MainActivity如下: 
 
package cn.testshape; 
import android.os.Bundle; 
import android.app.Activity; 
/** 
* Demo描述: 
* 自定义shape的使用 
*/ 
public class MainActivity extends Activity { 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
setContentView(R.layout.main); 
} 
} 
 main.xml如下: 
 
<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" 
> 
<Button 
android:layout_width="250dip" 
android:layout_height="50dip" 
android:text="测试自定义shape的使用" 
android:background="@drawable/background_selector" 
android:textColor="@drawable/textcolor_selector" 
android:layout_centerInParent="true" 
android:gravity="center" 
/> 
</RelativeLayout> 
 background_selector.xml如下: 
 
<?xml version="1.0" encoding="utf-8"?> 
<selector xmlns:android="http://schemas.android.com/apk/res/android" > 
<item android:drawable="@drawable/pressed_shape" android:state_pressed="true"/> 
<item android:drawable="@drawable/default_shape"/> 
</selector> 
 default_shape.xml如下: 
 
<?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" > 
<!-- 定义边框颜色 --> 
<solid android:color="#d1d1d1" /> 
<!-- 定义圆角弧度 --> 
<corners 
android:bottomLeftRadius="4dp" 
android:bottomRightRadius="4dp" 
android:topLeftRadius="4dp" 
android:topRightRadius="4dp" 
/> 
</shape> 
 pressed_shape.xml如下: 
 
<?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" > 
<!-- 定义边框颜色 --> 
<solid android:color="#7bb3f8" /> 
<!-- 定义圆角弧度 --> 
<corners 
android:bottomLeftRadius="4dp" 
android:bottomRightRadius="4dp" 
android:topLeftRadius="4dp" 
android:topRightRadius="4dp" 
/> 
</shape> 
 textcolor_selector.xml如下: 
 
<?xml version="1.0" encoding="utf-8"?> 
<selector xmlns:android="http://schemas.android.com/apk/res/android" > 
<item android:color="#ffffff" android:state_pressed="true"/> 
<item android:color="#000000"/> 
</selector>