itself
*/
public void storeBoolean(String tag, boolean value) {
sEditor = getEditor();
sEditor.putBoolean(tag, value);
sEditor.commit();
}
/**
* Store a string in sharedPreferences
*
* @param tag identifies the value
* @param str the string itself
*/
public void storeString(String tag, String str) {
sEditor = getEditor();
sEditor.putString(tag, str);
sEditor.commit();
}
/**
* @param tag identifies the value
* @param defValue default value
* @return the stored or default value
*/
public boolean retrieveBoolean(String tag, boolean defValue) {
return sPreferences.getBoolean(tag, defValue);
}
/**
* @param tag identifies the string
* @param defStr default string
* @return the stored or default string
*/
public String retrieveString(String tag, String defStr) {
return sPreferences.getString(tag, defStr);
}
/**
* @param tag identifies the value
* @param defValue default value
* @return the stored or default value
*/
public int retrieveInt(String tag, int defValue) {
return sPreferences.getInt(tag, defValue);
}
/**
* @param tag identifies the value
* @param defValue the value itself
*/
public void storeInt(String tag, int defValue) {
sEditor = getEditor();
sEditor.putInt(tag, defValue);
sEditor.commit();
}
//Incorrect Bracket Closing Removal
}
现在，当我退出应用程序时，它 returns 到默认主题并且它不存储 int 我只想选择即使退出应用程序仍保留的主题 return，如果这看起来有点复杂，我深表歉意
找到答案了！！！首先你需要确保在 UTILS
public static void onActivityCreateSetTheme(Activity activity, int theme)
{
switch (sTheme)
应该是这样的
public static void onActivityCreateSetTheme(Activity activity, int sTheme)
{
switch (sTheme)
它应该始终匹配“开关”部分
你的第二件事activity/mainactivity
而不是使用“保存主题”， 像这样将您的主题直接保存在 onclicklistener 上
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
switch (v.getId())
{
case R.id.button1:
Utils.changeToTheme(this, Utils.THEME_DEFAULT);
defval = 0;
Reptheme += Utils.THEME_DEFAULT;
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor = sharedPreferences.edit();
prefEditor.putInt("Theme", Utils.THEME_DEFAULT);
prefEditor.apply();
value.setText("null" +defval);
Toast.makeText(this, "SAVETHEMEVAL= 0", Toast.LENGTH_SHORT).show();
break;
case R.id.button2:
Utils.changeToTheme(this, Utils.THEME_WHITE);
defval = 1;
Reptheme += Utils.THEME_WHITE;
SharedPreferences sharedPreferences1 = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor1 = sharedPreferences1.edit();
prefEditor1.putInt("Theme", Utils.THEME_WHITE);
prefEditor1.apply();
value.setText("null" +defval);
Toast.makeText(this, "SAVETHEMEVAL= 1", Toast.LENGTH_SHORT).show();
break;
case R.id.button3:
Utils.changeToTheme(this, Utils.THEME_BLUE);
defval = 2;
Reptheme += Utils.THEME_BLUE;
SharedPreferences sharedPreferences2 = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor2 = sharedPreferences2.edit();
prefEditor2.putInt("Theme", Utils.THEME_BLUE);
prefEditor2.apply();
value.setText("null" +defval);
Toast.makeText(this, "SAVETHEMEVAL= 2", Toast.LENGTH_SHORT).show();
break;
}
}
最后像这样使用“加载主题”
public int loadTheme(){
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
int theme = sharedPreferences.getInt("Theme",1);
return theme;
}
总结一下，这是我的主要内容activity
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private static final String SHARED_PREF = "sharedPrefs";
int defval = 1;
int Reptheme ;
public Button button11, button22, button33;
TextView value;
@Override
protected void onCreate(Bundle savedInstanceState) {
Utils.onActivityCreateSetTheme(this, loadTheme());
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.button1).setOnClickListener(this);
findViewById(R.id.button2).setOnClickListener(this);
findViewById(R.id.button3).setOnClickListener(this);
value = (TextView) findViewById(R.id.textView4);
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
defval = sharedPreferences.getInt("Theme", + defval);
value.setText("null" + defval);
}
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
switch (v.getId())
{
case R.id.button1:
Utils.changeToTheme(this, Utils.THEME_DEFAULT);
defval = 0;
Reptheme += Utils.THEME_DEFAULT;
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor = sharedPreferences.edit();
prefEditor.putInt("Theme", Utils.THEME_DEFAULT);
prefEditor.apply();
value.setText("null" +defval);
Toast.makeText(this, "SAVETHEMEVAL= 0", Toast.LENGTH_SHORT).show();
break;
case R.id.button2:
Utils.changeToTheme(this, Utils.THEME_WHITE);
defval = 1;
Reptheme += Utils.THEME_WHITE;
SharedPreferences sharedPreferences1 = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor1 = sharedPreferences1.edit();
prefEditor1.putInt("Theme", Utils.THEME_WHITE);
prefEditor1.apply();
value.setText("null" +defval);
Toast.makeText(this, "SAVETHEMEVAL= 1", Toast.LENGTH_SHORT).show();
break;
case R.id.button3:
Utils.changeToTheme(this, Utils.THEME_BLUE);
defval = 2;
Reptheme += Utils.THEME_BLUE;
SharedPreferences sharedPreferences2 = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
SharedPreferences.Editor prefEditor2 = sharedPreferences2.edit();
prefEditor2.putInt("Theme", Utils.THEME_BLUE);
prefEditor2.apply();
value.setText("null" +defval);
Toast.makeText(this, "SAVETHEMEVAL= 2", Toast.LENGTH_SHORT).show();
break;
}
}
public void restartApp() {
Intent i = new Intent(getApplicationContext(),MainActivity.class);
startActivity(i);
finish();
}
public int loadTheme(){
SharedPreferences sharedPreferences = getSharedPreferences(SHARED_PREF, MODE_PRIVATE);
//Load theme colorfdsfdssdfsdfsfsd
int theme = sharedPreferences.getInt("Theme",1); //RED is default color, when nothing is saved yet
return theme;
}
}
和我的UTILS.java
import android.app.Activity;
import android.content.Intent;
public class Utils
{
private static int sTheme;
public final static int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
/**
* Set the theme of the Activity, and restart it by creating a new Activity of the same type.
*/
public static void changeToTheme(Activity activity, int theme)
{
sTheme = theme;
activity.finish();
activity.startActivity(new Intent(activity, activity.getClass()));
}
/** Set the theme of the activity, according to the configuration. */
public static void onActivityCreateSetTheme(Activity activity, int sTheme)
{
switch (sTheme)
{
default:
case THEME_DEFAULT:
activity.setTheme(R.style.AppTheme);
break;
case THEME_WHITE:
activity.setTheme(R.style.Cerv_Theme);
break;
case THEME_BLUE:
activity.setTheme(R.style.Giant_Theme);
break;
}
}
}