Android PullToRefresh——ListView使用详解

前段时间，在使用ListView的过程中突然发现PullToRefresh的使用方法，用于上拉下拉刷新使用，觉得该方法很好使用，特此分享，供大家参考。

由于PullToRefresh方法是开源的第三方插件使用，所以使用步骤如下：

1、在GitHub上面下载源码以及需使用的包，地址为https://github.com/chrisbanes/Android-PullToRefresh，将library文件夹引用至自己的工作项目。（再此不做详细的导入说明）

2、导入完成之后，就可以开始编写自己的xml文件，具体代码如下。

注意：为了使用PullToRefresh一些属性，需要引命名空间，因此

xmlns:ptr = "http://schemas.android.com/apk/res-auto"
ptr:ptrMode="both"

该两行代码不能省略。

<LinearLayout 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:orientation="vertical"
android:background="@color/bg"
tools:context=".MainActivity">

<com.handmark.pulltorefresh.library.PullToRefreshListView
xmlns:ptr = "http://schemas.android.com/apk/res-auto"
android:id="@+id/pull_refresh_list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:dividerHeight="1dp"
android:fadingEdge="none"
android:fastScrollEnabled="false"
android:footerDividersEnabled="false"
android:headerDividersEnabled="false"
android:smoothScrollbar="true"
android:focusableInTouchMode="true"
android:focusable="true"
ptr:ptrMode="both"/>

</LinearLayout>

3、编写java文件，具体代码如下。

package pulltorefresh.pulltorefresh;

import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemLongClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import com.handmark.pulltorefresh.library.PullToRefreshBase;
import com.handmark.pulltorefresh.library.PullToRefreshBase.OnRefreshListener2;
import com.handmark.pulltorefresh.library.PullToRefreshListView;

import java.util.Arrays;
import java.util.LinkedList;

/**
* PullToRefresh
* write by jimmy.li
* 2016/4/9  22:58
*/

public class MainActivity extends Activity {

private LinkedList<String> mListItems;
private PullToRefreshListView mPullRefreshListView;
private ArrayAdapter<String> mAdapter;

private int mDowmAddNum = 1;
private int mUpAddNum = 1;

//每次刷新增加5个listItem
private int mAddFalg = 5;

//数据源
private String[] mStrings = {"Jimmy1", "Jimmy2", "Jimmy3", "Jimmy4", "Jimmy5",
"Jimmy6", "Jimmy7", "Jimmy8", "Jimmy9", "Jimmy10", "Jimmy11", "Jimmy12",
"Jimmy13", "Jimmy14", "Jimmy15", "Jimmy16", "Jimmy17", "Jimmy18", "Jimmy19",
"Jimmy20", "Jimmy21", "Jimmy22", "Jimmy23", "Jimmy24", "Jimmy25", "Jimmy26"};

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

initUI();
initData();

}

private void initData() {
/**
* 实现 接口  OnRefreshListener2<ListView>  以便与监听  滚动条到顶部和到底部
*/
mPullRefreshListView.setOnRefreshListener(new OnRefreshListener2<ListView>() {
//onPullDownToRefresh
@Override
public void onPullDownToRefresh(PullToRefreshBase<ListView> refreshView) {
Toast.makeText(MainActivity.this, "onPullDownToRefresh", Toast.LENGTH_SHORT).show();
for (int i = 1; i <= mAddFalg; i++) {
mListItems.addFirst("Added Later refresh..." + mDowmAddNum);
mDowmAddNum++;
}
new GetDataTask().execute();
}

//onPullUpToRefresh
@Override
public void onPullUpToRefresh(PullToRefreshBase<ListView> refreshView) {
Toast.makeText(MainActivity.this, "onPullUpToRefresh", Toast.LENGTH_SHORT).show();
for (int i = 1; i <= mAddFalg; i++) {
mListItems.addLast("Added after refresh..." + mUpAddNum);
mUpAddNum++;
}

new GetDataTask().execute();
}
});

//获取控件并注册
ListView actualListView = mPullRefreshListView.getRefreshableView();

registerForContextMenu(actualListView);

mListItems = new LinkedList<String>();
mListItems.addAll(Arrays.asList(mStrings));

//设置适配器
mAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mListItems);
actualListView.setAdapter(mAdapter);
}

private void initUI() {
mPullRefreshListView = (PullToRefreshListView) findViewById(R.id.pull_refresh_list);
}

//模拟网络加载数据的   异步请求类
//
private class GetDataTask extends AsyncTask<Void, Void, String[]> {

//子线程请求数据
@Override
protected String[] doInBackground(Void... params) {
// Simulates a background job.
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
return mStrings;
}

//主线程更新UI
@Override
protected void onPostExecute(String[] result) {
mAdapter.notifyDataSetChanged();

// Call onRefreshComplete when the list has been refreshed.
mPullRefreshListView.onRefreshComplete();
super.onPostExecute(result);
}
}
}

4、主要代码讲解。

private void initData() {
/**
* 实现 接口  OnRefreshListener2<ListView>  以便与监听  滚动条到顶部和到底部
*/
mPullRefreshListView.setOnRefreshListener(new OnRefreshListener2<ListView>() {
//onPullDownToRefresh
@Override
public void onPullDownToRefresh(PullToRefreshBase<ListView> refreshView) {
Toast.makeText(MainActivity.this, "onPullDownToRefresh", Toast.LENGTH_SHORT).show();
for (int i = 1; i <= mAddFalg; i++) {
mListItems.addFirst("Added Later refresh..." + mDowmAddNum);
mDowmAddNum++;
}
new GetDataTask().execute();
}

//onPullUpToRefresh
@Override
public void onPullUpToRefresh(PullToRefreshBase<ListView> refreshView) {
Toast.makeText(MainActivity.this, "onPullUpToRefresh", Toast.LENGTH_SHORT).show();
for (int i = 1; i <= mAddFalg; i++) {
mListItems.addLast("Added after refresh..." + mUpAddNum);
mUpAddNum++;
}

new GetDataTask().execute();
}
});

上面主要是利用initData()函数将PullToRefresh上拉下拉刷新的主要代码封装起来，分别对应其下拉和上拉事件监听器。

//获取控件并注册
ListView actualListView = mPullRefreshListView.getRefreshableView();

registerForContextMenu(actualListView);

mListItems = new LinkedList<String>();
mListItems.addAll(Arrays.asList(mStrings));

//设置适配器
mAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mListItems);
actualListView.setAdapter(mAdapter);

上面代码主要是获取ListView空间并实行注册，并设置适配器以显示ListView。

Good luck!

Write by Jimmy.li