how to programmatically hide a button in android sdk

Hello

This tutorial for bignner in android ..
i want to show you how to invisible a button in android using .java file here is your xml file

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#FFFFFF">


<Button android:text="Play"  
    android:id="@+id/play"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:layout_alignParentBottom = "true">
</Button>

<Button android:text="Stop "
    android:id="@+id/stop" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content"
    android:layout_alignParentBottom = "true">
</Button>


</RelativeLayout>  and here is your java file

  playButton = (Button) findViewById(R.id.play);
    playButton.setVisibility(1);
    playButton.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
             //when play is clicked show stop button and hide play button

        }
    });
if you want  want to programmatically show only one button at a time when its click event is called.  here is the solution 


playButton = (Button) findViewById(R.id.play);
    playButton.setVisibility(1);
    playButton.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
             //when play is clicked show stop button and hide play button
             playButton.setVisibility(View.GONE);
             stopButton.setVisibility(View.VISIBLE);

        }
    });


Thanks for today we will meet tomorrow with new topic 
Thank you