java - 从 xml 运行另一个 Activity

Question

基本上，我只是尝试从另一个 Activity 类运行一个名为NotificationReceiverActivity 的类，但是当我单击按钮运行该 Activity 类时，屏幕上没有显示任何内容，我觉得我完全是一个noob 代码的 xml 部分，这里是 AndroidManifest.xml ；

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="de.vogella.android.notificationmanager"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="16"
    android:targetSdkVersion="18" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="de.vogella.android.notificationmanager.CreateNotificationActivity"
        android:configChanges="orientation|keyboardHidden|screenSize"
        android:label="@string/app_name"
        android:theme="@style/FullscreenTheme" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name="de.vogella.android.notificationmanager.NotificationReceiverActivity"
        android:label="@string/app_name" 
        android:screenOrientation="portrait">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>


</application>

主要 Activity 是 CreateNotificationActivity 类，可以完美地工作和打开。

主要 Activity 的 Java 代码；

public class CreateNotificationActivity extends Activity {
 @Override
 public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}

public void createNotification(View view) {
// Prepare intent which is triggered if the
// notification is selected
Intent intent = new Intent(this, NotificationReceiverActivity.class);
PendingIntent pIntent = PendingIntent.getActivity(this, 0, intent, 0);

// Build notification
// Actions are just fake
Notification noti = new Notification.Builder(this)
    .setContentTitle("New mail from " + "test@gmail.com")
    .setContentText("Subject").setSmallIcon(R.drawable.icon)
    .setContentIntent(pIntent)

    .addAction(R.drawable.ic_launcher, "Call", pIntent)
    .addAction(R.drawable.ic_launcher, "More", pIntent)
    .addAction(R.drawable.ic_launcher, "And more", pIntent).build();
NotificationManager notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
// hide the notification after its selected
noti.flags |= Notification.FLAG_ONGOING_EVENT;

notificationManager.notify(0, noti);

}
}

以及NotificationReceiverActivity类；

   public class NotificationReceiverActivity extends Activity implements OnClickListener {
    private final String CLASSNAME = getClass().getSimpleName();

   Camera cam = null;
   ImageButton ib1;
   Parameters para;
   PowerManager pm;
   WakeLock wl;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
       requestWindowFeature(Window.FEATURE_NO_TITLE);
       getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN);
       pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
       wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK, "whatever");
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);

       wl.acquire();
       initialize();
      ib1.setOnClickListener(this);
       Log.i(CLASSNAME, "CREATING NOW"+cam);
   }

   private void initialize() {
       // TODO Auto-generated method stub
       ib1 = (ImageButton) findViewById(R.id.ib2);
   }

   public void onClick(View v) {
// TODO Auto-generated method stub
if (cam == null) {
    cam = Camera.open();
    para = cam.getParameters();
    para.setFlashMode(Parameters.FLASH_MODE_TORCH);
    cam.setParameters(para);
    Log.i(CLASSNAME, "AA"+cam);

} else {
    para.setFlashMode(Parameters.FLASH_MODE_OFF);
    cam.setParameters(para);
    cam.release();
    cam = null;
    Log.i(CLASSNAME, "BB"+cam);

}
   }

   @Override
   protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
wl.release();
cam=cam;
finish();
   }
@Override
 protected void onDestroy() {
super.onDestroy();
    cam=cam;

 }


}

以及log cat的前4行；

01-31 06:11:10.582: E/AndroidRuntime(29533): FATAL EXCEPTION: main
01-31 06:11:10.582: E/AndroidRuntime(29533): java.lang.RuntimeException: Unable to start activity ComponentInfo{de.vogella.android.notificationmanager/de.vogella.android.notificationmanager.NotificationReceiverActivity}: java.lang.SecurityException: Neither user 10181 nor current process has android.permission.WAKE_LOCK.
01-31 06:11:10.582: E/AndroidRuntime(29533):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2110)
01-31 06:11:10.582: E/AndroidRuntime(29533):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)

Answer 1

从您的NotificationReceiverActivity中删除 Intent 过滤器。

要使用按钮从 CreateNotificationActivity 启动NotificationReceiverActivity，您必须为 Activity 中的该按钮分配一个点击监听器

这是一个例子

public class CreateNotificationActivity extends Activity {

Button button;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    addListenerOnButton();

}

public void addListenerOnButton() {

    button = (Button) findViewById(R.id.button1);

    button.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {

         Intent intent = new Intent(CreateNotificationActivity.this,NotificationReceiverActivity.class);
         startActivity(intent);


        }

    });

}

}