如何在android的api 11+ Android版listview中显示联系人?

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据我所知,我已经按照教程进行了操作,没​​有任何联系人出现。我认为最重要的是它TO_IDS是一个指向的整数数组android.R.id.text1。我很困惑,这应该怎样拉取一组联系人姓名。

另外,我很困惑为什么当最终目标是显示一个列表视图时需要一个textview ...在教程中,我们有mContactsList这是一个列表视图...但是我们用一个指向R.layout.contact_list_item它的适配器填充列表视图只是由TO_IDS填充的textviews,整数数组:

mContactsList = (ListView) getActivity().findViewById(R.layout.contact_list_view);
mCursorAdapter = new SimpleCursorAdapter(
            getActivity(),
            R.layout.contact_list_item,
            null,
            FROM_COLUMNS, TO_IDS,
            0);
mContactList.setAdapter(mCursorAdapter);

在我的片段类中:

public class MyFragment extends Fragment implements
    LoaderManager.LoaderCallbacks<Cursor>{

private static final String[] FROM_COLUMNS = {ContactsContract.Contacts.DISPLAY_NAME_PRIMARY };
private static final int[] TO_IDS = {android.R.id.text1};
ListView mContactList;
private SimpleCursorAdapter mCursorAdapter;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
    return inflater.inflate(R.layout.contact_list_view,container,false);
}

@Override
public void onActivityCreated(Bundle savedInstanceState){
    super.onActivityCreated(savedInstanceState);
    mContactsList = (ListView) getActivity().findViewById(R.layout.contact_list_view);
    mCursorAdapter = new SimpleCursorAdapter(
            getActivity(),
            R.layout.contact_list_item,
            null,
            FROM_COLUMNS, TO_IDS,
            0);
    mContactList.setAdapter(mCursorAdapter);

}

@Override
public Loader<Cursor> onCreateLoader(int i, Bundle bundle) {
    return null;
}

@Override
public void onLoadFinished(Loader<Cursor> cursorLoader, Cursor cursor) {

}

@Override
public void onLoaderReset(Loader<Cursor> cursorLoader) {

}
}

在我的activity_main.xml中:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <fragment
            android:id ="@+id/contactListFragment"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:name="preamble.myapp.MyFragment"/>
</LinearLayout>

在我的contact_list_view xml中:

<?xml version="1.0" encoding="utf-8"?>
<ListView   xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@android:id/list"
            android:layout_height="match_parent"
            android:layout_width="match_parent"/>

在我的contact_list_item xml中:

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@android:id/text1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>

最后为contact_list_layout xml:

我放什么contact_list_layout.xml?这只是一个空的<LinearLayout>?在教程中不清楚这个xml是如何处理的。它说这个XML是片段,但如果它是片段,为什么我们listview已经定义了一个contact_list_view.xml

提问于
用户回答回答于

列表项的布局也取自Android的默认布局(android.R.layout.simple_list_item_1),这是每个项目简单的单行文本:

import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.ContactsContract.Contacts;
import android.support.v4.app.ListFragment;
import android.support.v4.app.LoaderManager.LoaderCallbacks;
import android.support.v4.content.CursorLoader;
import android.support.v4.content.Loader;
import android.support.v4.widget.CursorAdapter;
import android.support.v4.widget.SimpleCursorAdapter;

public class ContactListFragment extends ListFragment implements LoaderCallbacks<Cursor> {

    private CursorAdapter mAdapter;

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

        // create adapter once
        Context context = getActivity();
        int layout = android.R.layout.simple_list_item_1;
        Cursor c = null; // there is no cursor yet
        int flags = 0; // no auto-requery! Loader requeries.
        mAdapter = new SimpleCursorAdapter(context, layout, c, FROM, TO, flags);
    }

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

        // each time we are started use our listadapter
        setListAdapter(mAdapter);
        // and tell loader manager to start loading
        getLoaderManager().initLoader(0, null, this);
    }

    // columns requested from the database
    private static final String[] PROJECTION = {
        Contacts._ID, // _ID is always required
        Contacts.DISPLAY_NAME_PRIMARY // that's what we want to display
    };

    // and name should be displayed in the text1 textview in item layout
    private static final String[] FROM = { Contacts.DISPLAY_NAME_PRIMARY };
    private static final int[] TO = { android.R.id.text1 };

    @Override
    public Loader<Cursor> onCreateLoader(int id, Bundle args) {

        // load from the "Contacts table"
        Uri contentUri = Contacts.CONTENT_URI;

        // no sub-selection, no sort order, simply every row
        // projection says we want just the _id and the name column
        return new CursorLoader(getActivity(),
                contentUri,
                PROJECTION,
                null,
                null,
                null);
    }

    @Override
    public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
        // Once cursor is loaded, give it to adapter
        mAdapter.swapCursor(data);
    }

    @Override
    public void onLoaderReset(Loader<Cursor> loader) {
        // on reset take any old cursor away
        mAdapter.swapCursor(null);
    }
}

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