android图片蒙层

这里我们使用一个自定义view来为图片蒙层。该方法投机取巧&＃xff0c;直接把一张有透明效果的图片直接画到原图上。tranparent.png那张图片可以换成用bitmap自己画&＃xff0c;以后改进。先上效果图:上面是原图&＃xff0c;下面是蒙层后的效果

public class CenterImage extends ImageView {
private Paint paint;
private boolean isCenterImgShow;
private Bitmap bitmap;
public void setCenterImgShow(boolean centerImgShow) {
isCenterImgShow &＃61; centerImgShow;
if (isCenterImgShow) {
bitmap &＃61; BitmapFactory.decodeResource(getResources(), R.drawable.transparent);
invalidate();
}
}
public CenterImage(Context context) {
super(context);
init();
}
public CenterImage(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public CenterImage(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
paint &＃61; new Paint();
}
&＃64;Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (isCenterImgShow && bitmap !&＃61; null) {
//从中心点开始画
canvas.drawBitmap(bitmap, getMeasuredWidth() / 2 - bitmap.getWidth() / 2, getMeasuredHeight() / 2 - bitmap.getHeight() / 2, paint);
}
}
}

android:layout_below&＃61;"&＃64;id/image"
android:id&＃61;"&＃64;&＃43;id/goodsImage"
android:layout_width&＃61;"wrap_content"
android:layout_height&＃61;"wrap_content"
android:src&＃61;"&＃64;drawable/dog" />

调用&＃xff1a;

CenterImage mGoodsImg &＃61;(CenterImage)findViewById(R.id.goodsImage);
mGoodsImg.setCenterImgShow(true);

透明图片&＃xff1a;