按钮和导航项的相同操作
Same action for button and an nav item
我有 3 个项目和 3 个按钮。对于按钮，我创建了一个号召性用语功能，并且该意图运行良好。我想将相同的操作添加到我的导航项中。我该怎么做？
说的很清楚。单击按钮和导航项时，我需要显示相同的 activity。我是 Android 的新手。所以我什至不知道这是否可能。或者我正在使用正确的方法来做到这一点。
这些是我用于按钮的意图：
public void exploreActivity(View view){
Intent intent = new Intent(this,ExploreActivity.class);
startActivity(intent);
}
public void packagesActivity(View view){
Intent intent = new Intent(this,PackagesActivity.class);
startActivity(intent);
}
public void dealsActivity(View view){
Intent intent = new Intent(this,DealsActivity.class);
startActivity(intent);
}
这些是我的菜单项
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="@id/explore"
android:icon="@drawable/ic_menu_exp"
android:title="@string/Explore" />
<item
android:id="@id/menuPack"
android:icon="@drawable/ic_menu_pack"
android:title="@string/packages" />
<item android:id="@id/dealsMenu"
android:icon="@drawable/ic_menu_deals"
android:title="@string/deals" />
</menu>
这是我现在拥有的三个按钮
<Button
android:id="@+id/explore"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_marginStart="16dp"
android:layout_marginLeft="16dp"
android:layout_marginTop="40dp"
android:background="@null"
android:drawableTop="@drawable/explorebutton"
android:onClick="exploreActivity"
android:text="@string/Explore"
android:textAllCaps="false"
android:textColor="#838383"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toBottomOf="@+id/homelogo" />
<Button
android:id="@+id/packages"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_marginEnd="24dp"
android:layout_marginStart="24dp"
android:layout_marginTop="40dp"
android:background="@null"
android:drawableTop="@drawable/packagebutton"
android:onClick="packagesActivity"
android:text="@string/packages"
android:textAllCaps="false"
android:textColor="#838383"
app:layout_constraintEnd_toStartOf="@+id/deals"
app:layout_constraintStart_toEndOf="@+id/explore"
app:layout_constraintTop_toBottomOf="@+id/homelogo" />
<Button
android:id="@+id/deals"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_marginEnd="16dp"
android:layout_marginRight="16dp"
android:layout_marginTop="40dp"
android:background="@null"
android:drawableTop="@drawable/dealsbutton"
android:onClick="dealsActivity"
android:text="@string/deals"
android:textAllCaps="false"
android:textColor="#838383"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="@+id/homelogo" />
我已经对 HomeActivity.Java
进行了更改
package com.example.windows81.travelspoc;
import android.content.Context;
import android.content.Intent;
import android.support.design.widget.NavigationView;
import android.support.v4.content.ContextCompat;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import java.util.Timer;
import java.util.TimerTask;
public class HomeActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener{
ViewPager viewPager;
LinearLayout sliderDotspanel;
NavigationView mNavigationView;
private int dotscount;
private ImageView[] dots;
private DrawerLayout mDrawerLayout;
private ActionBarDrawerToggle mtoggle;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);
mtoggle = new ActionBarDrawerToggle(this, mDrawerLayout, R.string.open, R.string.close);
mNavigationView.setNavigationItemSelectedListener(this);
mDrawerLayout.addDrawerListener(mtoggle);
mtoggle.syncState();
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
viewPager = (ViewPager) findViewById(R.id.viewPager);
sliderDotspanel = (LinearLayout) findViewById(R.id.SliderDots);
ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(this);
viewPager.setAdapter(viewPagerAdapter);
Timer timer = new Timer();
timer.scheduleAtFixedRate(new MyTimerTask(), 2000, 4000);
dotscount = viewPagerAdapter.getCount();
dots = new ImageView[dotscount];
for (int i = 0; i < dotscount; i++){
dots[i] = new ImageView(this);
dots[i].setImageDrawable(ContextCompat.getDrawable(getApplicationContext(),R.drawable.incative_dot));
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
params.setMargins(8, 0, 8,0);
sliderDotspanel.addView(dots[i], params);
}
dots[0].setImageDrawable(ContextCompat.getDrawable(getApplicationContext(), R.drawable.ic_active));
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
for (int i = 0; i < dotscount; i++){
dots[i].setImageDrawable(ContextCompat.getDrawable(getApplicationContext(), R.drawable.incative_dot));
}
dots[position].setImageDrawable(ContextCompat.getDrawable(getApplicationContext(), R.drawable.ic_active));
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if(mtoggle.onOptionsItemSelected(item)){
return true;
}
return super.onOptionsItemSelected(item);
}
public class MyTimerTask extends TimerTask{
@Override
public void run() {
HomeActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
if (viewPager.getCurrentItem() == 0){
viewPager.setCurrentItem(1);
}else if (viewPager.getCurrentItem() == 1){
viewPager.setCurrentItem(2);
}else{
viewPager.setCurrentItem(0);
}
}
});
}
}
public void myMethod(){
Intent intent = new Intent(this,ExploreActivity.class);
startActivity(intent);
}
public void exploreActivity(View view){
myMethod();
}
public void packagesActivity(View view){
Intent intent = new Intent(this,PackagesActivity.class);
startActivity(intent);
}
public void dealsActivity(View view){
Intent intent = new Intent(this,DealsActivity.class);
startActivity(intent);
}
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.explore) {
Log.d("Explore","Clicked");
myMethod();
}
return false;
}
}
但是我得到以下错误
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.windows81.travelspoc, PID: 3485
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.windows81.travelspoc/com.example.windows81.travelspoc.HomeActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.design.widget.NavigationView.setNavigationItemSelectedListener(android.support.design.widget.NavigationView$OnNavigationItemSelectedListener)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2625)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2691)
at android.app.ActivityThread.access00(ActivityThread.java:188)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1526)
at android.os.Handler.dispatchMessage(Handler.java:111)
at android.os.Looper.loop(Looper.java:207)
at android.app.ActivityThread.main(ActivityThread.java:5790)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1015)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:876)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.design.widget.NavigationView.setNavigationItemSelectedListener(android.support.design.widget.NavigationView$OnNavigationItemSelectedListener)' on a null object reference
at com.example.windows81.travelspoc.HomeActivity.onCreate(HomeActivity.java:40)
at android.app.Activity.performCreate(Activity.java:6275)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2578)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2691)
at android.app.ActivityThread.access00(ActivityThread.java:188)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1526)
at android.os.Handler.dispatchMessage(Handler.java:111)
at android.os.Looper.loop(Looper.java:207)
at android.app.ActivityThread.main(ActivityThread.java:5790)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1015)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:876)
试试这个
像这样创建方法
public void myMethod(){
Intent intent = new Intent(this,ExploreActivity.class);
startActivity(intent);
}
而不是在 Button like this
中调用您的方法
public void exploreActivity(View view){
myMethod()
}
现在在您的 Activity:
中实施 NavigationView.OnNavigationItemSelectedListener 侦听器
public class YourActivity extends AppCompatActivity implements
NavigationView.OnNavigationItemSelectedListene
比集
NavigationView mNavigationView = (NavigationView) findViewById(R.id.account_navigation_view);
`mNavigationView.setNavigationItemSelectedListener(this);`
覆盖方法
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.explore) {
Log.d("Explore","Clicked");
myMethod()
}
}
对于导航菜单 -> 使用 NavigationView 创建它
这里是正确的例子 link -> http://v4all123.blogspot.in/2016/02/navigationview-example-in-android.html
使用此方法，您可以从菜单选项创建导航菜单。
另一种方法是使用 Recyclerview -> 制作 Recyclerview 并通过适配器处理您的所有意图。（如果您有动态列表或长列表，那么我建议使用第二种方法。）
我有 3 个项目和 3 个按钮。对于按钮，我创建了一个号召性用语功能，并且该意图运行良好。我想将相同的操作添加到我的导航项中。我该怎么做？
说的很清楚。单击按钮和导航项时，我需要显示相同的 activity。我是 Android 的新手。所以我什至不知道这是否可能。或者我正在使用正确的方法来做到这一点。
这些是我用于按钮的意图：
public void exploreActivity(View view){
Intent intent = new Intent(this,ExploreActivity.class);
startActivity(intent);
}
public void packagesActivity(View view){
Intent intent = new Intent(this,PackagesActivity.class);
startActivity(intent);
}
public void dealsActivity(View view){
Intent intent = new Intent(this,DealsActivity.class);
startActivity(intent);
}
这些是我的菜单项
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="@id/explore"
android:icon="@drawable/ic_menu_exp"
android:title="@string/Explore" />
<item
android:id="@id/menuPack"
android:icon="@drawable/ic_menu_pack"
android:title="@string/packages" />
<item android:id="@id/dealsMenu"
android:icon="@drawable/ic_menu_deals"
android:title="@string/deals" />
</menu>
这是我现在拥有的三个按钮
<Button
android:id="@+id/explore"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_marginStart="16dp"
android:layout_marginLeft="16dp"
android:layout_marginTop="40dp"
android:background="@null"
android:drawableTop="@drawable/explorebutton"
android:onClick="exploreActivity"
android:text="@string/Explore"
android:textAllCaps="false"
android:textColor="#838383"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toBottomOf="@+id/homelogo" />
<Button
android:id="@+id/packages"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_marginEnd="24dp"
android:layout_marginStart="24dp"
android:layout_marginTop="40dp"
android:background="@null"
android:drawableTop="@drawable/packagebutton"
android:onClick="packagesActivity"
android:text="@string/packages"
android:textAllCaps="false"
android:textColor="#838383"
app:layout_constraintEnd_toStartOf="@+id/deals"
app:layout_constraintStart_toEndOf="@+id/explore"
app:layout_constraintTop_toBottomOf="@+id/homelogo" />
<Button
android:id="@+id/deals"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_marginEnd="16dp"
android:layout_marginRight="16dp"
android:layout_marginTop="40dp"
android:background="@null"
android:drawableTop="@drawable/dealsbutton"
android:onClick="dealsActivity"
android:text="@string/deals"
android:textAllCaps="false"
android:textColor="#838383"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="@+id/homelogo" />
我已经对 HomeActivity.Java
进行了更改package com.example.windows81.travelspoc;
import android.content.Context;
import android.content.Intent;
import android.support.design.widget.NavigationView;
import android.support.v4.content.ContextCompat;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.MenuItem;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import java.util.Timer;
import java.util.TimerTask;
public class HomeActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener{
ViewPager viewPager;
LinearLayout sliderDotspanel;
NavigationView mNavigationView;
private int dotscount;
private ImageView[] dots;
private DrawerLayout mDrawerLayout;
private ActionBarDrawerToggle mtoggle;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);
mtoggle = new ActionBarDrawerToggle(this, mDrawerLayout, R.string.open, R.string.close);
mNavigationView.setNavigationItemSelectedListener(this);
mDrawerLayout.addDrawerListener(mtoggle);
mtoggle.syncState();
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
viewPager = (ViewPager) findViewById(R.id.viewPager);
sliderDotspanel = (LinearLayout) findViewById(R.id.SliderDots);
ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(this);
viewPager.setAdapter(viewPagerAdapter);
Timer timer = new Timer();
timer.scheduleAtFixedRate(new MyTimerTask(), 2000, 4000);
dotscount = viewPagerAdapter.getCount();
dots = new ImageView[dotscount];
for (int i = 0; i < dotscount; i++){
dots[i] = new ImageView(this);
dots[i].setImageDrawable(ContextCompat.getDrawable(getApplicationContext(),R.drawable.incative_dot));
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
params.setMargins(8, 0, 8,0);
sliderDotspanel.addView(dots[i], params);
}
dots[0].setImageDrawable(ContextCompat.getDrawable(getApplicationContext(), R.drawable.ic_active));
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
for (int i = 0; i < dotscount; i++){
dots[i].setImageDrawable(ContextCompat.getDrawable(getApplicationContext(), R.drawable.incative_dot));
}
dots[position].setImageDrawable(ContextCompat.getDrawable(getApplicationContext(), R.drawable.ic_active));
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if(mtoggle.onOptionsItemSelected(item)){
return true;
}
return super.onOptionsItemSelected(item);
}
public class MyTimerTask extends TimerTask{
@Override
public void run() {
HomeActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
if (viewPager.getCurrentItem() == 0){
viewPager.setCurrentItem(1);
}else if (viewPager.getCurrentItem() == 1){
viewPager.setCurrentItem(2);
}else{
viewPager.setCurrentItem(0);
}
}
});
}
}
public void myMethod(){
Intent intent = new Intent(this,ExploreActivity.class);
startActivity(intent);
}
public void exploreActivity(View view){
myMethod();
}
public void packagesActivity(View view){
Intent intent = new Intent(this,PackagesActivity.class);
startActivity(intent);
}
public void dealsActivity(View view){
Intent intent = new Intent(this,DealsActivity.class);
startActivity(intent);
}
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.explore) {
Log.d("Explore","Clicked");
myMethod();
}
return false;
}
}
但是我得到以下错误
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.windows81.travelspoc, PID: 3485
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.windows81.travelspoc/com.example.windows81.travelspoc.HomeActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.design.widget.NavigationView.setNavigationItemSelectedListener(android.support.design.widget.NavigationView$OnNavigationItemSelectedListener)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2625)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2691)
at android.app.ActivityThread.access00(ActivityThread.java:188)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1526)
at android.os.Handler.dispatchMessage(Handler.java:111)
at android.os.Looper.loop(Looper.java:207)
at android.app.ActivityThread.main(ActivityThread.java:5790)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1015)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:876)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.design.widget.NavigationView.setNavigationItemSelectedListener(android.support.design.widget.NavigationView$OnNavigationItemSelectedListener)' on a null object reference
at com.example.windows81.travelspoc.HomeActivity.onCreate(HomeActivity.java:40)
at android.app.Activity.performCreate(Activity.java:6275)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2578)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2691)
at android.app.ActivityThread.access00(ActivityThread.java:188)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1526)
at android.os.Handler.dispatchMessage(Handler.java:111)
at android.os.Looper.loop(Looper.java:207)
at android.app.ActivityThread.main(ActivityThread.java:5790)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1015)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:876)
试试这个
像这样创建方法
public void myMethod(){
Intent intent = new Intent(this,ExploreActivity.class);
startActivity(intent);
}
而不是在 Button like this
public void exploreActivity(View view){
myMethod()
}
现在在您的 Activity:
中实施NavigationView.OnNavigationItemSelectedListener 侦听器
public class YourActivity extends AppCompatActivity implements
NavigationView.OnNavigationItemSelectedListene
比集
NavigationView mNavigationView = (NavigationView) findViewById(R.id.account_navigation_view);
`mNavigationView.setNavigationItemSelectedListener(this);`
覆盖方法
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.explore) {
Log.d("Explore","Clicked");
myMethod()
}
}
对于导航菜单 -> 使用 NavigationView 创建它
这里是正确的例子 link -> http://v4all123.blogspot.in/2016/02/navigationview-example-in-android.html
使用此方法，您可以从菜单选项创建导航菜单。
另一种方法是使用 Recyclerview -> 制作 Recyclerview 并通过适配器处理您的所有意图。（如果您有动态列表或长列表，那么我建议使用第二种方法。）