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我有一个应用程序，ActionBarActivity里面有两个片段，代表每个选项卡......问题是我在片段1上有一个列表，有两个值“teste”和“teste2”但是当我更改为片段2（tab2）并返回再次到 tab1 它会重复列表中的值，例如 "teste","teste2", "teste" , "teste2" 我怎样才能防止这种情况发生？

TabActionBarActivity：

public class TabActionBarActivity extends Activity {

String contextoId;
String BuId;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_tab_action_bar);

    ActionBar actionBar = getActionBar();
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    String label1 = getResources().getString(R.string.label1);
    Tab tab = actionBar.newTab();
    tab.setText(label1);

    TabListener<Tab1Fragment> tl = new TabListener<Tab1Fragment>(this, label1, Tab1Fragment.class);

   tab.setTabListener(tl);
    actionBar.addTab(tab);


    String label2 = getResources().getString(R.string.label2);
            tab = actionBar.newTab();
            tab.setText(label2);
            TabListener<Tab2Fragment> tl2 = new TabListener<Tab2Fragment>(this, label2, Tab2Fragment.class);
            tab.setTabListener(tl2);
            actionBar.addTab(tab);


            BuId =  getIntent().getExtras().getString("BUId");
            contextoId = getIntent().getExtras().getString("CId");
            Log.i("BUIdTabFrag", BuId);



}


private class TabListener<T extends Fragment> implements
            ActionBar.TabListener {
        private Fragment mFragment;
        private final Activity mActivity;
        private final String mTag;
        private final Class<T> mClass;


        public TabListener(Activity activity, String tag, Class<T> clz) {
                        mActivity = activity;
                        mTag = tag;
                        mClass = clz;
                    }



        @Override
        public void onTabReselected(Tab tab, FragmentTransaction ft) {
            // TODO Auto-generated method stub

        }




        @Override
        public void onTabSelected(Tab tab, FragmentTransaction ft) {
             // Check if the fragment is already initialized
                        if (mFragment == null) {
                            // If not, instantiate and add it to the activity
                            mFragment = Fragment.instantiate(mActivity, mClass.getName());
                            ft.add(android.R.id.content, mFragment, mTag);
                        } else {
                            // If it exists, simply attach it in order to show it
                            ft.attach(mFragment);
                        }


        }




        @Override
        public void onTabUnselected(Tab tab, FragmentTransaction ft) {
             if (mFragment != null) {
                                 // Detach the fragment, because another one is being attached
                                 ft.detach(mFragment);
                             }


        }




}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.tab_action_bar, menu);
    return true;
}

希望你能帮我

“编辑”

如果我这样做：

ft.replace(android.R.id.content, mFragment, mTag).commit();

它给了我一个错误：

log: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.icenterv2/com.example.admin.TabActionBarActivity}: java.lang.IllegalStateException: commit already called

在这条线上：actionBar.addTab(tab);

和

ft.replace(android.R.id.content, mFragment, mTag);

这样它再次复制

4

1 回答 1

0

问题不在于您的ListView代码，而在于ActionBar您的 MainActivity 中的代码。您没有正确连接、分离和更换您的fragments. 我有同样的问题。发布您的 MainActivity 的代码，我可以帮助您

你需要更换

ft.add(android.R.id.content, mFragment, mTag);

和

ft.replace(android.R.id.content, mFragment, mTag).commit();

所以你里面的方法onTabSelected(Tab tab, FragmentTransaction ft)应该是这样的

 public void onTabSelected(Tab tab, FragmentTransaction ft) {
         // Check if the fragment is already initialized
                    if (mFragment == null) {
                        // If not, instantiate and add it to the activity
                        mFragment = Fragment.instantiate(mActivity, mClass.getName());
                        ft.replace(android.R.id.content, mFragment, mTag);
                    } else {
                        // If it exists, simply attach it in order to show it
                        ft.attach(mFragment);
                    }


    }

因为截至目前它正在“添加”fragment到容器中，给你重复。

于 2013-06-06T16:47:06.110 回答