rgGroup = (RadioGroup) findViewById(R.id.re_group);     rbWeiHui = (RadioButton) findViewById(R.id.rb_wei_hui);     rbAdd = (RadioButton) findViewById(R.id.rb_add);     rbMine = (RadioButton) findViewById(R.id.rb_mine);      //定義底部標簽圖片大小     Drawable drawableWeiHui = getResources().getDrawable(R.drawable.btn_tab_wei_hui_selector);     drawableWeiHui.setBounds(0, 0, 69, 69);//第一0是距左右邊距離，第二0是距上下邊距離，第三69長度,第四寬度     rbWeiHui.setCompoundDrawables(null, drawableWeiHui, null, null);//只放上面      Drawable drawableAdd = getResources().getDrawable(R.drawable.btn_tab_add_selector);     drawableAdd.setBounds(0, 0, 168, 120);     rbAdd.setCompoundDrawables(drawableAdd, null, null, null);      Drawable drawableRight = getResources().getDrawable(R.drawable.btn_tab_mine_selector);     drawableRight.setBounds(0, 0, 69, 69);     rbMine.setCompoundDrawables(null, drawableRight, null, null);      //初始化底部標簽     rgGroup.check(R.id.rb_wei_hui);// 默認勾選首頁，初始化時候讓首頁默認勾選 

<RadioGroup     android:id="@+id/re_group"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:background="@color/app_bg_color"     android:orientation="horizontal" >      <RadioButton       android:id="@+id/rb_wei_hui"       style="@style/BottomTabStyle"       android:layout_marginTop="5dp"       android:drawableTop="@drawable/btn_tab_wei_hui_selector"       android:textSize="12sp"       android:text="xx" />      <RadioButton       android:id="@+id/rb_add"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:background="@color/app_bg_color"       android:button="@null"       android:drawableTop="@mipmap/ic_add_selected"       android:gravity="center"       android:paddingTop="10dip" />      <RadioButton       android:id="@+id/rb_mine"       style="@style/BottomTabStyle"       android:layout_marginTop="5dp"       android:drawableTop="@drawable/btn_tab_mine_selector"       android:textSize="12sp"       android:text="xx" />   </RadioGroup> 

<?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android" >    <item android:drawable="@mipmap/ic_mine_selected" android:state_checked="true" />   <item android:drawable="@mipmap/ic_mine_normal" />   </selector> 

<!-- 低欄RadioButton首頁下面的標簽的樣式 -->   <style name="BottomTabStyle">     <item name="android:layout_width">wrap_content</item>     <item name="android:layout_height">wrap_content</item>     <item name="android:layout_gravity">center_vertical</item>     <item name="android:button">@null</item>     <item name="android:padding">5dp</item>     <item name="android:drawablePadding">3dp</item>     <item name="android:textColor">@drawable/btn_tab_text_selector</item>     <item name="android:layout_weight">1</item>     <item name="android:gravity">center</item>     <item name="android:layout_marginTop">5dp</item>   </style>