FlashLight Widget崩溃

Question

试图为我的Android应用程序编写小部件。

onUpdate:

 @Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager,
                     int[] appWidgetIds) {


    RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.widget);
    Intent active = new Intent(context, Widget.class);
    active.setAction(ACTION_WIDGET_RECEIVER);
    active.putExtra("msg", "FLASHLIGHT");

    PendingIntent actionPendingIntent = PendingIntent.getBroadcast(context, 0, active, 0);

    remoteViews.setOnClickPendingIntent(R.id.widget_button, actionPendingIntent);
    appWidgetManager.updateAppWidget(appWidgetIds, remoteViews);

}

OnRecive:

@Override
public void onReceive(Context context, Intent intent) {
    String msg = "null";

    final String action = intent.getAction();
    if (ACTION_WIDGET_RECEIVER.equals(action)) {
        msg = intent.getStringExtra("msg");
        if (mCamera == null)
        {
            getCamera();
        }

            Toast.makeText(context, msg, Toast.LENGTH_SHORT).show();
        try
        {
            if(isFlashOn) { turnOffFlash(); }
            else { turnOnFlash(); }
        }
        catch (Exception e)
        {
            Log.e("ERROR --- > ",e.getMessage());
        }


    }
    super.onReceive(context, intent);

}


protected void turnOnFlash()
{
    params = mCamera.getParameters();
    params.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
    mCamera.setParameters(params);
    isFlashOn = true;
}

protected void turnOffFlash()
{
    params = mCamera.getParameters();
    params.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
    mCamera.setParameters(params);
    isFlashOn = false;
}

private void getCamera() {
    if (mCamera == null) {
        try {
            mCamera = Camera.open();
            params = mCamera.getParameters();
        }
        catch (RuntimeException e) {
            Log.e("Camera Error. Failed to Open. Error: ", e.getMessage());
        }
    }

}

错误：

09-11 14:39:40.595 80-373/？E/QualcommCameraHardware: native_access_parm: Error (没有这样的文件或目录)：fd 30，类型1，长度32，状态0 09-11 14:39:46.255 6096-6096/net.testapp.手电筒E/照相机错误。没能打开。错误:无法连接到相机服务09-11 14:39:46.275 6096-6096/net.testapp.手电筒E/AndroidRuntime:致命异常:主java.lang.RuntimeException:无法启动接收器net.testapp.flashlight.Widget: java.lang.NullPointerException: println在android.app.ActivityThread.access$1500(ActivityThread.java:153) at android.app.ActivityThread$H.handleMessage需要一条消息(( android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:5226) at java.lang.reflect.Method.invokeNative(原生方法)在java.lang.reflect.Method.invoke(Method.java:511) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit在com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562) at dalvik.system.NativeStart.main(原生方法)由: java.lang.NullPointerException: println需要在android.util.Log.println_native(原生方法)在android.util.Log.e(Log.java:231)在net.testapp.flashlight.Widget.onReceive(Widget.java:87)的消息。在android.app.ActivityThread.handleReceiver(ActivityThread.java:2503) .再多10点14:39:48.715 80-6121/？E/mm-摄像机8x- VFE :收到VFE停止ACK！ctrlCmd为NULL 09-11 14:40:45.935 5820-5921/com.android.vending E/PlayEventLogger:上传失败类java.net.UnknownHostException(无法解析主机"play.googleapis.com"：没有与主机名关联的地址) 09-11 14:41:59.745 6131-6131/com.android.Providers.E/跟踪:错误打开跟踪文件:没有这样的文件或目录(2) 09-1114:42:01.265 6151-6151/com.yanmodem.锁钟E/跟踪:打开跟踪跟踪错误文件:没有这样的文件或目录(2) 09-11 14:42:01.355 6165-6165/com.google.android.日历E/跟踪:打开跟踪文件错误:没有这样的文件或目录(2) 09-11 14:45:46.065 5820-5921/com.android.vending E/PlayEventLogger:上载失败类java.net.UnknownHostException(无法解析主机"play.googleapis.com"：没有与主机名关联的地址)

Answer 1

您需要使用服务，如下所示：

Public class widget extends service{

@Override
Public void onCreate{
    Super.on create();
}

@Override
Public void onStart {
    Super.onStart ();

    If(isFlashOn) {
//enter code to open camera and turn on flash
}else{
//enter code to release camera and turn off flash
      Stop self();
   }
}

@Override
Public void onDestroy {
      Super.on destroy();
}

@Override
Public Ibinder onBind {
      Return null;
}
}

Answer 2

删除"if (camera==null)“语句，只使用getCamera()；只因为它已经在其方法中使用了该语句。

另外，在mCamera.startPreview代码中添加“turnOnFLash；”，在turnOffFlash代码中停止预览。