Question

我想从通知中触发广播接收器。当我点击通知上的按钮时，它会显示以下错误：

“无法实例化接收器com.example.testservice.myBroad： java.lang.ClassCastException：com.example.testservice.myBroad不能被强制转换为android.content.BroadcastReceiver“

**更新/编辑及其现在工作** 1）嘿伙计们，请帮助处理从通知到广播接收器的2个按钮如何将通知广播触发器中的额外值传递给接收器，无论其播放按钮是按下还是暂停？ 2）现在我的按钮工作，但当我点击通知文本时，它不会让我进入我的活动。任何帮助

我为2个具有额外意图的按钮编写此代码

 RemoteViews layout = new RemoteViews(getPackageName(), R.layout.notification);
            layout.setTextViewText(R.id.notification_title, getString(R.string.app_name));
            Intent clickIntent = new Intent();
            clickIntent.putExtra("button","pause");
            clickIntent.setAction(ACTION_DIALOG);

            PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), pendingRequestCode, clickIntent, pendingFlag);
            layout.setOnClickPendingIntent(R.id.notification_button,pendingIntent);
            builder.setContent(layout);


             layout = new RemoteViews(getPackageName(), R.layout.notification);
            layout.setTextViewText(R.id.notification_title, getString(R.string.app_name));
            Intent click = new Intent();
            clickIntent.putExtra("Button","play");
            clickIntent.setAction(ACTION_DIALOG);

            PendingIntent pi1 = PendingIntent.getBroadcast(getApplicationContext(), pendingRequestCode, click, pendingFlag);
            layout.setOnClickPendingIntent(R.id.notification_button1,pi1);
            builder.setContent(layout);

myBroad接收器文件

Bundle extrasBundle = intent.getExtras();
    String str = (String) extrasBundle.get("button");       
    Toast.makeText(context, str, Toast.LENGTH_SHORT).show();

    context.stopService(new Intent(context, myPlayService.class));

这是我的代码：

void showNotification() {
     int pendingRequestCode = 0;
        int pendingFlag = 0;

        final Resources res = getResources();
        final NotificationManager notificationManager = (NotificationManager) getSystemService(
                NOTIFICATION_SERVICE);
        Intent intent = new Intent(MainActivity.this,myBroad.class);
        PendingIntent pi= PendingIntent.getActivity(this, 0, intent, 0);
        Notification.Builder builder = new Notification.Builder(this)
                .setSmallIcon(R.drawable.ic_action_search)
                .setAutoCancel(true)
                .setTicker("this is notification")
                .setContentIntent(getDialogPendingIntent("Tapped the notification entry."));


            // Sets a custom content view for the notification, including an image button.
            RemoteViews layout = new RemoteViews(getPackageName(), R.layout.notification);
            layout.setTextViewText(R.id.notification_title, getString(R.string.app_name));
            Intent clickIntent = new Intent();
            clickIntent.setAction(ACTION_DIALOG);

            PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), pendingRequestCode, clickIntent, pendingFlag);
            layout.setOnClickPendingIntent(R.id.notification_button,pendingIntent);
            builder.setContent(layout);

            // Notifications in Android 3.0 now have a standard mechanism for displaying large
            // bitmaps such as contact avatars. Here, we load an example image and resize it to the
            // appropriate size for large bitmaps in notifications.
            Bitmap largeIconTemp = BitmapFactory.decodeResource(res,
                    R.drawable.notification_default_largeicon);
            Bitmap largeIcon = Bitmap.createScaledBitmap(
                    largeIconTemp,
                    res.getDimensionPixelSize(android.R.dimen.notification_large_icon_width),
                    res.getDimensionPixelSize(android.R.dimen.notification_large_icon_height),
                    false);
            largeIconTemp.recycle();

            builder.setLargeIcon(largeIcon);

        notificationManager.notify(NOTIFICATION_DEFAULT, builder.getNotification());
 }


    PendingIntent getDialogPendingIntent(String dialogText) {
        return PendingIntent.getActivity(
                this,
                dialogText.hashCode(), // Otherwise previous PendingIntents with the same
                                       // requestCode may be overwritten.
                new Intent(ACTION_DIALOG)
                        .putExtra(Intent.EXTRA_TEXT, dialogText)
                        .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK),
                0);
    }

myBroad.class

public class myBroad extends BroadcastReceiver{
    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO Auto-generated method stub
        Toast.makeText(context, "received", Toast.LENGTH_SHORT).show();

        context.stopService(new Intent(context, myPlayService.class));  
    }
}

清单文件是：

 <application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/title_activity_main" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />


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

     <receiver android:name=".myBroad">
        <intent-filter >
<action android:name="android.intent.action.MEDIA_BUTTON"/>
    </intent-filter>

        </receiver>

    <service android:name="com.example.testservice.myPlayService" android:icon="@drawable/ic_action_search" android:label="@string/app_name" android:enabled="true"/>


</application>

Answer 1

因为myBroad是一个活动对象，而不是广播对象......

不是从活动扩展（继承），而是创建一个扩展broadcastreceiver的内部类，而只是直接从broadcastreceiver继承。

Answer 2

在您的方法getDialogPendingIntent中，您应该使用PendingIntent.getBroadcast代替PendingIntent.getActivity。这会导致PendingIntent推送广播。

并解决这个问题：

public class myBroad extends BroadcastReceiver

Answer 3

异常明确表示 - 您的myBroad必须像现在一样延伸BroadcastReceiver，而不是Activity。

PS：您应该考虑切换到正确的命名协议。所以它应该是MyBroad（类）但是myBroad（该类的对象）。即：

MyBroad myBroad = new MyBroad();

如何从通知中触发广播接收器

3 个答案: