IllegalStateException while adding bitmap to Canvas

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 开发者_StackOverflowlet me know about any ideas you have ...

Thanks in advance

Happy Coding

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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);

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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.

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Canvas.setBitmap() throws IllegalStateException if and only if Bitmap.isMutable() returns true. Bitmap.createBitmap() builds an immutable Bitmap instance only, in all of its forms. To create a mutable bitmap you either use new Bitmap(), or Bitmap.copy(true), depending on whether you have a source bitmap that you want to start with. A typical block for me looks like:

Bitmap image = ...
Canvas c = new Canvas(image.isMutable()?image:image.copy(true));
...

This assumes, of course, that you don't mind clobbering the source Bitmap (which I generally don't but that's by no means universal).