"ScrollView can host only one direct child"问题解决了

1. 问题叙述性说明：

（请注意以下几点大胆）。

ScrollView作为顶层view时报错，直接导致apk崩溃。具体错误信息例如以下：

12-21 09:12:15.150: D/AndroidRuntime(7726): Shutting down VM
12-21 09:12:15.150: W/dalvikvm(7726): threadid=1: thread exiting with uncaught exception (group=0x416402a0)
12-21 09:12:15.160: E/AndroidRuntime(7726): FATAL EXCEPTION: main
12-21 09:12:15.160: E/AndroidRuntime(7726): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.project.fish.app/com.my.act.activity.my.MyFA}: java.lang.IllegalStateException: ScrollView can host only one direct child
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2110)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.app.ActivityThread.access$700(ActivityThread.java:140)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1237)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.os.Handler.dispatchMessage(Handler.java:99)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.os.Looper.loop(Looper.java:137)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.app.ActivityThread.main(ActivityThread.java:4921)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at java.lang.reflect.Method.invokeNative(Native Method)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at java.lang.reflect.Method.invoke(Method.java:511)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at dalvik.system.NativeStart.main(Native Method)
12-21 09:12:15.160: E/AndroidRuntime(7726): Caused by: java.lang.IllegalStateException: ScrollView can host only one direct child
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.widget.ScrollView.addView(ScrollView.java:316)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.view.LayoutInflater.rInflate(LayoutInflater.java:750)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:307)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.app.Activity.setContentView(Activity.java:1924)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at com.my.act.InitTitlebar(MyFA.java:113)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at com.ui.activity.base.BaseFA.onCreate(BaseFA.java:29)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at com.fish.ui.activity.my.MyFA.onCreate(MyFA.java:169)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.app.Activity.performCreate(Activity.java:5206)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
12-21 09:12:15.160: E/AndroidRuntime(7726):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)
12-21 09:12:15.160: E/AndroidRuntime(7726):  ... 11 more

2. 分析：

从错误信息ScrollView can host only one direct child
可见，是xml的错误。以下列出错误的xml文件：

<?xml version="1.0" encoding="utf-8"?

>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@color/WhiteColor"
    android:scrollbars="vertical" >

        <!-- =================1. image ========================= -->

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:orientation="horizontal"
            android:paddingTop="15dip" >

            <ImageView
                android:id="@+id/imageView_pic"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:contentDescription="text"
                android:scaleType="fitCenter"
                android:src="@drawable/empty_photo" />
        </LinearLayout>
       

        <!-- ========================= 2. detail ================= -->

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="32dp"
            android:layout_marginTop="10dp"
            android:orientation="vertical" >

            <TextView
                android:id="@+id/text_prompt"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:layout_marginLeft="5dp"
                android:gravity="center"
                android:text="@string/text_detail"
                android:textSize="15dip" />
        </LinearLayout>
       
        <!-- ========================= 3. line ================= -->
       
        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="32dp"
            android:layout_marginTop="4dp"
            android:orientation="vertical" >

            <TextView
                android:layout_width="fill_parent"
                android:layout_height="2dp"
                android:background="@color/lightgray" />
        </LinearLayout>

</ScrollView>

，这个ScrollView中包括3个LinerLayout。

3. 解决：

从错误信息，我们就知道，须要scrollview不能有多个child，所以，我在3个layout外，又加了一个layout。使3个layou成为这个新加的layout的子view，问题解决。

以下是正确的xml定义：

<?

xml version="1.0" encoding="utf-8"?

>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@color/WhiteColor"
    android:scrollbars="vertical" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:paddingTop="15dip" >

        <!-- =================1. image ========================= -->

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:orientation="horizontal"
            android:paddingTop="15dip" >

            <ImageView
                android:id="@+id/imageView_pic"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:contentDescription="text"
                android:scaleType="fitCenter"
                android:src="@drawable/empty_photo" />
        </LinearLayout>
       

        <!-- ========================= 2. detail ================= -->

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="32dp"
            android:layout_marginTop="10dp"
            android:orientation="vertical" >

            <TextView
                android:id="@+id/text_prompt"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:layout_marginLeft="5dp"
                android:gravity="center"
                android:text="@string/text_detail"
                android:textSize="15dip" />
        </LinearLayout>
       
        <!-- ========================= 3. line ================= -->
       
        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="32dp"
            android:layout_marginTop="4dp"
            android:orientation="vertical" >

            <TextView
                android:layout_width="fill_parent"
                android:layout_height="2dp"
                android:background="@color/lightgray" />
        </LinearLayout>
</LinearLayout>

</ScrollView>