IllegalStateException while adding bitmap to Canvas

Question

I was trying to set a bitmap image to a canvas using setBitMap ,at that time I got an IllegalStateException.This canvas have some images on it currently, I am trying to replace it. Any one have any idea why this happened?

Code Snippet

editBm = Bitmap.createBitmap(951, 552, Bitmap.Config.ARGB_8888);    
        Canvas mCanvas=new Canvas(editBm);
        eBit=LoadBMPsdcard(filePath); ---->returns a bitmap when the file path to the file is provided
        Log.i("BM size", editBm.getWidth()+"");
        mCanvas.setBitmap(eBit);

I am not getting any NullPointer errors and the method LoadBMPsdcard() is working good.

Please let me know about any ideas you have ...

Thanks in advance

Happy Coding

Answer 1

IllegalStateException could be thrown because you're loading a Bitmap (eBit) and use mCanvas.setBitmap(eBit) without checking if the bitmap is mutable. This is requiered to draw on the Bitmap. To make sure your Bitmap is mutable use:

eBit=LoadBMPsdcard(filePath);
Bitmap bitmap = eBit.copy(Bitmap.Config.ARGB_8888, true);
canvas.setBitmap(bitmap);

Answer 2

Try to use drawBitmap instead of the setBitmap. It looks like you've already set a bitmap to draw into by passing it to the canvas constructor, so now you just need to draw everything onto it.