Android: creating a Bitmap with SurfaceView conten

问题:

I'm afraid to already have the unfortunate answer to this question but just in case... I'm using a SurfaceView to do some image processing with bitmaps (lights and colors modifications) and I would need to import the modified bitmap (i.e. the content of the SurfaceView) in a new bitmap so that I can save it as an image file.

I've been looking around and it seems that it's possible to get a bitmap from View.getDrawingCache() but it doesn't work with SurfaceView. All I get is an empty bitmap.

Is there any solution to this?

Thanks

回答1:

Can you draw your SurfaceView onto a Canvas that's backed by a Bitmap?

    // be sure to call the createBitmap that returns a mutable Bitmap
    Bitmap b = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888); 
    Canvas c = new Canvas(b);
    yourSurfaceView.draw(c);

回答2:

There is no simple way to capture frames of SurfaceView, so you can consider using TextureView instead of SurfaceView: the Bitmap can be retrieved using textureView.getBitmap() method.

回答3:

For API levels >=24, use the PixelCopy API. Here's an example inside an ImageView:

public void DrawBitmap(){
    Bitmap surfaceBitmap = Bitmap.createBitmap(600, 600, Bitmap.Config.ARGB_8888);
    PixelCopy.OnPixelCopyFinishedListener listener = copyResult -> {
        // success/failure callback
    };

    PixelCopy.request(YourSurfaceView, surfaceBitmap,listener,getHandler());
    // visualize the retrieved bitmap on your imageview
    setImageBitmap(plotBitmap);
    }
}