SwipeRefreshLayout是Google在support v4 19.1版本的library更新的一个下拉刷新组件, 实现刷新效果更方便。使用Android官方自带的控件能够保证通用性以及风格。目前市面上很多app的下拉刷新组件就是用的它。但是这个组件只支持下拉刷新,不支持上拉加载更多的操作。
因此,我们来简单的看一下如何使用SwipeRefreshLayout 实现下拉刷新功能,然后我们再来添加上拉加载更多。上拉加载更多主要是通过监听ListView的滚动事件来实现的。
先看一下效果,还是很不错的。。
本文只是提供功能实现的示例,并没有对组件进行封装。
整个过程比较简单,直接上代码了。
首先,在xml文件中引用android.support.v4.widget.SwipeRefreshLayout控件。
main.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" >
<android.support.v4.widget.SwipeRefreshLayout
android:id="@+id/swipe"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<ListView
android:id="@+id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
</android.support.v4.widget.SwipeRefreshLayout>
</LinearLayout>
配置底部 加载更多布局
footer.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" >
<LinearLayout
android:id="@+id/footer_load"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="horizontal"
android:paddingBottom="10dip"
android:paddingTop="10dip" >
<ProgressBar
style="?android:attr/progressBarStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="正在加载..." />
</LinearLayout>
</LinearLayout>
示例ListView的item布局
item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:layout_centerInParent="true"
android:id="@+id/item_title"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="25sp"
android:textStyle="bold"/>
<TextView
android:id="@+id/item_content"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="15sp"
/>
</LinearLayout>
在Activity中实现
SwipeRefreshAndLoadActivity.java
package com.example.app;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.widget.SwipeRefreshLayout;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.HashMap;
/**
* Created by jorry on 2016/8/8.
*/
public class SwipeRefreshAndLoadActivity extends Activity implements AbsListView.OnScrollListener{
int totalItemCount;// 总数量;
int lastVisibleItem;// 最后一个可见的item;
boolean isLoading;// 正在加载
View footer;// 底部布局;
ArrayList<HashMap<String, Object>> listItem;
SimpleAdapter mSimpleAdapter;
SwipeRefreshLayout swipeRefreshLayout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LayoutInflater mLi = LayoutInflater.from(this);
swipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.swipe);
//设置下拉刷新 小圈圈颜色 ,最多可设置4个颜色
swipeRefreshLayout.setColorSchemeResources(R.color.dodgerblue, R.color.lawngreen, R.color.colorAccent, R.color.orange);
ListView lv = (ListView) findViewById(R.id.list);
//配置底部 加载更多 的布局
footer = mLi.inflate(R.layout.footer, null);
footer.findViewById(R.id.footer_load).setVisibility(View.VISIBLE);
lv.addFooterView(footer, null, false);
//模拟数据
listItem = new ArrayList<HashMap<String, Object>>();
for (int i = 0; i < 10; i++) {
HashMap<String, Object> map = new HashMap<String, Object>();
map.put("ItemTitle", "第" + i + "行");
map.put("ItemContent", "这是第" + i + "行");
listItem.add(map);
}
//构造适配器
mSimpleAdapter = new SimpleAdapter(this, listItem,
R.layout.item, new String[]{"ItemTitle", "ItemContent"},
new int[]{R.id.item_title, R.id.item_content}
);
lv.setAdapter(mSimpleAdapter);
//设置点击事件
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Toast.makeText(SwipeRefreshAndLoadActivity.this, listItem.get(i).get("ItemTitle").toString(), Toast.LENGTH_LONG).show();
}
});
//设置下拉刷新监听器
swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
doRefreshDatas();
swipeRefreshLayout.setRefreshing(false);
}
}, 2000);
}
});
//设置滚动事件监听, 实现 上拉加载更多
lv.setOnScrollListener(this);
}
@Override
public void onScrollStateChanged(AbsListView absListView, int scrollState) {
// System.out.println("hehe"+isLoading);
if (totalItemCount == lastVisibleItem&& scrollState == SCROLL_STATE_IDLE) {
if (!isLoading) {
isLoading = true;
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
// 加载更多
footer.findViewById(R.id.footer_load).setVisibility(View.VISIBLE);
doLoadMoreDatas();
isLoading = false;
}
}, 2000);
}
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
this.lastVisibleItem = firstVisibleItem + visibleItemCount;
this.totalItemCount = totalItemCount;
}
//刷新数据, 并通知adapter更新
public void doRefreshDatas(){
listItem.clear();
for (int i = 0; i < 10; i++) {
HashMap<String, Object> map = new HashMap<String, Object>();
map.put("ItemTitle", "第" + i + "行new");
map.put("ItemContent", "这是第" + i + "行new");
listItem.add(map);
}
mSimpleAdapter.notifyDataSetChanged();
}
//加载更多数据,并通知adapter更新
public void doLoadMoreDatas(){
int j =listItem.size()+10;
for (int i =listItem.size(); i<=j; i++){
HashMap<String, Object> map = new HashMap<String, Object>();
map.put("ItemTitle", "第" + i + "行");
map.put("ItemContent", "这是第" + i + "行");
listItem.add(map);
}
mSimpleAdapter.notifyDataSetChanged();
}
}
请尊重原创, 转载注明出处 http://blog.youkuaiyun.com/jorrytsai/article/details/52154197