How to show/Hide Navigation Drawer programmatically

How can I use button to show/hide Navigation Drawer, I have used this SO link to create and manage Navigation Drawer.

Now i am using (Swipe to right from left - to show) and (Swipe from right to left - to hide)

How may I show/Hide Drawer using button highlighted in below screenshot:

header_home.xml:

<RelativeLayout        
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="wrap_content"
    android:layout_width="fill_parent"
    android:id="@+id/header_layout" 
    android:gravity="fill_horizontal" 
    android:layout_gravity="top|center">
    

 <TextView
    android:id="@+id/textHeader"
    android:text="Home"
    android:textColor="#ffffff"
    android:gravity="center"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/bg_header"
 />

 <ImageButton
    android:id="@+id/btnDrawer"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="10dp"
    android:layout_alignParentLeft="true"
    android:layout_centerVertical="true"
    android:adjustViewBounds="true"
    android:background="@drawable/icon_drawer"
    android:contentDescription="@string/app_name"
    />
 

Edited:

     btnMenu.setOnClickListener(new OnClickListener() {
		
		@Override
		public void onClick(View v) {
			// TODO Auto-generated method stub
			drawer.openDrawer(Gravity.LEFT);				
		}
	});

I know to close i have to call drawer.closeDrawer(Gravity.LEFT); but where i have to place this code ?

Grab a reference to the DrawerLayout and call closeDrawer(int) to close it and openDrawer(int) to open it. The int parameter refers to the gravity. In your case it should be GravityCompat.LEFT/ GravityCompat.START, because accordingly to the screenshot you posted, your DrawerLayout open and close on the left.

to Close Drawer:

drawer.CloseDrawer((int)GravityFlags.Left);

to Open Drawer:

drawer.OpenDrawer((int)GravityFlags.Left);

To open the Drawer

DrawerLayout drawer = findViewById(R.id.drawer_layout);
drawer.openDrawer(GravityCompat.START);

To close the drawer

DrawerLayout drawer = findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);

I might be late for this but here is the solution you are looking for:

btnMenu.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
         if(drawer.isDrawerOpen(GravityCompat.START)){
                drawerLayout.closeDrawer(GravityCompat.START);
            }
            else {
                drawerLayout.openDrawer(GravityCompat.START);
            }                
    }
});

If you are using Sliding Drawer Menu, and you want to hide the menu when it is open (when drag from right to left). Then we have to deal with listview object ontouch listener. The code will be like this.

	//((( When we drage from Right to left then menu hide ))))
	lvMenu.setOnTouchListener(new OnTouchListener() {
	    @Override
	    public boolean onTouch(View v, MotionEvent event) {

	        switch (event.getAction()) 
	        {
	            case MotionEvent.ACTION_DOWN:
	            	toggleMenu(v);		            
	                break;

	            case MotionEvent.ACTION_UP:
	                //showtoast("up");
	                break;

	            default:
	                return false;
	        }
	        return false;
	    }

		
	});
 
     public void toggleMenu(View v) {
	mLayout.toggleMenu();
}

For complete code, you can put the comment here, if you have any problem