Android自定义Drawable实现圆角效果

packagecom.mydrawable.musk;
 
importandroid.graphics.Bitmap;
importandroid.graphics.BitmapShader;
importandroid.graphics.Canvas;
importandroid.graphics.ColorFilter;
importandroid.graphics.Paint;
importandroid.graphics.PixelFormat;
importandroid.graphics.Shader;
importandroid.graphics.drawable.Drawable;
 
/**
 * Created by musk.
 */
 
publicclassCircleDrawableextendsDrawable {
 
 privatePaint mPaint;
 privateintmWidth;
 privateBitmap mBitmap;
 
 publicCircleDrawable(Bitmap bitmap) {
 mBitmap = bitmap;
 //着色器，设置横向和纵向的着色模式为平铺
 BitmapShader bitmapShader =newBitmapShader(mBitmap,
  Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
 
 mPaint =newPaint();
 mPaint.setAntiAlias(true);
 mPaint.setDither(true);
 mPaint.setShader(bitmapShader);
 mWidth = Math.min(mBitmap.getWidth(), mBitmap.getHeight());
 }
 
 //绘制
 @Override
 publicvoiddraw(Canvas canvas) {
 canvas.drawCircle(mWidth /2, mWidth /2, mWidth /2, mPaint);
 }
 
 //设置透明度值
 @Override
 publicvoidsetAlpha(intalpha) {
 mPaint.setAlpha(alpha);
 }
 
 //设置颜色过滤器
 @Override
 publicvoidsetColorFilter(ColorFilter colorFilter) {
 mPaint.setColorFilter(colorFilter);
 }
 
 //返回不透明度
 @Override
 publicintgetOpacity() {
 returnPixelFormat.TRANSLUCENT;
 }
 
 //返回图片实际的宽高
 @Override
 publicintgetIntrinsicWidth() {
 returnmWidth;
 }
 
 @Override
 publicintgetIntrinsicHeight() {
 returnmWidth;
 }
}