下拉刷新原理。，下拉刷新原理

下拉刷新原理。，下拉刷新原理

 1 package com.lixu.listviewrefresh;
 2 
 3 import java.util.ArrayList;
 4 
 5 import android.app.Activity;
 6 import android.os.Bundle;
 7 import android.widget.AbsListView;
 8 import android.widget.AbsListView.OnScrollListener;
 9 import android.widget.ArrayAdapter;
10 import android.widget.ListView;
11 
12 public class MainActivity extends Activity {
13     private ArrayList<String> data;
14     private ArrayAdapter<String> mMyAdapter;
15 
16     @Override
17     protected void onCreate(Bundle savedInstanceState) {
18         super.onCreate(savedInstanceState);
19         setContentView(R.layout.activity_main);
20 
21         data = new ArrayList<String>();
22 
23         for (int i = 0; i < 30; i++) {
24             data.add("測試數據" + i);
25         }
26 
27         ListView lv = (ListView) findViewById(R.id.listview);
28 
29         mMyAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, data);
30 
31         lv.setAdapter(mMyAdapter);
32 
33         lv.setOnScrollListener(new OnScrollListener() {
34             private int firstVisibleItem;
35             private int visibleItemCount;
36             private int totalItemCount;
37 
38             @Override
39             public void onScrollStateChanged(AbsListView view, int scrollState) {
40                 // 當滑動停止的時候判斷
41                 if (OnScrollListener.SCROLL_STATE_IDLE == scrollState) {
42 
43                     if (firstVisibleItem == 0) {
44 
45                         data.add(0, "增加頭部數據" + (totalItemCount + 1));
46 
47                         mMyAdapter.notifyDataSetChanged();
48 
49                     }
50                 }
51 
52                 if (OnScrollListener.SCROLL_STATE_IDLE == scrollState) {
53 
54                     if ((firstVisibleItem + visibleItemCount) == totalItemCount) {
55 
56                         data.add("增加尾部數據" + (totalItemCount + 1));
57 
58                         mMyAdapter.notifyDataSetChanged();
59 
60                     }
61                 }
62 
63             }
64 
65             @Override
66             public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
67 
68                 this.firstVisibleItem = firstVisibleItem;
69                 this.visibleItemCount = visibleItemCount;
70                 this.totalItemCount = totalItemCount;
71 
72             }
73         });
74 
75     }
76 
77 }

效果圖：