Android 我无法将我的活动扩展到listactivity

需要帮助。我得到的错误与前面的相同：（

在XML中，确保您有一个具有android ID的

列表视图，如下所示：

而不是您的XML：
>您的内容必须有一个id属性为“android.R.id.list”的列表视图。您需要使用
android:id=“@+id/list”
我的xml文件在
activity\u main.xml
中添加列表视图。。。
public class MainActivity extends ListActivity implements OnItemClickListener {
// private ListView lView;
 private ArrayList results = new ArrayList();
 PackageInfo pInfo;
 String packageName;
 String app;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
//  lView= findViewById(R.id.list);
    PackageManager pm = this.getPackageManager();
    Intent intent = new Intent(Intent.ACTION_MAIN, null);
    intent.addCategory(Intent.CATEGORY_LAUNCHER);
    List < ResolveInfo > list = pm.queryIntentActivities(intent, PackageManager.PERMISSION_GRANTED);
    for (ResolveInfo rInfo: list) {
        results.add(rInfo.activityInfo.applicationInfo
            .loadLabel(pm).toString());
        Log.w("Installed Applications", rInfo.activityInfo.applicationInfo
            .loadLabel(pm).toString());
    }
            getListView().setOnItemClickListener(this);
            setListAdapter(new ArrayAdapter(this, android.R.layout.simple_list_item_1, results));
}


 @Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
    pInfo= (PackageInfo) results.get(arg2);
    app= (String) results.get(arg2);
    packageName = pInfo .packageName;
    try {
        Class myapp= Class.forName(packageName + app);
        Intent myintent= new Intent(MainActivity.this, myapp);
        startActivity(myintent);
    } catch (ClassNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}
}

05-15 17:19:52.383: E/AndroidRuntime(6370): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ku.installedapps/com.ku.installedapps.MainActivity}: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'

<ListView android:id="@android:id/list" ...>