Question

我正在尝试制作相机应用程序，但是只要我拍照，相机的预览就会停止，如果我再次点击我的捕捉按钮，应用程序就会崩溃。可能是什么原因造成的？我的错误日志：

    07-04 17:31:36.278    3943-3943/com.asim.spycamera E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.asim.spycamera, PID: 3943
java.lang.RuntimeException: takePicture failed
        at android.hardware.Camera.native_takePicture(Native Method)
        at android.hardware.Camera.takePicture(Camera.java:1436)
        at android.hardware.Camera.takePicture(Camera.java:1381)
        at com.asim.spycamera.MainActivity$2.onClick(MainActivity.java:91)
        at android.view.View.performClick(View.java:4780)
        at android.view.View$PerformClick.run(View.java:19866)
        at android.os.Handler.handleCallback(Handler.java:739)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5254)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

我的主要活动代码：

    public class MainActivity extends ActionBarActivity {

private Camera mCamera;
private CameraPreview mPreview;
public static final String TAG = "MAIN-TAG";
public static final int MEDIA_TYPE_IMAGE = 1;
public static final int MEDIA_TYPE_VIDEO = 2;


private Camera.PictureCallback mPicture = new Camera.PictureCallback() {

    @Override
    public void onPictureTaken(byte[] data, Camera camera) {

        File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
        if (pictureFile == null){
            mPreview.safeToTakePicture = true;
            Log.d(TAG, "Error creating media file, check storage permissions ");
            return;
        }

        try {
            FileOutputStream fos = new FileOutputStream(pictureFile);
            fos.write(data);
            fos.close();
        } catch (FileNotFoundException e) {
            Log.d(TAG, "File not found: " + e.getMessage());
        } catch (IOException e) {
            Log.d(TAG, "Error accessing file: " + e.getMessage());
        }
        mPreview.safeToTakePicture = true;
    }
};

/** A safe way to get an instance of the Camera object. */
public static Camera getCameraInstance(){
    Camera c = null;
    try {
        c = Camera.open(); // attempt to get a Camera instance
    }
    catch (Exception e){
        // Camera is not available (in use or does not exist)
    }
    return c; // returns null if camera is unavailable
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // Create an instance of Camera
    mCamera = getCameraInstance();

    // Create our Preview view and set it as the content of our activity.
    mPreview = new CameraPreview(this, mCamera);
    FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
    preview.addView(mPreview);

    // Add a listener to the Capture button
    Button captureButton = (Button) findViewById(R.id.button_capture);
    captureButton.setOnClickListener(
            new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    // get an image from the camera
                    if (mPreview.safeToTakePicture) {
                        mCamera.takePicture(null, null, mPicture);
                        mPreview.safeToTakePicture = false;
                    }
                }
            }
    );

}

我的CameraPreview类代码

    public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {

private SurfaceHolder mHolder;
private Camera mCamera;
public static final String TAG = "CAMERA-TAG";
public boolean safeToTakePicture = false;

public CameraPreview(Context context, Camera camera) {
    super(context);
    mCamera = camera;

    // Install a SurfaceHolder.Callback so we get notified when the
    // underlying surface is created and destroyed.
    mHolder = getHolder();
    mHolder.addCallback(this);
    // deprecated setting, but required on Android versions prior to 3.0
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

public void surfaceCreated(SurfaceHolder holder) {
    // The Surface has been created, now tell the camera where to draw the preview.
    try {
        mCamera.setPreviewDisplay(holder);
        mCamera.startPreview();
    } catch (IOException e) {
        Log.d(TAG, "Error setting camera preview: " + e.getMessage());
    }
}

public void surfaceDestroyed(SurfaceHolder holder) {
    // empty. Take care of releasing the Camera preview in your activity.
}

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
    // If your preview can change or rotate, take care of those events here.
    // Make sure to stop the preview before resizing or reformatting it.

    if (mHolder.getSurface() == null){
        // preview surface does not exist
        return;
    }

    // stop preview before making changes
    try {
        mCamera.stopPreview();
    } catch (Exception e){
        // ignore: tried to stop a non-existent preview
    }

    // set preview size and make any resize, rotate or
    // reformatting changes here

    // start preview with new settings
    try {
        mCamera.setPreviewDisplay(mHolder);
        mCamera.startPreview();;
        safeToTakePicture = true;

    } catch (Exception e){
        Log.d(TAG, "Error starting camera preview: " + e.getMessage());
    }
}

Answer 1

在onPictureTaken()中，您应该明确呼叫Camera.startPreview()（请参阅https://stackoverflow.com/a/10490957/192373）。

拍摄单张照片后Android应用程序崩溃了吗？

1 个答案: