動態的進度條(ProgressBar)

在進度條(ProgressBar)一篇文章中, 顯示了靜態的進度條. 現在來實現一個動態的進度條.



我們實施了一個可運行的線程(Runable Thread), 來產生信息(Message); (我們不能在此線程直接更新進度條, 因為祗有創建該UI的線程能夠變更該UI)

另一方面我們實施了一個Handle來處理信息, 以更新進度條.

修改main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
<ProgressBar
    android:id="@+id/progressbar" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content"
    style="?android:attr/progressBarStyleHorizontal"
    android:max="100"
    />
</LinearLayout>

主程序

package com.AndroidProgressBar;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.ProgressBar;

public class AndroidProgressBar extends Activity {
 
 ProgressBar myProgressBar;
 int myProgress = 0;
 
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);       
       
        myProgressBar = (ProgressBar)findViewById(R.id.progressbar);
        myProgressBar.setProgress(myProgress);
        
        new Thread(new Runnable(){

   @Override
   public void run() {
    // TODO Auto-generated method stub
    while(myProgress<100){
     try{
      myHandle.sendMessage(myHandle.obtainMessage());
      Thread.sleep(1000);
     }catch(Throwable t){
     }
    }
   }
        }).start();
        
    }
    
    Handler myHandle = new Handler(){

  @Override
  public void handleMessage(Message msg) {
   // TODO Auto-generated method stub
   myProgress++;
   myProgressBar.setProgress(myProgress);
  }
    };
}