MainActivity.java:
package com.app.loadermanager;
import java.util.ArrayList;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.LoaderManager;
import android.content.CursorLoader;
import android.content.Loader;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
@SuppressLint("NewApi")
public class MainActivity extends Activity implements
LoaderManager.LoaderCallbacks<Cursor> {
LoaderManager manager = null;
ListView listView = null;
@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) this.findViewById(R.id.listview);
manager = this.getLoaderManager();
manager.initLoader(1000, null, this);
}
@Override
public Loader<Cursor> onCreateLoader(int id, Bundle bundle) {
CursorLoader loader = new CursorLoader(this,
Uri.parse("content://com.app.contentprovider"), null, null,
null, null);
return loader;
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
ArrayList<String> al = new ArrayList<String>();
while (cursor.moveToNext()) {
String name = cursor.getString(cursor.getColumnIndex("name"));
al.add(name);
}
ArrayAdapter adapter=new ArrayAdapter(this,android.R.layout.simple_list_item_1,al);
listView.setAdapter(adapter);
adapter.notifyDataSetChanged();
}
@Override
public void onLoaderReset(Loader<Cursor> loader) {
}
}
LoaderManager与生命周期
Activity和Fragment都拥有getLoaderManager的方法，其实Fragment的getLoaderManager去获取的就是Activity所管理的众多LoaderManager之一。
1.Who标签
先来看一下Activity的getLoaderManager方法：
LoaderManagerImpl getLoaderManager(String who, boolean started, boolean create) {
if (mAllLoaderManagers == null) {
mAllLoaderManagers = new ArrayMap<String, LoaderManagerImpl>();
}
LoaderManagerImpl lm = mAllLoaderManagers.get(who);
if (lm == null) {
if (create) {
lm = new LoaderManagerImpl(who, this, started);
mAllLoaderManagers.put(who, lm);
}
} else {
lm.updateActivity(this);
}
return lm;
}
