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 }
时间： 2024-10-29 08:26:49