Android使用自定义ImageView为图片添加边框

package com.wang.thomas.imageviewbounds;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.widget.ImageView;

public class BoundsImageView extends ImageView {
private Paint paint = new Paint();
private Rect rect = new Rect();

public BoundsImageView(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
}

public BoundsImageView(Context context) {
super(context);
// TODO Auto-generated constructor stub
}

@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);

paint.setColor(Color.RED);
paint.setAntiAlias(true);
paint.setStrokeWidth(5.0f);	//设置画笔宽度
paint.setStyle(Paint.Style.STROKE);	//设置画笔为线条模式

canvas.getClipBounds(rect);	//获取到ImageView的外轮廓矩形

canvas.drawRect(rect, paint);	//绘制这个矩形，获得一个边框
}
}