Java.lang.runtimeException：TakePicture即使在开始预览后仍然失败

Question

我的代码：

public void onClick(View v)
{
    if(getCamera() != null && CameraPreview.SAFE_TO_TAKE_PICTURE)
    {
        getCamera().startPreview();
        getCamera().takePicture(null, null, mJpegImageCallback);
    }
}

private PictureCallback mJpegImageCallback = new PictureCallback()
{
    public void onPictureTaken(byte[] data, Camera camera)
    {
        CameraPreview.SAFE_TO_TAKE_PICTURE = false;
        onCameraPictureTaken(data);
        BBLogUtils.logFlow("Camera: Image Taken");
    }
};

CameraPreview：

public void surfaceCreated(SurfaceHolder holder)
{
    // The Surface has been created, acquire the camera and tell it where
    // to draw.
    mCamera = Camera.open(0);
    mParameters = mCamera.getParameters();
    setCameraDisplayOrientation();
    mCamera.setPreviewDisplay(holder);
    if ( isAutoFocusSupported() )
        setFocus();
    if ( isFlashSupported() )
        setFlash(mFlashState);
}

public void surfaceDestroyed(SurfaceHolder holder)
{
    if ( mCamera != null )
    {
        mCamera.stopPreview();
        mCamera.release();
        mCamera = null;
    }
}

public void surfaceChanged(SurfaceHolder holder, int format, int width, int height)
{
    // Now that the size is known, set up the camera parameters and begin
    // the preview.
    mPreviewWidth = width;
    mPreviewHeight = height;
    Camera.Size previewSize = getBestPreviewSize(width, height);
    Camera.Size pictureSize = getOptimalImageSize();
    holder.setFormat(format);
    mParameters.setPreviewSize(previewSize.width, previewSize.height);
    mParameters.setPictureSize(pictureSize.width, pictureSize.height);
    mParameters.setJpegQuality(100);
    mCamera.setPreviewDisplay(holder);
    SAFE_TO_TAKE_PICTURE = true;
    setCameraParameters();
    handleFocus();
}

private void setCameraParameters()
{
    mCamera.stopPreview();
    mCamera.setParameters(mParameters);
    mCamera.startPreview();
}

我在某处读过你需要设置safe_to_take_picture需要在拍照之前进行检查，这样才能确保在调用takepicture之前已经开始预览。我甚至明确地这样做了。即使这样，我也会遇到以下异常：

java.lang.RuntimeException: takePicture failed
E/ACRA    ( 1180):  at android.hardware.Camera.native_takePicture(Native Method)
E/ACRA    ( 1180):  at android.hardware.Camera.takePicture(Camera.java:1100)
E/ACRA    ( 1180):  at android.hardware.Camera.takePicture(Camera.java:1045)
E/ACRA    ( 1180):  at CameraClickListener.onClick(CameraClickListener.java:38)
E/ACRA    ( 1180):  at CameraActivity$7.onClick(CameraActivity.java:200)
E/ACRA    ( 1180):  at android.view.View.performClick(View.java:4240)
E/ACRA    ( 1180):  at android.view.View$PerformClick.run(View.java:17721)
E/ACRA    ( 1180):  at android.os.Handler.handleCallback(Handler.java:730)
E/ACRA    ( 1180):  at android.os.Handler.dispatchMessage(Handler.java:92)
E/ACRA    ( 1180):  at android.os.Looper.loop(Looper.java:137)