设置一个带小三角形的选项卡

Question

我想在程序中把选项卡像以下案例显示，选项卡图像下面有一个小三角形。有实现的方法吗？使用代码或文字形式都可以。

Answer 1

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- Non focused states -->
    <item android:state_focused="false" android:state_selected="false" android:state_pressed="false" android:drawable="@drawable/tab_unselected" />
    <item android:state_focused="false" android:state_selected="true" android:state_pressed="false" android:drawable="@drawable/tab_selected" />
    <!-- Focused states -->
    <item android:state_focused="true" android:state_selected="false" android:state_pressed="false" android:drawable="@drawable/tab_focus" />
    <item android:state_focused="true" android:state_selected="true" android:state_pressed="false" android:drawable="@drawable/tab_focus" />
    <!-- Pressed -->
    <item android:state_pressed="true" android:drawable="@drawable/tab_press" />
</selector>