更新LisView里面的进度条

今天看到论坛上有人问这个。估计是要搞一个类似下载软件的东西吧。

所以就有了本篇，原理：

处理线程先给handler发消息，消息中包括进度信息，handler在去更改List的Adapter里面的信息，并通知List更新UI。

原理很简单，就直接上码了：

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package hol.test.listprogress; 

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import java.util.ArrayList; 

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import java.util.HashMap; 

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import java.util.List; 

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import android.app.Activity; 

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import android.content.Context; 

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import android.os.Bundle; 

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import android.os.Handler; 

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import android.os.Message; 

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import android.view.LayoutInflater; 

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import android.view.View; 

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import android.view.ViewGroup; 

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import android.widget.BaseAdapter; 

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import android.widget.Button; 

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import android.widget.ListView; 

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import android.widget.ProgressBar; 

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import android.widget.TextView; 

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public class TestListProgress extends Activity { 

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    private Button testDo = null; 

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    private ListView progressList = null; 

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    private List<HashMap<String, Object>> list; 

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    private MyAdapter myAdapet; 

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    private MyHandler myHandler; 

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    @Override

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    public void onCreate(Bundle savedInstanceState) { 

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        super.onCreate(savedInstanceState); 

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        setContentView(R.layout.main); 

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        myHandler = new MyHandler(); 

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        findView(); 

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        addListerner(); 

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        initList(); 

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    } 

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    private void findView() { 

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        testDo = (Button) findViewById(R.id.btn_test); 

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        progressList = (ListView) findViewById(R.id.lst_progress); 

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    } 

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    private void addListerner() { 

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        testDo.setOnClickListener(new ClickEvent()); 

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    } 

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    private void initList() { 

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        list = new ArrayList<HashMap<String, Object>>(); 

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        HashMap<String, Object> dataA = new HashMap<String, Object>(); 

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        HashMap<String, Object> dataB = new HashMap<String, Object>(); 

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        dataA.put("title", "dataA"); 

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        dataA.put("current", 0); 

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        list.add(dataA); 

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        dataB.put("title", "dataB"); 

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        dataB.put("current", 0); 

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        list.add(dataB); 

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        myAdapet = new MyAdapter(TestListProgress.this, list); 

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        progressList.setAdapter(myAdapet); 

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    } 

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    // 模拟处理线程 

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    class UpdateRunnable implements Runnable { 

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        int id; 

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        int currentPos = 0; 

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        int delay; 

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        MyHandler handler; 

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        public UpdateRunnable(int id, int delay, MyHandler handler) { 

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            this.id = id; 

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            this.handler = handler; 

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            this.delay = delay; 

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        } 

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        @Override

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        public void run() { 

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            // TODO Auto-generated method stub 

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            while (currentPos <= 100) { 

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                Message msg = handler.obtainMessage(); 

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                msg.what = 1; 

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                msg.arg1 = id; 

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                msg.arg2 = currentPos; 

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                currentPos = currentPos + 5; 

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                msg.sendToTarget(); 

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                try { 

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                    Thread.sleep(delay); 

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                } catch (InterruptedException e) { 

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                    // TODO Auto-generated catch block 

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                    e.printStackTrace(); 

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                } 

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            } 

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        } 

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    } 

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    // 消息Handler用来更新UI 

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    class MyHandler extends Handler { 

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        @Override

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        public void handleMessage(Message msg) { 

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            // TODO Auto-generated method stub 

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            switch (msg.what) { 

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            case 1: 

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                int id = msg.arg1; 

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                int current = msg.arg2; 

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                updateProgress(id, current); 

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                break; 

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            } 

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            super.handleMessage(msg); 

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        } 

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        private void updateProgress(int id, int currentPos) { 

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            HashMap<String, Object> dataTemp = list.get(id); 

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            dataTemp.put("current", currentPos); 

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            myAdapet.chargeProgress(id, dataTemp); 

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        } 

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    } 

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    // 按钮事件 

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    class ClickEvent implements View.OnClickListener { 

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        @Override

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        public void onClick(View v) { 

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            // TODO Auto-generated method stub 

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            switch (v.getId()) { 

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            case (R.id.btn_test): 

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                new Thread(new UpdateRunnable(0, 400, myHandler)).start(); 

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                new Thread(new UpdateRunnable(1, 200, myHandler)).start(); 

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                System.out.println("OnClick"); 

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                break; 

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            } 

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        } 

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    } 

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    // List的显示 

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    class MyAdapter extends BaseAdapter { 

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        List<HashMap<String, Object>> list; 

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        LayoutInflater infl = null; 

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        public MyAdapter(Context context, List<HashMap<String, Object>> list) { 

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            this.infl = (LayoutInflater) context 

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                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE); 

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            this.list = list; 

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        } 

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        @Override

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        public int getCount() { 

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            // TODO Auto-generated method stub 

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            return list.size(); 

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        } 

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        @Override

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        public Object getItem(int position) { 

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            // TODO Auto-generated method stub 

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            return list.get(position); 

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        } 

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        @Override

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        public long getItemId(int position) { 

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            // TODO Auto-generated method stub 

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            return position; 

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        } 

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        @Override

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        public View getView(int position, View convertView, ViewGroup parent) { 

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            // TODO Auto-generated method stub 

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            convertView = infl.inflate(R.layout.list_layout, null); 

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            ProgressBar progressBar = (ProgressBar) convertView 

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                    .findViewById(R.id.progress); 

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            TextView titleView = (TextView) convertView 

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                    .findViewById(R.id.title); 

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            HashMap<String, Object> detail = list.get(position); 

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            String t = (String) detail.get("title"); 

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            titleView.setText(t); 

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            int progress = (Integer) detail.get("current"); 

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            progressBar.setProgress(progress); 

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            return convertView; 

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        } 

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        // 改变进度，postion就是要改的那个进度 

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        public void chargeProgress(int postion, HashMap<String, Object> detail) { 

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            this.list.set(postion, detail); 

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            // System.out.println("charged:" + detail.get("current")); 

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            notifyDataSetChanged(); 

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        } 

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    } 

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}

MyAdapet 里面的 chargeProgress是在用来更新List里面的值。

Message里面arg1就是List中的第几个进度条，arg2就是这个进度条里面的当前应该有的进度。what暂时没什么意义，只是为了标识这类消息是用来更新进度条的。本例也只有这一类消息。

这个是List的LayoutXML文件内容：

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<LinearLayout

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  xmlns:android="http://schemas.android.com/apk/res/android"

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  android:orientation="horizontal"

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  android:layout_width="fill_parent"

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  android:layout_height="fill_parent"> 

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  <TextView  android:id="@+id/title"

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    android:layout_width="wrap_content"

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    android:layout_height="wrap_content"

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    android:text="In list"

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    android:layout_marginRight="5dip"

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    > 

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  </TextView> 

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  <ProgressBar android:id="@+id/progress"

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    android:layout_width="wrap_content"

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    android:layout_height="wrap_content"

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    style="?android:attr/progressBarStyleHorizontal"

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    android:max="100"

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    android:layout_weight="1.0"

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    android:visibility="visible"

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  /> 

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</LinearLayout>

Acitvity的布局：

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

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    android:orientation="vertical"

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    android:layout_width="fill_parent"

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    android:layout_height="fill_parent"

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    > 

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<TextView   

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    android:layout_width="fill_parent" 

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    android:layout_height="wrap_content" 

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    android:text="@string/hello"

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    /> 

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    <Button android:id="@+id/btn_test"

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        android:layout_width="fill_parent"

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        android:layout_height="wrap_content"

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        android:text="ListProgress"

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    /> 

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    <ListView android:id="@+id/lst_progress"

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        android:layout_width="fill_parent"

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        android:layout_height="wrap_content"

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        android:layout_weight="1.0"

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        > 

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    </ListView> 

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</LinearLayout>

效果图如下：

posted on 2011-08-01 16:07 一叶飘舟阅读(574) 评论(0) 收藏举报