相关疑难解决方法(0)

Canvas和Bitmap之间有什么关系？

Bitmap drawingBitmap = Bitmap.createBitmap(bmp1.getWidth(),
bmp1.getHeight(), bmp1.getConfig());
canvas = new Canvas(drawingBitmap);
paint = new Paint();
canvas.drawBitmap(bmp1, 0, 0, paint);
paint.setXfermode(new PorterDuffXfermode(android.graphics.PorterDuff.Mode.SCREEN));
canvas.drawBitmap(bmp2, 0, 0, paint);
compositeImageView.setImageBitmap(drawingBitmap);

我不明白这段代码.为什么drawingBitmap是bmp1和bmp2的组成？