1.ListView分页的实现,重点在于实现OnScrollListener接口,判断滑动到最后一项时,是否还有数据可以加载,
我们可以利用listView.addFootView(View v)方法进行提示
自定义一个ListView(这里本来想进行一些自定已修改的。。。实际代码并没有做)CornerListView
package com.example.testlistview;import android.widget.AbsListView; import android.content.Context; import android.util.AttributeSet; import android.widget.ListView;public class CornerListView extends ListView{public CornerListView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);// TODO Auto-generated constructor stub }public CornerListView(Context context, AttributeSet attrs) {super(context, attrs);// TODO Auto-generated constructor stub }public CornerListView(Context context) {super(context);// TODO Auto-generated constructor stub } }
包含ListView的配置文件 activity_main.xml
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"android:paddingLeft="@dimen/activity_horizontal_margin"android:paddingRight="@dimen/activity_horizontal_margin"android:paddingTop="@dimen/activity_vertical_margin"tools:context="com.example.testlistview.MainActivity" ><com.example.testlistview.CornerListView android:layout_width="fill_parent"android:layout_height="fill_parent"android:layout_margin="10dip"android:id="@+id/list"></com.example.testlistview.CornerListView></RelativeLayout>
ListView每一项的Item配置文件 listview_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" ><TextViewandroid:id="@+id/tvTitle"android:layout_width="fill_parent"android:layout_height="wrap_content"android:text="1"android:gravity="center_horizontal"></TextView> </LinearLayout>
有更多数据时的配置文件more.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent" ><TextView android:id="@+id/tv_msg"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_centerInParent="true"android:text="更多"/><ProgressBar android:id="@+id/loading"style="@android:style/Widget.ProgressBar.Large"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_centerHorizontal="true"android:visibility="gone"/> </RelativeLayout>
CorernerListView对应的Adapter适配器 CornerAdapter.java
package com.example.testlistview;import java.util.List;import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.TextView;public class CornerAdapter extends BaseAdapter{LayoutInflater inflater;public List<String> list;private Context context;public CornerAdapter(List<String> list, Context context) {this.list = list;this.context = context;}@Overridepublic int getCount() {return list.size();}@Overridepublic Object getItem(int position) {return list.get(position);}@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {ViewHolder viewHolder;if(convertView == null){viewHolder = new ViewHolder();convertView = LayoutInflater.from(context).inflate(R.layout.listview_item, null, false);TextView tv1= (TextView) convertView.findViewById(R.id.tvTitle);viewHolder.tv = tv1;convertView.setTag(viewHolder);}else{viewHolder = (ViewHolder) convertView.getTag();}viewHolder.tv.setText(list.get(position));return convertView;}class ViewHolder{public TextView tv;} }
主Activity代码:
package com.example.testlistview;import java.util.ArrayList; import java.util.List;import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.AbsListView; import android.widget.AbsListView.OnScrollListener; import android.widget.TextView;public class MainActivity extends Activity implements OnScrollListener{private int pageIndex = 1;private int pageSize = 2;private int pageCount = 2;//初始设置页数为2,因为刚开始不知道总页数private CornerListView listView;private CornerAdapter adapter;private View footer,tvMsg,loading;private boolean is_divPage = false;//是否分页private List<String> list = new ArrayList<String>();@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);listView = (CornerListView) findViewById(R.id.list);listView.setOnScrollListener(this);footer = View.inflate(this, R.layout.more, null);tvMsg = footer.findViewById(R.id.tv_msg);loading = footer.findViewById(R.id.loading);listView.addFooterView(footer);//添加footerviewThread thread = new Thread(runnable);//第一次访问服务器接口,返回第一页信息,并确定总页数信息 thread.start();}//异步访问网络加载数据之类的。。Runnable runnable = new Runnable() {@Overridepublic void run() {//传递pageIndex,pageSize,URL等参数访问网络获取数据,这里省略。。。//doSomethingString strJson = "";//假定strJson就是服务器返回的这一页Json数据//假设这里返回总页数为5pageCount = 5;Message msg = new Message();msg.obj = strJson;handler.sendMessage(msg);//将消息返回给UI }};//处理返回的消息,设置ListViewHandler handler = new Handler(){@Overridepublic void handleMessage(Message msg) {String strJson = msg.obj.toString();//各种转换组合数据,这里我们就不做了,模拟一下数据for(int i=0;i<pageSize; ++i){if(adapter != null && adapter.list != null)//从获取第二页开始,直接修改适配器的list {adapter.list.add(i+"");}else//第一次适配器还没有构造 {list.add(i+"");}}if(pageIndex == 1)//第一次,设置适配器 {adapter = new CornerAdapter(list, MainActivity.this);listView.setAdapter(adapter);//判断一下是否显示更多按钮if(pageIndex == pageCount){listView.removeFooterView(footer);}else if(pageIndex < pageCount){//设置tvmsg显示,加载动画不显示 tvMsg.setVisibility(View.VISIBLE);loading.setVisibility(View.GONE);}}else{//直接调用方法更新数据 adapter.notifyDataSetChanged();if(pageIndex == pageCount){listView.removeFooterView(footer);}else if(pageIndex < pageCount){//设置tvmsg显示,加载动画不显示 tvMsg.setVisibility(View.VISIBLE);loading.setVisibility(View.GONE);}}}};@Overridepublic void onScrollStateChanged(AbsListView view, int scrollState) {//需要分页,触摸停止,当前确实还有分页数据if(is_divPage && scrollState == OnScrollListener.SCROLL_STATE_IDLE && pageIndex < pageCount){pageIndex += 1;//设置请求当前页码加1Thread thread = new Thread(runnable);thread.start();}}@Overridepublic void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {//现在 Bug初始情况下向下滑动也能翻页int lastVisibleItem = firstVisibleItem + visibleItemCount;//当前滑动到最后一项if(lastVisibleItem == totalItemCount && totalItemCount > 0){is_divPage = true;}} }