Android - Unity3D: setVisibility(View.VISIBLE) crashes

Question

I have a unity project and I use a Android (java) plugin to get camera data. I draw this on a TextureView. I want to hide/show this view when I press a button in unity. But my app crashes when I setVisibility

onCreate

protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);

    //Reset data
    ResetData();

    //Create camera preview
    _camPreview = new CameraPreview();

    //Create texture view
    TextureView texView = new TextureView(this);

    //Initialize camera texutre
    _camPreview.Init(texView);

    //Add the texture view to unity
    UnityPlayer.currentActivity.addContentView(texView, new FrameLayout.LayoutParams(400, 400));
}

Camera Preview class:

public void Init(TextureView texView)
{
    //Save texture view
    _TextureView = texView;

    //Let this class listen to events of the surface
    _TextureView.setSurfaceTextureListener(this);
}

public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height)
{
    //Get camera
    _camera = Camera.open();
    _camera.setDisplayOrientation(90);

    //Set texture view data
    _TextureView.setLayoutParams(new FrameLayout.LayoutParams(425, 425, Gravity.CENTER));
    _TextureView.setTranslationY(-70);

    //Set dummy texture
    try {
        _camera.setPreviewTexture(surface);
    }
    catch (IOException e)
    {
        Log.e("Unity", "Error surface");
    }

    //Get parameters
    Camera.Parameters parameters = _camera.getParameters();

    //Set JPEG
    parameters.setPreviewFormat(ImageFormat.JPEG);

    //Set image size
    parameters.setPreviewSize(480, 320);

    //Set new parameters
    _camera.setParameters(parameters);
}

public void HideVideo()
{
    //Hide view
    _TextureView.setVisibility(View.INVISIBLE);
}

Is there an extra function I need to call, or may I only call it on certain times?

None of these thins work, they all make my app crash.

    _TextureView.setVisibility(View.INVISIBLE);
    _TextureView.setActivated(false);
    _TextureView.setAlpha(0);
    _TextureView.setTranslationY(-1000);

Answer 1

I suppose your _TextureView object is null;You have to initialize it correctly;

Answer 2

I have made a work around, now I set a boolean and in the onSurfaceTextureUpdated callback I set the alpha.

public void onSurfaceTextureUpdated(SurfaceTexture surface)
{
    //Visibility changed
    if(_isVisibleChanged == true)
    {
        //Show video
        if(_isVisible)
            _TextureView.setAlpha(1);

        //Hide video
        else
            _TextureView.setAlpha(0);

        //Visibility updated
        _isVisibleChanged = false;
    }
}

In any other function it crashes accept there.