1.drawable新建xml文件
```
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<solid android:color="#FFFFFF" />
<corners android:topLeftRadius="@dimen/start_button_radius" android:bottomLeftRadius="@dimen/start_button_radius"/>
<stroke android:width="1dp" android:color="@color/colorPrimary" />
<!-- android:topRightRadius="20dp"-->
<!-- android:bottomRightRadius="20dp"-->
</shape>
```
2.在value里新建dimens.xml (这是圆角)
```
<?xml version="1.0" encoding="utf-8"?>
<resources>
<dimen name="start_left_margin">50dp</dimen>
<dimen name="start_button_radius">7dp</dimen>
<dimen name="row_height">45dp</dimen>
<dimen name="login_title_top_margin">60dp</dimen>
</resources>
```
3.引用
```
android:background="@drawable/你的xml名字"
```