java.lang.NullPointerException android

Question

這是我在控制檯中看到的異常，但我找不到解決方案。 這裏是我的代碼：

public class MainActivity extends TabActivity { 


    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 


     Resources res = getResources(); // Resource object to get Drawables 
     TabHost tabHost = getTabHost(); // The activity TabHost 
     TabHost.TabSpec spec; // Resusable TabSpec for each tab 

     Intent intent; // Reusable Intent for each tab // Create an Intent to launch an Activity for the tab (to be reused) 
     intent = new Intent().setClass(this, Collections.class); 
     spec = tabHost.newTabSpec("Collections").setIndicator("Collections") .setContent(intent); 
     tabHost.addTab(spec); 

     // Do the same for the other tabs 
     intent = new Intent().setClass(this, MyStampii.class); 
     spec = tabHost.newTabSpec("MyStampii").setIndicator("My Stampii") .setContent(intent); 
     tabHost.addTab(spec); 

     // Do the same for the other tabs 
     intent = new Intent().setClass(this, Notices.class); 
     spec = tabHost.newTabSpec("Notices").setIndicator("Notices") .setContent(intent); 
     tabHost.addTab(spec); 

     // Do the same for the other tabs 
     intent = new Intent().setClass(this, Tutorial.class); 
     spec = tabHost.newTabSpec("Tutorial").setIndicator("Tutorial") .setContent(intent); 
     tabHost.addTab(spec); 

     // Do the same for the other tabs 
     intent = new Intent().setClass(this, Settings.class); 
     spec = tabHost.newTabSpec("Settings").setIndicator("Settings") .setContent(intent); 
     tabHost.addTab(spec); 
     } 
} 

和main.xml中

<?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" 
     android:padding="5dp"> 
     <FrameLayout 
      android:id="@android:id/tabcontent" 
      android:layout_width="fill_parent" 
      android:layout_height="fill_parent" 
      android:layout_weight="1" 
      android:padding="5dp" /> 
     <TabWidget 
      android:id="@android:id/tabs" 
      android:layout_width="fill_parent" 
      android:layout_height="wrap_content" 
      android:layout_weight="0" /> 
    </LinearLayout> 
</TabHost> 

，這是例外：

[2011-07-15 09:39:19 - ddms]null 
java.lang.NullPointerException 
    at com.android.ddmlib.Client.sendAndConsume(Client.java:572) 
    at com.android.ddmlib.HandleHello.sendHELO(HandleHello.java:142) 
    at com.android.ddmlib.HandleHello.sendHelloCommands(HandleHello.java:65) 
    at com.android.ddmlib.Client.getJdwpPacket(Client.java:671) 
    at com.android.ddmlib.MonitorThread.processClientActivity(MonitorThread.java:317) 
    at com.android.ddmlib.MonitorThread.run(MonitorThread.java:263) 

任何想法？無論如何，感謝您的幫助！

Answer 1

以下鏈接是Android的標籤佈局的教程請參考更多的參考：http://www.androidpeople.com/android-tabhost-tutorial-part-1

Answer 2

嘗試在Java文件

requestWindowFeature(Window.FEATURE_CUSTOM_TITLE); 
    setContentView(R.layout.tabs); 
    getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.win_title); 

使用，使XML佈局這樣

<LinearLayout android:id="@+id/l1" android:layout_width="fill_parent" android:layout_height="fill_parent" 
        android:orientation="vertical" android:padding="5dp"> 

     <TabWidget android:id="@android:id/tabs" android:layout_width="fill_parent" android:layout_height="wrap_content" 
        android:scrollbars="horizontal"/> 

     <FrameLayout android:id="@android:id/tabcontent" android:layout_width="fill_parent" android:layout_height="fill_parent" 
        android:padding="5dp"/> 

    </LinearLayout> 

希望這將工作