ListFragment 指定的child已经有一个parent

Question

在我的应用程序中，我有一个带 ViewPagerAdapter 的选项卡式布局（4 个选项卡），用于从一个选项卡切换到另一个选项卡，在我实现 ListFragment 的所有选项卡中，因为我需要从 SQLite 加载数据并显示行.行已加载，但当我尝试切换到另一个选项卡时，应用程序崩溃并显示以下消息：

java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.

所以我搜索了这个错误，并找到了如下解决方案：

v = inflater.inflate(R.layout.tab_1_list, container, false);
v = inflater.inflate(R.layout.tab_1_list, null);

但是不行，错误还是一样

ViewPagerAdapter

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.content.Context;

public class ViewPagerAdapter extends FragmentStatePagerAdapter {

CharSequence Titles[]; // This will Store the Titles of the Tabs which are Going to be passed when ViewPagerAdapter is created
int NumbOfTabs; // Store the number of tabs, this will also be passed when the ViewPagerAdapter is created
private Context context;

// Build a Constructor and assign the passed Values to appropriate values in the class
public ViewPagerAdapter(FragmentManager fm,CharSequence mTitles[], int mNumbOfTabsumb) {
    super(fm);

    this.Titles = mTitles;
    this.NumbOfTabs = mNumbOfTabsumb;

}

//This method return the fragment for the every position in the View Pager
@Override
public Fragment getItem(int position) {

    if(position == 0) // if the position is 0 we are returning the First tab
    {
        Tab1 tab1 = new Tab1();
        return tab1;
    } else if(position == 1){
        Tab2 tab2 = new Tab2();
        return tab2;
    } else if(position == 2) {
        Tab3 tab3 = new Tab3(); 
        return tab3;    
    } else if(position == 3) {
        Tab4 tab4 = new Tab4();
        return tab4;
    } else {
        Tab1 tab1 = new Tab1();
        return tab1;
    }
}

// This method return the titles for the Tabs in the Tab Strip

@Override
public CharSequence getPageTitle(int position) {

    return Titles[position];
}

// This method return the Number of tabs for the tabs Strip

@Override
public int getCount() {
    return NumbOfTabs;
}
}

Tab1.java

public class Tab1 extends ListFragment
{

public View v;
public String title;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    v = inflater.inflate(R.layout.tab_1_list, container, false);

    //database handler
    DatabaseNumbersHandler db = new DatabaseNumbersHandler(getContext());
    ///get titles
    ArrayList list = db.getTitles();

    // Get a handle to the list view
    ListView lv = (ListView) v.findViewById(android.R.id.list);

    // Convert ArrayList to array
    String[] lv_arr = (String[]) list.toArray(new String[list.size()]);
    lv.setAdapter(new ArrayAdapter(getContext(), android.R.layout.simple_list_item_1, lv_arr));

    return lv;
}

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

    //
    // insert code here to setup and call setListAdapter()
    //
    //database handler

}

@Override
public void onListItemClick(ListView lv, View v, int position, long id)
{

}
}

tab_1_list.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="com.tyr.MainSettings">

<ListView
    android:id="@android:id/list"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
</ListView>

</RelativeLayout>

Answer 1

您返回 ListView 而不是 View

替换

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        v = inflater.inflate(R.layout.tab_1_list, container, false);

        //database handler
        DatabaseNumbersHandler db = new DatabaseNumbersHandler(getContext());
        ///get titles
        ArrayList list = db.getTitles();

        // Get a handle to the list view
        ListView lv = (ListView) v.findViewById(android.R.id.list);

        // Convert ArrayList to array
        String[] lv_arr = (String[]) list.toArray(new String[list.size()]);
        lv.setAdapter(new ArrayAdapter(getContext(), android.R.layout.simple_list_item_1, lv_arr));

        return v;
    }

ListFragment 指定的child已经有一个parent

ListFragment The specified child already has a parent

android

android-listfragment