我正在尝试使用底部渐变alpha遮罩位图。渐变大小固定且与位图大小无关。但是它绘制不正确:渐变底部在顶部,然后是顶部。
有什么问题吗?
以下是示例代码:
以下是示例代码:
final int GRADIENT_HEIGHT = 32;
public Bitmap addGradient(Bitmap src) {
int w = src.getWidth();
int h = src.getHeight();
Bitmap overlay = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(overlay);
canvas.drawBitmap(src, 0, 0, null);
Paint paint = new Paint();
LinearGradient shader = new LinearGradient(0, 0, 0, GRADIENT_HEIGHT, 0xFFFFFFFF, 0x00FFFFFF, TileMode.REPEAT);
paint.setShader(shader);
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
canvas.drawRect(0, h - GRADIENT_HEIGHT, w, h, paint);
return overlay;
}
谢谢!