Creating an empty bitmap and drawing though canvas in Android
I'd like to create an empty bitmap and 开发者_如何学Goset a canvas to that bitmap and then draw any shape on the bitmap.
This is probably simpler than you're thinking:
int w = WIDTH_PX, h = HEIGHT_PX;
Bitmap.Config conf = Bitmap.Config.ARGB_8888; // see other conf types
Bitmap bmp = Bitmap.createBitmap(w, h, conf); // this creates a MUTABLE bitmap
Canvas canvas = new Canvas(bmp);
// ready to draw on that bitmap through that canvas
Here's the official documentation on the topic: Custom Drawing
Do not use Bitmap.Config.ARGB_8888
Instead use int w = WIDTH_PX, h = HEIGHT_PX;
Bitmap.Config conf = Bitmap.Config.ARGB_4444; // see other conf types
Bitmap bmp = Bitmap.createBitmap(w, h, conf); // this creates a MUTABLE bitmap
Canvas canvas = new Canvas(bmp);
// ready to draw on that bitmap through that canvas
ARGB_8888 can land you in OutOfMemory issues when dealing with more bitmaps or large bitmaps. Or better yet, try avoiding usage of ARGB option itself.
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