listView的分页滑动 - xuan轩

1. ListView分页加载实现思路

实现OnScrollListener 接口重写onScrollStateChanged 和onScroll方法，使用onscroll方法实现”滑动“后处理检查是否还有新的记录，如果有，调用 addFooterView，添加记录到adapter, adapter调用 notifyDataSetChanged 更新数据;如果没有记录了，把自定义的mFooterView去掉。使用onScrollStateChanged可以检测是否滚到最后一行且停止滚动然后执行加载。

 1 [java] view plaincopyprint?
 2 import android.app.ListActivity;  
 3 import android.os.Bundle;  
 4 import android.os.Handler;  
 5 import android.view.Gravity;  
 6 import android.view.View;  
 7 import android.view.ViewGroup;  
 8 import android.widget.AbsListView;  
 9 import android.widget.BaseAdapter;  
10 import android.widget.ImageView;  
11 import android.widget.LinearLayout;  
12 import android.widget.ProgressBar;  
13 import android.widget.TextView;  
14 import android.widget.AbsListView.OnScrollListener;  
15 import android.widget.LinearLayout.LayoutParams;  
16 public class Test extends ListActivity implements OnScrollListener {  
17     Aleph0 adapter = new Aleph0();  
18     int lastItem = 0;  
19     int mProgressStatus = 0;  
20     private Handler mHandler = new Handler();  
21     ProgressBar progressBar;  
22     protected void onCreate(Bundle savedInstanceState) {  
23         super.onCreate(savedInstanceState);  
24    LinearLayout searchLayout = new LinearLayout(this);  
25    searchLayout.setOrientation(LinearLayout.HORIZONTAL);  
26          progressBar = new ProgressBar(this);  
27          progressBar.setPadding(0, 0, 15, 0);  
28          searchLayout.addView(progressBar,new LinearLayout.LayoutParams(  
29            LinearLayout.LayoutParams.WRAP_CONTENT,  
30            LinearLayout.LayoutParams.WRAP_CONTENT  
31          ));  
32          TextView textView = new TextView(this);  
33          textView.setText("加载中...");  
34          textView.setGravity(Gravity.CENTER_VERTICAL);  
35          searchLayout.addView(textView,new LinearLayout.LayoutParams(  
36            LinearLayout.LayoutParams.FILL_PARENT,  
37            LinearLayout.LayoutParams.FILL_PARENT  
38          ));  
39          searchLayout.setGravity(Gravity.CENTER);  
40          LinearLayout loadingLayout = new LinearLayout(this);  
41          loadingLayout.addView(searchLayout,new LinearLayout.LayoutParams(  
42            LinearLayout.LayoutParams.WRAP_CONTENT,  
43            LinearLayout.LayoutParams.WRAP_CONTENT  
44          ));  
45          loadingLayout.setGravity(Gravity.CENTER);  
46         getListView().addFooterView(loadingLayout);  
47         // Start lengthy operation in a background thread  
48 //        new Thread(new Runnable() {  
49 //            public void run() {  
50 //                while (mProgressStatus < 100) {  
51 //  
52 //                    // Update the progress bar  
53 //                    mHandler.post(new Runnable() {  
54 //                        public void run() {  
55 //                        progressBar.setProgress(mProgressStatus);  
56 //                        }  
57 //                    });  
58 //                }  
59 //            }  
60 //        }).start();  
61         registerForContextMenu(getListView());  
62         setListAdapter(adapter);  
63         getListView().setOnScrollListener(this);  
64     }  
65     public void onScroll(AbsListView v, int firstVisibleItem, int visibleItemCount, int totalItemCount) {   
66         lastItem = firstVisibleItem + visibleItemCount - 1 ;  
67         System.out.println("lastItem:" + lastItem);  
68     }  
69     public void onScrollStateChanged(AbsListView v, int state) {  
70     if(lastItem == adapter.count && state == OnScrollListener.SCROLL_STATE_IDLE){  
71           adapter.count += 10;  
72           adapter.notifyDataSetChanged();  
73     }  
74 //        if(state == OnScrollListener.SCROLL_STATE_IDLE ) {  
75 //                adapter.count += 10;  
76 //                adapter.notifyDataSetChanged();  
77 //        }  
78     }  
79     class Aleph0 extends BaseAdapter {  
80         int count = 10;  
81         public int getCount() { return count; }  
82         public Object getItem(int pos) { return pos; }  
83         public long getItemId(int pos) { return pos; }  
84         public View getView(int pos, View v, ViewGroup p) {  
85                 TextView view = new TextView(Test.this);  
86                 view.setText("entry " + pos);  
87                 view.setHeight(90);  
88                 return view;  
89         }  
90     }  
91 }

第二种。

  1 package com.notice.moredate;
  2 
  3 import java.util.ArrayList;
  4 import java.util.HashMap;
  5 
  6 import android.app.Activity;
  7 import android.os.Bundle;
  8 import android.os.Handler;
  9 import android.view.View;
 10 import android.view.View.OnClickListener;
 11 import android.widget.AbsListView;
 12 import android.widget.AbsListView.OnScrollListener;
 13 import android.widget.Button;
 14 import android.widget.ListView;
 15 import android.widget.ProgressBar;
 16 import android.widget.SimpleAdapter;
 17 import android.widget.Toast;
 18 
 19 public class MoreDateListActivity extends Activity implements OnScrollListener {
 20     
 21     // ListView的Adapter
 22     private SimpleAdapter mSimpleAdapter;
 23     private ListView lv;
 24     private Button bt;
 25     private ProgressBar pg;
 26     private ArrayList<HashMap<String,String>> list;
 27     // ListView底部View
 28     private View moreView;
 29     private Handler handler;
 30     // 设置一个最大的数据条数，超过即不再加载
 31     private int MaxDateNum;
 32     // 最后可见条目的索引
 33     private int lastVisibleIndex;
 34     
 35     /** Called when the activity is first created. */
 36     @Override
 37     public void onCreate(Bundle savedInstanceState) {
 38         super.onCreate(savedInstanceState);
 39         setContentView(R.layout.main);
 40         
 41         
 42         MaxDateNum = 22; // 设置最大数据条数
 43 
 44         lv = (ListView) findViewById(R.id.lv);
 45 
 46         // 实例化底部布局
 47         moreView = getLayoutInflater().inflate(R.layout.moredate, null);
 48 
 49         bt = (Button) moreView.findViewById(R.id.bt_load);
 50         pg = (ProgressBar) moreView.findViewById(R.id.pg);
 51         handler = new Handler();
 52 
 53         // 用map来装载数据，初始化10条数据
 54         list = new ArrayList<HashMap<String,String>>();
 55         for (int i = 0; i < 10; i++) {
 56             HashMap<String, String> map = new HashMap<String, String>();
 57             map.put("ItemTitle", "第" + i + "行标题");
 58             map.put("ItemText", "第" + i + "行内容");
 59             list.add(map);
 60         }
 61         // 实例化SimpleAdapter
 62         mSimpleAdapter = new SimpleAdapter(this, list, R.layout.item,
 63                 new String[] { "ItemTitle", "ItemText" },
 64                 new int[] { R.id.tv_title, R.id.tv_content });
 65         // 加上底部View，注意要放在setAdapter方法前
 66         lv.addFooterView(moreView);
 67         lv.setAdapter(mSimpleAdapter);
 68         // 绑定监听器
 69         lv.setOnScrollListener(this);
 70 
 71         bt.setOnClickListener(new OnClickListener() {
 72 
 73             @Override
 74             public void onClick(View v) {
 75                 pg.setVisibility(View.VISIBLE);// 将进度条可见
 76                 bt.setVisibility(View.GONE);// 按钮不可见
 77 
 78                 handler.postDelayed(new Runnable() {
 79 
 80                     @Override
 81                     public void run() {
 82                         loadMoreDate();// 加载更多数据
 83                         bt.setVisibility(View.VISIBLE);
 84                         pg.setVisibility(View.GONE);
 85                         mSimpleAdapter.notifyDataSetChanged();// 通知listView刷新数据
 86                     }
 87 
 88                 }, 2000);
 89             }
 90         });
 91 
 92     }
 93 
 94     private void loadMoreDate() {
 95         int count = mSimpleAdapter.getCount();
 96         if (count + 5 < MaxDateNum) {
 97             // 每次加载5条
 98             for (int i = count; i < count + 5; i++) {
 99                 HashMap<String, String> map = new HashMap<String, String>();
100                 map.put("ItemTitle", "新增第" + i + "行标题");
101                 map.put("ItemText", "新增第" + i + "行内容");
102                 list.add(map);
103             }
104         } else {
105             // 数据已经不足5条
106             for (int i = count; i < MaxDateNum; i++) {
107                 HashMap<String, String> map = new HashMap<String, String>();
108                 map.put("ItemTitle", "新增第" + i + "行标题");
109                 map.put("ItemText", "新增第" + i + "行内容");
110                 list.add(map);
111             }
112         }
113 
114     }
115 
116     @Override
117     public void onScroll(AbsListView view, int firstVisibleItem,
118             int visibleItemCount, int totalItemCount) {
119         // 计算最后可见条目的索引
120         lastVisibleIndex = firstVisibleItem + visibleItemCount - 1;
121 
122         // 所有的条目已经和最大条数相等，则移除底部的View
123         if (totalItemCount == MaxDateNum + 1) {
124             lv.removeFooterView(moreView);
125             Toast.makeText(this, "数据全部加载完成，没有更多数据！", Toast.LENGTH_LONG).show();
126         }
127 
128     }
129 
130     @Override
131     public void onScrollStateChanged(AbsListView view, int scrollState) {
132         // 滑到底部后自动加载，判断listview已经停止滚动并且最后可视的条目等于adapter的条目
133         if (scrollState == OnScrollListener.SCROLL_STATE_IDLE
134                 && lastVisibleIndex == mSimpleAdapter.getCount()) {
135             // 当滑到底部时自动加载
136             // pg.setVisibility(View.VISIBLE);
137             // bt.setVisibility(View.GONE);
138             // handler.postDelayed(new Runnable() {
139             //
140             // @Override
141             // public void run() {
142             // loadMoreDate();
143             // bt.setVisibility(View.VISIBLE);
144             // pg.setVisibility(View.GONE);
145             // mSimpleAdapter.notifyDataSetChanged();
146             // }
147             //
148             // }, 2000);
149 
150         }
151 
152     }
153     
154 }

posted on 2014-09-26 11:46 xuan轩阅读(770) 评论(0) 编辑收藏举报

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