converting a canvas into bitmap image in android

Question

I am trying to develop an app on canvas,I am drawing a bitmap on the canvas. After drawing, I am trying to convert into bitmap image.

Can anyone give me a suggestion?

Answer 1

Advice depends upon what you are trying to do.

If you are concerned that your controls take a long time to draw, and you want to draw to a bitmap so you can blit the bitmap rather than re-drawing via a canvas, then you don't want to be double-guessing the platform - controls automatically cache their drawing to temporary bitmaps, and these can even be fetched from the control using getDrawingCache()

If you want to draw using a canvas to a bitmap, the usual recipe is:

1. Create a bitmap of the correct size using Bitmap.createBitmap()
2. Create a canvas instance pointing that this bitmap using Canvas(Bitmap) constructor
3. Draw to the canvas
4. Use the bitmap

Answer 2

So you create a new Bitmap, for example:

Bitmap myBitmap = new Bitmap( (int)Width, (int)Height, Config.RGB_565 )

with width and height being the same as your canvas.

Next, use canvas.setBitmap(myBitmap), but not drawBitmap().

After you call setBitmap, all what you draw on canvas is in fact, drawing on your myBitmap going by the example code I have illustrated.

Edit:

You can not create a bitmap directly such as:

Bitmap myBitmap = new Bitmap( (int)Width, (int)Height, Config.RGB_565 ); 

You must use instead:

Bitmap myBitmap = Bitmap.createBitmap( (int)Width, (int)Height, Config.RGB_565 );