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，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，以后改进。先上效果图:上面是原图，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 = centerImgShow; if (isCenterImgShow) { bitmap = 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 = new Paint(); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); if (isCenterImgShow && bitmap != null) { //从中心点开始画 canvas.drawBitmap(bitmap, getMeasuredWidth() / 2 - bitmap.getWidth() / 2, getMeasuredHeight() / 2 - bitmap.getHeight() / 2, paint); } } }<com.epos.testrxjava.CenterImageandroid:layout_below="@id/image"android:id="@+id/goodsImage"android:layout_width=“wrap_content"android:layout_height=“wrap_content"android:src="@drawable/dog” />调用：CenterImage mGoodsImg =(CenterImage)findViewById(R.id.goodsImage);mGoodsImg.setCenterImgShow(true);透明图片：