以编程方式更改 Activity 主题不起作用

Question

我想通过代码更改应用主题，但它不起作用。

   @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setTheme(R.style.NightMode);

    setContentView(R.layout.activity_main);

    Toolbar toolbar = findViewById(R.id.toolbar);
    setSupportActionBar(toolbar)

错误

E/AndroidRuntime: FATAL EXCEPTION: main Process: com.w7orld.animex, PID: 23421 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.w7orld.animex/com.w7orld.animex.MainActivity}: java.lang.IllegalStateException: This Activity already has an action bar supplied by the window decor. Do not request Window.FEATURE_SUPPORT_ACTION_BAR and set windowActionBar to false in your theme to use a Toolbar instead. 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.IllegalStateException: This Activity already has an action bar supplied by the window decor. Do not request Window.FEATURE_SUPPORT_ACTION_BAR and set windowActionBar to false in your theme to use a Toolbar instead. at android.support.v7.app.AppCompatDelegateImpl.setSupportActionBar(AppCompatDelegateImpl.java:345) at android.support.v7.app.AppCompatActivity.setSupportActionBar(AppCompatActivity.java:130) at com.w7orld.animex.MainActivity.onCreate(MainActivity.java:70) 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) 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)

Answer 1

第一个可见的问题是这些行的位置：

setTheme(R.style.NightMode);

setContentView(R.layout.activity_main);

您必须始终在 super.onCreate(savedInstanceState); 之后立即调用 setContentView(layout)。因为这是生成布局及其视图的代码。

Answer 2

我们这样设置夜间模式：

public class App extends Application {
 public static final String TAG = "App";

private boolean isNightModeEnabled = false;

 @Override
   public void onCreate() {
   super.onCreate();

  // We load the Night Mode state here
   SharedPreferences mPrefs =  PreferenceManager.getDefaultSharedPreferences(this);
   this.isNightModeEnabled = mPrefs.getBoolean(“NIGHT_MODE”, false);
 }

public boolean isNightModeEnabled() {
   return isNightModeEnabled;
 }

public void setIsNightModeEnabled(boolean isNightModeEnabled) {
   this.isNightModeEnabled = isNightModeEnabled;
  }
}

由于此实例将在其他所有实例之前启动，因此您可以随时调用 isNightModeEnabled()，因此，一旦您的应用程序打开，任何 Activity。

public final class FeedActivity extends AppCompatActivity {
 private final static String TAG = “FeedActivity”;

@Override
 protected void onCreate(Bundle savedInstanceState) {
    if (MyApplication.getInstance().isNightModeEnabled()) {
       setTheme(R.style.FeedActivityThemeDark);
    }
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_feed);
 }
}

How to work with night-mode in Android is posted here

下面是一些示例图片，显示了在灯光模式和夜间模式之间骑行的区别：

Answer 3

我找到了这样做的方法。在 onCreate 我把这个

setTheme(Designs.getThemeNoActionBar(this));
    setContentView(R.layout.activity_main);

从共享首选项获取主题和 return 没有操作栏的主题。

  public static int getThemeNoActionBar(Context context) {
        SharedPreferences sharedPreferences = context.getSharedPreferences("Designs", Context.MODE_PRIVATE);
        int theme = sharedPreferences.getInt("theme", R.style.AppTheme);
        if (theme == nightModeTheme)
            return R.style.NightMode_NoActionBar;
        else if (theme == theme1)
            return R.style.Theme1_NoActionBar;
        else 
             return R.style.AppTheme_NoActionBar;
    }

样式res

<style name="AppTheme.NoActionBar">
    <item name="windowActionBar">false</item>
    <item name="windowNoTitle">true</item>
</style>

<style name="NightMode.NoActionBar">
    <item name="windowActionBar">false</item>
    <item name="windowNoTitle">true</item>
</style>

<style name="Theme1.NoActionBar">
    <item name="windowActionBar">false</item>
    <item name="windowNoTitle">true</item>
</style>

以编程方式更改 Activity 主题不起作用

Change Activity theme programmatically dosen't work

android

runtimeexception

android-theme

android-activity