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更新

我的xml文件和我的AsyncTask有问题。我的问题是我的代码上没有出现错误错误是

java.lang.RuntimeException: Unable to start activity    ComponentInfo{com.example.News/startPakage.tabs}: java.lang.RuntimeException: Your content must have a TabHost whose id attribute is 'android.R.id.tabhost'

我的代码是：

    private class GetDataTask extends AsyncTask<Void, Void, Integer> {
    Context     context;

    GetDataTask(Context context){this.context=context;}
    protected Integer doInBackground(Void... params) {

          int waited = 0;
          while (waited < 5000) {
          try {
            this.wait(100);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
             waited += 100;
          }
            return 1;
    }

    protected void onPostExecute(Integer result) {
        tabs.this.setContentView(R.layout.tabs);
      //setContentView(R.layout.tabs);

        TabHost tabHost= (TabHost)tabs.this.findViewById( android.R.id.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(context,start.class);

        // Initialize a TabSpec for each tab and add it to the TabHost
        spec = tabHost.newTabSpec("Heb news").setIndicator("Heb news").setContent(intent);
        tabHost.addTab(spec);

        // Do the same for the other tabs
        intent = new Intent().setClass(context, rusNewsP.ListRusNews.class);

        spec = tabHost.newTabSpec("Rus News").setIndicator("Rus News").setContent(intent);
        tabHost.addTab(spec);
        tabHost.setCurrentTab(0);
    }
}

我的xml是：

  <?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">
    <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>

如何修复我的代码呢？此代码用于在应用开始之前显示徽标。

Answer 1

this中的

onPostExecute表示AsyncTask类型的对象。如果您在地方创建AsyncTask，则必须使用this作为外部类型，如下所示：

class MyActivity : extends Activity {
  // ...

  void foo() {
    my asyncTask = new AsyncTask<Void, Void, Int >() {
      // ...

      protected void onPostExecute(Integer result) {
        MyActivity.this.setContentView(R.layout.tabs);
        tabs = (TabHost) MyActivity.this.findViewById( android.R.id.tabhost );
      }
    };
    asyncTask.execute();
  }
};

用AsyncTask在android上找不到ViewById

1 个答案: