Android 暂停时应用崩溃

Question

我有一个 android activity，它使用表面视图显示实时相机预览。一切正常，但是当我按下 phone 上的锁定按钮然后解锁我的 phone 或来自另一个 activity 的对话框（例如蓝牙传输或来电）覆盖我的时相机预览应用程序崩溃。我怀疑这是我的 onResume() 或 onPause() 活动的问题，因为我收到错误 "method called after release()"。但是，我不确定如何解决这个问题。

相机ACTIVITY：

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_camera_screen);
    setStatusBarColor();
    Display display = getWindowManager().getDefaultDisplay();
    final int height = display.getHeight();

    session = new SessionManager(getApplicationContext());
    try {
        mCamera = Camera.open();//you can use open(int) to use different cameras
    } catch (Exception e) {
        Log.d("ERROR", "Failed to get camera: " + e.getMessage());
    }


    if (mCamera != null) {
        mCameraView = new CameraPreview(this, mCamera);//create a SurfaceView to show camera data
        FrameLayout camera_view = (FrameLayout) findViewById(R.id.camera_view);
        camera_view.addView(mCameraView);//add the SurfaceView to the layout
        //rotate preview
        mCamera.setDisplayOrientation(90);
  //rotate camera
        Camera.Parameters p = mCamera.getParameters();
        p.setRotation(90);
        mCamera.setParameters(p);
    }
    @Override
protected void onPause() {
    super.onPause();
    if (mCamera != null) {
        mCamera.setPreviewCallback(null);
        mCameraView.getHolder().removeCallback(mCameraView);
        mCamera.release();
    }
}
@Override
public void onResume() {
    super.onResume();

    // Get the Camera instance as the activity achieves full user focus
    if (mCamera == null) {
        initializeCamera(); // Local method to handle camera initialization
    }
}



protected void initializeCamera(){
    // Get an instance of Camera Object
    try{
        mCamera = Camera.open();//you can use open(int) to use different cameras
    } catch (Exception e){
        Log.d("ERROR", "Failed to get camera: " + e.getMessage());
    }


    if(mCamera != null) {
        mCameraView = new CameraPreview(this, mCamera);//create a SurfaceView to show camera data
        FrameLayout camera_view = (FrameLayout)findViewById(R.id.camera_view);
        camera_view.addView(mCameraView);//add the SurfaceView to the layout
    }

}

Answer 1

尝试将此行添加到您的 onPause() 中：

camera_view.removeView(mCameraView);

Answer 2

onPause(){
...
mCamera.release(); // close mCamera, but not set it to null
//mCamera = null; // you need reset mCamera to trigger init method;
}
onResume(){
...
initializeCamera();// need mCamera == null
}

//If you find other problems.
//Add some codes in the initializeCamera().
{
//mCamera.setPreviewCallback("something");
//mCameraView.getHolder().addCallback(mCameraView);
}
//as onPause do.

Android 暂停时应用崩溃

Android App Crashes when paused

java

android

onresume

android-camera

onpause