ProgressBar

ProgressBar

ProgressBar is a visual indicator of progress in some operation. Displays a bar to the user representing how far the operation has progressed; the application can change the amount of progress (modifying the length of the bar) as it moves forward.



This exercise implemenets a default circle ProgressBar and a Horizontal ProgressBar.

For the Horizontal ProgressBar, a Runnable Thread is implemented to send a message to a Handle to increase the progress of the ProgressBar.

Modify main.xml to add two ProgressBar.

<?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:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:id="@+id/progressbar_default"
 />
<ProgressBar
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    style="?android:attr/progressBarStyleHorizontal"
    android:id="@+id/progressbar_Horizontal"
    android:max="100"
 />
</LinearLayout>

Modify java code.

package com.exercise.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_Horizontal);
        
        new Thread(myThread).start();
    }
    
    private Runnable myThread = 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){
    }
   }
  }
  
  Handler myHandle = new Handler(){

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