android 一个典型的drawable

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="false">
    <shape android:shape="rectangle" >
        <!-- 填充的颜色 -->
        <solid android:color="#3090fe"></solid>
        <!-- 设置按钮的四个角为弧形 -->
        <!-- android:radius 弧形的半径 -->
        <corners android:radius="6dp" />
        <!-- padding：Button里面的文字与Button边界的间隔 -->
        <padding android:bottom="2dp" android:left="2dp" android:right="2dp" android:top="2dp" />
    </shape>
</item>
<item android:state_pressed="true">
    <shape android:shape="rectangle">
        <solid android:color="#3090fe" />
        <corners android:radius="6dp" />
    </shape>
</item>
</selector>

<?xml version='1.0' encoding='utf-8'?>
<shape xmlns:android=
    'http://schemas.android.com/apk/res/android'>
    <solid android:color='#D04349' />
    <corners
        android:topLeftRadius='@dimen/dp_2'
        android:topRightRadius='@dimen/dp_2'
        android:bottomRightRadius='@dimen/dp_2'
        android:bottomLeftRadius='@dimen/dp_2'/>

    <stroke
        android:width='1dp'
        android:color='#D04349'/>

</shape>