android为什么我RadioGroup里面放2个RadioButton没问题，放4个就出错

Question

Caused by: android.view.InflateException: Binary XML file line #65: Binary XML file line #65: Error inflating class
Caused by: android.view.InflateException: Binary XML file line #65: Error inflating class
Caused by: java.lang.reflect.InvocationTargetException

 <RadioGroup
        android:id="@+id/main_tab_group"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:orientation="horizontal"
        android:layout_alignParentBottom="true"
        android:background="@color/colorPrimary"
        >
        <RadioButton
            android:id="@+id/news"
            style="@style/maintabbutton"
            android:background="@drawable/main_tab_news"
            />
        <RadioButton
            android:id="@+id/topic"
            style="@style/maintabbutton"
            android:background="@drawable/main_tab_topic"/>

        <RadioButton
            android:id="@+id/practice"
            style="@style/maintabbutton"
            android:background="@drawable/main_tab_practice"
            />

        <RadioButton
            android:id="@+id/video"
            style="@style/maintabbutton"
            android:background="@drawable/main_tab_video"/>
 </RadioGroup>

    maintabbutton：

 <style name="maintabbutton">
        <item name="android:layout_weight">1</item>
        <item name="android:layout_height">wrap_content</item>
        <item name="android:gravity">center_horizontal</item>
        <item name="android:button">@null</item>
    </style>

Answer 1

5个我都放过，一点问题没有，下面是布局：

 <RadioGroup
        android:id="@+id/radio_group"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@drawable/bottom_tab_bg"
        android:orientation="horizontal" >

        <RadioButton
            android:id="@+id/rb_home"
            style="@style/ButtonTabStyle"
            android:drawableTop="@drawable/btn_tab_home_selector"
            android:text="@string/radio_button_home" />

        <RadioButton
            android:id="@+id/rb_news"
            style="@style/ButtonTabStyle"
            android:drawableTop="@drawable/btn_tab_news_selector"
            android:text="@string/radio_button_news" />

        <RadioButton
            android:id="@+id/rb_services"
            style="@style/ButtonTabStyle"
            android:drawableTop="@drawable/btn_tab_services_selector"
            android:text="@string/radio_button_smartservice" />

        <RadioButton
            android:id="@+id/rb_govaffairs"
            style="@style/ButtonTabStyle"
            android:drawableTop="@drawable/btn_tab_govaffairs_selector"
            android:text="@string/radio_button_govaffairs" />

        <RadioButton
            android:id="@+id/rb_setting"
            style="@style/ButtonTabStyle"
            android:drawableTop="@drawable/btn_tab_setting_selector"
            android:text="@string/radio_button_setting" />
    </RadioGroup>

 <style name="ButtonTabStyle">
        <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:drawablePadding">3dp</item>
        <item name="android:padding">5dp</item>
        <item name="android:textColor">@drawable/btn_tab_text_selector</item>
        <item name="android:layout_weight">1</item>
        <item name="android:gravity">center</item>
    </style>