camera startPreview failed

Question

I am creating a camera app but I have problems on startPreview, it sends me:

java.lang.RuntimeException: startPreview failed

h

Answer 1

I have solved deleting some lines in surfaceChanged

 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.
        Log.d("Function", "surfaceChanged iniciado");
        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();

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

So the error must be in i one of these lines:

Parameters parameters= mCamera.getParameters();
    parameters.setPreviewSize(w, h);
    mCamera.setParameters(parameters);

Someone could explain me what was wrong in those lines?