Android TabHost+TabWidget出错

chaojinn 2009-09-03 07:54:56

参照http://developer.android.com/intl/zh-CN/guide/tutorials/views/hello-tabwidget.html的例子
<code>
<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/tabhost"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TabWidget
android:id="@android:id/tabs"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<FrameLayout
android:id="@android:id/tabcontent"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
android:id="@+id/textview1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="this is a tab" />
<TextView
android:id="@+id/textview2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="this is another tab" />
<TextView
android:id="@+id/textview3"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="this is a third tab" />
</FrameLayout>
</LinearLayout>
</TabHost>
</code>
首先在eclipse中，设计器报错
java.lang.NullPointerException
at android.widget.TabWidget.dispatchDraw(TabWidget.java:105)
at android.view.ViewGroup.drawChild(ViewGroup.java:1434)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1208)
at android.view.ViewGroup.drawChild(ViewGroup.java:1434)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1208)
at android.view.ViewGroup.drawChild(ViewGroup.java:1434)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1208)

然后，实际在模拟器上运行时，也报错：
09-03 13:47:34.639: ERROR/AndroidRuntime(1028): java.lang.NullPointerException
09-03 13:47:34.639: ERROR/AndroidRuntime(1028): at android.widget.TabHost.dispatchWindowFocusChanged(TabHost.java:285)
09-03 13:47:34.639: ERROR/AndroidRuntime(1028): at android.view.ViewGroup.dispatchWindowFocusChanged(ViewGroup.java:640)
09-03 13:47:34.639: ERROR/AndroidRuntime(1028): at android.view.ViewGroup.dispatchWindowFocusChanged(ViewGroup.java:640)
09-03 13:47:34.639: ERROR/AndroidRuntime(1028): at android.view.ViewGroup.dispatchWindowFocusChanged(ViewGroup.java:640)

抓狂中，求达人指点

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