Introduction to Android Development (10) Basic Controls 10.3 ProgressBar

ProgressBar provides a visual feedback when performing certain tasks that are being processed. For example, you are downloading data from a Web server, and then you need to update the status of the download. In this case, ProgressBar is a good choice. The following example shows how to use ProgressBar.

1. Create a project, BasicViews2.

2. Code in the Main.xml.

<?xml version= "1.0" encoding= "Utf-8"?> <linearlayout xmlns:android=     
"http://schemas.android.com/apk/" Res/android " 
    android:layout_width=" fill_parent " 
    android:layout_height=" fill_parent " 
    android:o" rientation= "vertical" >     
         
<progressbar android:id= "@+id/progressbar" android:layout_width= "WRAP_" 
    Content "  
    android:layout_height=" wrap_content "/>     
         
</LinearLayout>

3, the code in the Basic2activity.java.

public class Basicviews2activity extends activity {static int progress;     
    ProgressBar ProgressBar;     
    int progressstatus = 0;     
         
    Handler Handler = new Handler (); /** called the activity is a.     
        * * @Override public void onCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);     
                 
        Setcontentview (R.layout.main);     
        progress = 0;     
                 
        ProgressBar = (ProgressBar) Findviewbyid (R.id.progressbar); ---do some work in background thread---new Thread (new Runnable () {public VO     
                ID run () {//?do Some work here?     
         
                while (Progressstatus <) {progressstatus = Dosomework ();     
   }//---Hides the progress bar---             Handler.post (New Runnable () {public void run () {//---0-visible; 4-invisible 8-gone---progres     
                    Sbar.setvisibility (View.gone);     
            }     
                });      
            }//---Do some long running work---private int dosomework () {try {//---simulate doing some work---thre     
                Ad.sleep (500);     
                catch (Interruptedexception e) {e.printstacktrace ();     
            return ++progress;     
    }). Start (); }     
}

4, F11 debugging, you will see ProgressBar animation, 5 Seconds later, the animation disappears.