Difference between “@+id/” and “@id/” in Android

Google Android button example source code for developers.

// get handle
Button myButton;
myButton = (Button)findViewById(R.id.idMyButton);
//set focus
myButton.requestFocus();
// set background image
myButton.setBackgroundResource(R.drawable.backImage);
// or
myButton.setBackgroundDrawable(getResources().getDrawable( R.drawable.someImage));

// set visibility
myButton.setVisibility(View.INVISIBLE); // VISIBLE

///////// SET LISTENER
       Button myButton =(Button)findViewById(R.id.button1);
        myButton.setOnClickListener(new Button.OnClickListener() {
            public void onClick(View v) {
                Toast.makeText(getApplicationContext(), "AHOJ",
                    Toast.LENGTH_LONG).show();
            }
        });	

// or set onClickListener
 myButton.setOnClickListener(myListener);
//end onCreate .....
   private OnClickListener myListener = new OnClickListener() {
        public void onClick(View v) {

        }
   }

Photo Gallery of Android SDK Samples.
For better understanding of what the source knows there is a gallery of images.
After clicking on the preview displays the actual size and Titlebar
You can read the path to the source file as: Graphics/AnimateDrawables see the project folder
/ApiDemos/src/com/example/android/apis/graphics/AnimateDrawable.java

This software allow find all IDs from xml layout file source code and create variables with findViewById for onCreate, for onClick and load save preferences functions.
Get all ID is for Windows XP and higher.

2017,04,28
Download 1.0.2.0

[caption id="attachment_903" align="alignleft" width="300" caption="Get all ID from xml file for Android developers utility."][/caption]

Failed to rename directory ....
If using for update Android SDK manager,
try close Eclipse if is open.
Or change security settings of the folder which have problem.
Or disable antivirus for a moment.

public class ApokusActivity extends Activity {
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static class SampleView extends View {

		// CONSTRUCTOR
		public SampleView(Context context) {
			super(context);
			setFocusable(true);

		}
		@Override
		protected void onDraw(Canvas canvas) {
			Paint paint = new Paint();
			
			canvas.drawColor(Color.GREEN);
            
           Bitmap b = Bitmap.createBitmap(200, 200, Bitmap.Config.ALPHA_8);
           Canvas c = new Canvas(b);
           c.drawRect(0, 0, 200, 200, paint);
           
           paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC));
           paint.setTextSize(40);
           paint.setTextScaleX(1.f);
           paint.setAlpha(0);
           paint.setAntiAlias(true);
           c.drawText("Your text", 30, 40, paint);
           paint.setColor(Color.RED);
           
           canvas.drawBitmap(b, 10,10, paint);
		}

	}
}