Android Wear 开发中遇到的 CardFrame can host only one direct child

Caused by: java.lang.IllegalStateException: CardFrame can host only one direct child
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.support.wearable.view.CardFrame.addView(CardFrame.java:527)
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.view.LayoutInflater.rInflate(LayoutInflater.java:810)
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:378)
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.app.Activity.setContentView(Activity.java:2145)
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at tech.androidstudio.cardframedemoseconde.MainActivity.onCreate(MainActivity.java:15)
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.app.Activity.performCreate(Activity.java:5990)
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387) 
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.app.ActivityThread.access$800(ActivityThread.java:151) 
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) 
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:102) 
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:135) 
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:5254) 
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method) 
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372) 
02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 

02-29 23:57:35.233 20551-20551/tech.androidstudio.cardframedemoseconde E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 

原因 ：

CardFrame 只能有一个子组件 ，而我的 代码里面是两个TextView 所以错了 

<android.support.wearable.view.BoxInsetLayout  xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:app="http://schemas.android.com/apk/res-auto"  xmlns:tools="http://schemas.android.com/tools" android:id="@+id/watch_view_stub"  android:layout_width="match_parent"  android:layout_height="match_parent"  >
    <android.support.wearable.view.CardScrollView  android:id="@+id/cardscrollview"  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:gravity="bottom">
        <android.support.wearable.view.CardFrame  android:layout_width="match_parent"  android:layout_height="fill_parent">
            <TextView  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:text="Hello World"/>
            <TextView  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:text="Desctiption"/>

        </android.support.wearable.view.CardFrame>

    </android.support.wearable.view.CardScrollView>


</android.support.wearable.view.BoxInsetLayout>

解决的办法：

添加一个 LinearLayout来包裹 刚才的 两个TextView。

<android.support.wearable.view.CardFrame  android:layout_width="match_parent"  android:layout_height="fill_parent">
    <LinearLayout  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:orientation="vertical">
    <TextView  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:text="Hello World"/>
    <TextView  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:text="Desctiption"/>
    </LinearLayout>

</android.support.wearable.view.CardFrame>