Android开发之ListFragment结合LoaderManager加载数据

之前实现过Android开发之ContentProvider结合LoaderManager加载数据，现在来实现用ListFragment加载
先看main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/LinearLayout1"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.listfragmentloadermanager.MainActivity" >    <LinearLayout        android:id="@+id/left"        android:layout_width="0sp"        android:layout_weight="1"        android:layout_height="match_parent"        android:orientation="vertical" >        <EditText            android:id="@+id/editText1"            android:layout_width="match_parent"            android:layout_height="wrap_content" >            <requestFocus />        </EditText>        <Button            android:id="@+id/button1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="添加姓名" />    </LinearLayout>    <LinearLayout        android:id="@+id/right"        android:layout_width="0sp"        android:layout_weight="2"        android:layout_height="match_parent"        android:orientation="vertical" >    </LinearLayout></LinearLayout>

说明：右边的linearlayout是要加载listFragment的子类的，通过“添加”按钮实现
由于是listFragment的子类，所以还是需要布局文件的（就是listfragment的默认布局）
list.xml

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

这里我们把listview每一项的item也自定义，就用最简单的textview
item.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical" >    <TextView        android:id="@+id/textView1"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="TextView" /></LinearLayout>

讲完了布局，我们来谈谈MainActivity.java和RightFragment.java
MainActivity.java

package com.example.listfragmentloadermanager;import android.app.Activity;import android.app.FragmentTransaction;import android.content.ContentResolver;import android.content.ContentValues;import android.net.Uri;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;public class MainActivity extends Activity {    private Button button;    private EditText editText;    private FragmentTransaction transaction;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        //加载listfragment        transaction = getFragmentManager().beginTransaction();        RightFragment rightFragment = new RightFragment();        transaction.replace(R.id.right, rightFragment);        transaction.commit();        editText = (EditText)findViewById(R.id.editText1);        button = (Button)findViewById(R.id.button1);        button.setOnClickListener(new OnClickListener(){            @Override            public void onClick(View v) {                String name = editText.getText().toString();                ContentResolver resolver = getContentResolver();                Uri uri = Uri.parse("content://com.example.loadermanagertest2." +                        "PersonContentProvider/person");                ContentValues values = new ContentValues();                values.put("name", name);                resolver.insert(uri, values);            }        });    }}

为什么这里不需要初始化LoaderManager呢？因为LoaderManager监听的是listview和contentprovider的数据变化。而这个例子的listview在listfragment里面，所以要挪到listfragment里面初始化
RightFragment.java：

package com.example.listfragmentloadermanager;import java.util.ArrayList;import java.util.List;import android.app.ListFragment;import android.app.LoaderManager;import android.app.LoaderManager.LoaderCallbacks;import android.content.CursorLoader;import android.content.Loader;import android.database.Cursor;import android.net.Uri;import android.os.Bundle;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.TextView;public class RightFragment extends ListFragment implements LoaderCallbacks<Cursor>{    private LoaderManager loaderManager;    private MyAdapter adapter;    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container,            Bundle savedInstanceState) {        loaderManager.initLoader(0, null, this);        View view = inflater.inflate(R.layout.list, null);        return view;    }    //onCreate里面初始化一些参数，而onCreateView里面创建布局    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        loaderManager = getLoaderManager();    }    @Override    public Loader<Cursor> onCreateLoader(int id, Bundle args) {        Uri uri = Uri.parse("content://com.example.loadermanagertest2." +                "PersonContentProvider/person");        CursorLoader loader = new CursorLoader(getActivity(), uri,                 null, null, null, null);        return loader;    }    @Override    public void onLoadFinished(Loader<Cursor> loader, Cursor data) {        List<String> list = new ArrayList<String>();        while (data.moveToNext()) {            list.add(data.getString(data.getColumnIndex("name")));        }        adapter = new MyAdapter();        adapter.bindData(list);        setListAdapter(adapter);        adapter.notifyDataSetChanged();    }    @Override    public void onLoaderReset(Loader<Cursor> loader) {    }    //自定义adapter取数据    class MyAdapter extends BaseAdapter {        private List<String> list;        public void bindData(List<String> list) {            this.list = list;        }        @Override        public int getCount() {            return list.size();        }        @Override        public Object getItem(int position) {            return list.get(position);        }        @Override        public long getItemId(int position) {            return position;        }        @Override        public View getView(int position, View convertView, ViewGroup parent) {            View view = null;            if (convertView == null) {                view = LayoutInflater.from(getActivity()).inflate(                        R.layout.item, null);            } else {                view = (View) convertView;            }            TextView textView = (TextView) view.findViewById(R.id.textView1);            textView.setText(list.get(position).toString());            return view;        }    }}

接下来就是实验结果

当然，com.example.loadermanagertest2.PersonContentProvider也就是上一篇这里写链接内容提到的manifest清单文件android:exported=”true”才行