ImageView设置边框的两种方式

package cc.testimageviewbounds;

import android.os.Bundle;
import android.app.Activity;
/**
* Demo描述:
* 给ImageView添加边框的两种实现方式
*
* 方式一:
* 利用自定义的shape-->即此处的imageviewboundshape.xml
* 且为ImageView设置background,即代码:
* android:background="@drawable/imageviewboundshape"
*
* 方式二:
* 自定义ImageView
*
*/
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}

package cc.testimageviewbounds;

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 ImageViewSubClass extends ImageView {

public ImageViewSubClass(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}

public ImageViewSubClass(Context context, AttributeSet attrs) {
super(context, attrs);
}

public ImageViewSubClass(Context context) {
super(context);
}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);

//获取控件需要重新绘制的区域
Rect rect=canvas.getClipBounds();
rect.bottom--;
rect.right--;
Paint paint=new Paint();
paint.setColor(Color.RED);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(3);
canvas.drawRect(rect, paint);
}

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
>

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="给ImageView添加边框的两种方式"
android:layout_centerHorizontal="true"
android:layout_marginTop="65dip"
/>
<ImageView
android:id="@+id/firstImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_launcher"
android:layout_centerHorizontal="true"
android:layout_marginTop="150dip"
android:background="@drawable/imageviewboundshape"
/>
<cc.testimageviewbounds.ImageViewSubClass
android:id="@+id/secondImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_launcher"
android:layout_centerHorizontal="true"
android:layout_marginTop="250dip"
/>

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<!-- 定义矩形rectangle -->
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle"  >

<!-- 设置边框的大小和颜色 -->
<stroke android:width="3dip" android:color="#ff0000" />

<!-- 设置矩形内的颜色,此处为透明色 -->
<solid android:color="@android:color/transparent"/>

<!-- 定义圆角弧度 -->
<corners
android:bottomLeftRadius="4dp"
android:bottomRightRadius="4dp"
android:topLeftRadius="4dp"
android:topRightRadius="4dp"
/>

</shape>