getTabHost返回null

如何解决getTabHost返回null

| 我正在遵循TabLayout的说明。几乎所有内容都是该页面的精确副本。

public class DashboardActivity extends TabActivity {

问题在于，在此行“ 1”中，tabHost始终为null，这会导致在“ 2”基类中出现空指针异常。 我有什么想念的吗？

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    profile = Controller.getProfile();

    this.setContentView(R.layout.test);

    buildTabs();
}

private void buildTabs()
{
    Resources res = getResources(); // Resource object to get Drawables
    TabHost tabHost = getTabHost();// The activity TabHost

    if(tabHost != null)
    {
        // Initialize a TabSpec for each tab and add it to the TabHost
        TabSpec statementSpec = tabHost.newTabSpec(\"statements\").setIndicator(\"Statements (\" + profile.Statements.length + \")\",res.getDrawable(R.drawable.ic_tabs_statements))
                      .setContent(new Intent().setClass(DashboardActivity.this,SplashActivity.class));
        tabHost.addTab(statementSpec);

        TabSpec paymentSpec = tabHost.newTabSpec(\"payments\").setIndicator(\"Payments (\" + profile.Items.length + \")\",res.getDrawable(R.drawable.ic_tabs_payments))
                      .setContent(new Intent().setClass(DashboardActivity.this,SplashActivity.class));
        tabHost.addTab(paymentSpec);

        tabHost.setCurrentTab(0);
    }
}

布局

<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\"
        android:padding=\"5dp\">
        <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\"
            android:padding=\"5dp\" />
    </LinearLayout>
</TabHost>

可绘制状态列表

<selector xmlns:android=\"http://schemas.android.com/apk/res/android\">
    <!-- When selected,use grey -->
    <item android:drawable=\"@drawable/ic_tab_active\"
          android:state_selected=\"true\" />
    <!-- When not selected,use white-->
    <item android:drawable=\"@drawable/ic_tab_suspended\" />
</selector>

我什至尝试将可绘制状态列表中的图像从/ rex / drawable移至/ res / drawable-hdpi。我总是得到同样的错误。

05-31 21:22:23.753: ERROR/AndroidRuntime(647): FATAL EXCEPTION: main
05-31 21:22:23.753: ERROR/AndroidRuntime(647): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ftni.consumer/com.ftni.consumer.ui.DashboardActivity}: java.lang.NullPointerException
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1622)
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1638)
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at android.app.ActivityThread.access$1500(ActivityThread.java:117)
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:928)
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at android.os.Looper.loop(Looper.java:123)
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at android.app.ActivityThread.main(ActivityThread.java:3647)
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at java.lang.reflect.Method.invokeNative(Native Method)
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at java.lang.reflect.Method.invoke(Method.java:507)
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at dalvik.system.NativeStart.main(Native Method)
05-31 21:22:23.753: ERROR/AndroidRuntime(647): Caused by: java.lang.NullPointerException
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at android.app.TabActivity.onPostCreate(TabActivity.java:79)
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at android.app.Instrumentation.callActivityOnPostCreate(Instrumentation.java:1108)
05-31 21:22:23.753: ERROR/AndroidRuntime(647):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1605)

还有其他人在执行标准标签活动时遇到问题吗？关于我在做什么错的任何指示？     

解决方法

        尝试将所有buildTabs（）的代码放入onCreate（）方法中。     ,        写

tabHost.setup(); 

代替：

 tabHost = getTabHost();

这应该可以解决问题。