更新LisView裡面的進度條

  今天看到論壇上有人問這個。估計是要搞一個類似下載軟件的東西吧。

  所以就有了本篇，原理：

  處理線程先給handler發消息，消息中包括進度信息，handler在去更改List的Adapter裡面的信息，並通知List更新UI。

  原理很簡單，就直接上碼了：

  001 package hol.test.listprogress; 002    003 import java.util.ArrayList; 004 import java.util.HashMap; 005 import java.util.List; 006    007 import android.app.Activity; 008 import android.content.Context; 009 import android.os.Bundle; 010 import android.os.Handler; 011 import android.os.Message; 012 import android.view.LayoutInflater; 013 import android.view.View; 014 import android.view.ViewGroup; 015 import android.widget.BaseAdapter; 016 import android.widget.Button; 017 import android.widget.ListView; 018 import android.widget.ProgressBar; 019 import android.widget.TextView; 020    021 public class TestListProgress extends Activity { 022     private Button testDo = null; 023     private ListView progressList = null; 024     private List<HashMap<String, Object>> list; 025     private MyAdapter myAdapet; 026     private MyHandler myHandler; 027    028     @Override 029     public void onCreate(Bundle savedInstanceState) { 030         super.onCreate(savedInstanceState); 031         setContentView(R.layout.main); 032    033         myHandler = new MyHandler(); 034    035         findView(); 036         addListerner(); 037         initList(); 038     } 039    040     private void findView() { 041         testDo = (Button) findViewById(R.id.btn_test); 042         progressList = (ListView) findViewById(R.id.lst_progress); 043     } 044    045     private void addListerner() { 046         testDo.setOnClickListener(new ClickEvent()); 047     } 048    049     private void initList() { 050         list = new ArrayList<HashMap<String, Object>>(); 051         HashMap<String, Object> dataA = new HashMap<String, Object>(); 052         HashMap<String, Object> dataB = new HashMap<String, Object>(); 053         dataA.put("title", "dataA"); 054         dataA.put("current", 0); 055         list.add(dataA); 056         dataB.put("title", "dataB"); 057         dataB.put("current", 0); 058         list.add(dataB); 059    060         myAdapet = new MyAdapter(TestListProgress.this, list); 061         progressList.setAdapter(myAdapet); 062    063     } 064    065     // 模擬處理線程 066     class UpdateRunnable implements Runnable { 067         int id; 068         int currentPos = 0; 069         int delay; 070         MyHandler handler; 071    072         public UpdateRunnable(int id, int delay, MyHandler handler) { 073             this.id = id; 074             this.handler = handler; 075             this.delay = delay; 076         } 077    078         @Override 079         public void run() { 080             // TODO Auto-generated method stub 081             while (currentPos <= 100) { 082                 Message msg = handler.obtainMessage(); 083                 msg.what = 1; 084                 msg.arg1 = id; 085                 msg.arg2 = currentPos; 086                 currentPos = currentPos + 5; 087                 msg.sendToTarget(); 088                 try { 089                     Thread.sleep(delay); 090                 } catch (InterruptedException e) { 091                     // TODO Auto-generated catch block 092                     e.printStackTrace(); 093                 } 094             } 095         } 096    097     } 098    099     // 消息Handler用來更新UI 100     class MyHandler extends Handler { 101         @Override 102         public void handleMessage(Message msg) { 103             // TODO Auto-generated method stub 104             switch (msg.what) { 105             case 1: 106                 int id = msg.arg1; 107                 int current = msg.arg2; 108                 updateProgress(id, current); 109                 break; 110             } 111             super.handleMessage(msg); 112         } 113    114         private void updateProgress(int id, int currentPos) { 115             HashMap<String, Object> dataTemp = list.get(id); 116             dataTemp.put("current", currentPos); 117             myAdapet.chargeProgress(id, dataTemp); 118         } 119     } 120    121     // 按鈕事件 122     class ClickEvent implements View.OnClickListener { 123    124         @Override 125         public void onClick(View v) { 126             // TODO Auto-generated method stub 127             switch (v.getId()) { 128             case (R.id.btn_test): 129                 new Thread(new UpdateRunnable(0, 400, myHandler)).start(); 130                 new Thread(new UpdateRunnable(1, 200, myHandler)).start(); 131                 System.out.println("OnClick"); 132                 break; 133             } 134         } 135    136     } 137    138     // List的顯示 139     class MyAdapter extends BaseAdapter { 140    141         List<HashMap<String, Object>> list; 142         LayoutInflater infl = null; 143    144         public MyAdapter(Context context, List<HashMap<String, Object>> list) { 145             this.infl = (LayoutInflater) context 146                     .getSystemService(Context.LAYOUT_INFLATER_SERVICE); 147             this.list = list; 148         } 149    150         @Override 151         public int getCount() { 152             // TODO Auto-generated method stub 153             return list.size(); 154         } 155    156         @Override 157         public Object getItem(int position) { 158             // TODO Auto-generated method stub 159             return list.get(position); 160         } 161    162         @Override 163         public long getItemId(int position) { 164             // TODO Auto-generated method stub 165             return position; 166         } 167    168         @Override 169         public View getView(int position, View convertView, ViewGroup parent) { 170             // TODO Auto-generated method stub 171             convertView = infl.inflate(R.layout.list_layout, null); 172             ProgressBar progressBar = (ProgressBar) convertView 173                     .findViewById(R.id.progress); 174             TextView titleView = (TextView) convertView 175                     .findViewById(R.id.title); 176    177             HashMap<String, Object> detail = list.get(position); 178             String t = (String) detail.get("title"); 179             titleView.setText(t); 180             int progress = (Integer) detail.get("current"); 181             progressBar.setProgress(progress); 182             return convertView; 183         } 184    185         // 改變進度，postion就是要改的那個進度 186         public void chargeProgress(int postion, HashMap<String, Object> detail) { 187             this.list.set(postion, detail); 188             // System.out.println("charged:" + detail.get("current")); 189             notifyDataSetChanged(); 190         } 191    192     } 193 }   MyAdapet 裡面的 chargeProgress是在用來更新List裡面的值。   Message裡面arg1就是List中的第幾個進度條，arg2就是這個進度條裡面的當前應該有的進度。what暫時沒什麼意義，只是為了標識這類消息是用來更新進度條的。本例也只有這一類消息。   這個是List的LayoutXML文件內容：

 

  01 <LinearLayout 02   xmlns:android="http://schemas.android.com/apk/res/android" 03   android:orientation="horizontal" 04   android:layout_width="fill_parent" 05   android:layout_height="fill_parent"> 06   <TextView  android:id="@+id/title" 07     android:layout_width="wrap_content" 08     android:layout_height="wrap_content" 09     android:text="In list" 10     android:layout_marginRight="5dip" 11     > 12   </TextView> 13   <ProgressBar android:id="@+id/progress" 14     android:layout_width="wrap_content" 15     android:layout_height="wrap_content" 16     style="?android:attr/progressBarStyleHorizontal" 17     android:max="100" 18     android:layout_weight="1.0" 19     android:visibility="visible" 20   /> 21 </LinearLayout>   Acitvity的布局：

 

  01 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 02     android:orientation="vertical" 03     android:layout_width="fill_parent" 04     android:layout_height="fill_parent" 05     > 06 <TextView   07     android:layout_width="fill_parent"  08     android:layout_height="wrap_content"  09     android:text="@string/hello" 10     /> 11     <Button android:id="@+id/btn_test" 12         android:layout_width="fill_parent" 13         android:layout_height="wrap_content" 14         android:text="ListProgress" 15     /> 16     <ListView android:id="@+id/lst_progress" 17         android:layout_width="fill_parent" 18         android:layout_height="wrap_content" 19         android:layout_weight="1.0" 20         > 21     </ListView> 22 </LinearLayout>   效果圖如下：