title: How to draw rectangle with transparent inner region?
body: <p>I want to draw rectangle at center of a view like <a href="https://stackoverflow.com/questions/7817236/how-do-you-make-a-resizable-rectangle-for-cropping-images-in-android">this image</a> .For this I am using the following code </p>
  
  <pre><code>public class TransparentView extends View {
  
  
      public TransparentView(Context context, AttributeSet attrs, int defStyle) {
          super(context, attrs, defStyle);
      }
  
      public TransparentView(Context context, AttributeSet attrs) {
          super(context, attrs);
      }
  
      public TransparentView(Context context) {
          super(context);
      }
  
      @Override
      public void draw(Canvas canvas) {
          super.draw(canvas);
          canvas.drawColor(Color.parseColor("#60000000"));
          Paint borderPaint = new Paint();
          borderPaint.setARGB(255, 255, 128, 0);
          borderPaint.setStyle(Paint.Style.STROKE);
          borderPaint.setStrokeWidth(4);
  
          Paint innerPaint = new Paint();
          innerPaint.setARGB(0, 0, 0, 0);
          innerPaint.setAlpha(0);
          innerPaint.setStyle(Paint.Style.FILL);
  
          RectF drawRect = new RectF();
  
          drawRect.set(100, 100, 100,100);
  
          canvas.drawRect(drawRect, innerPaint);
          canvas.drawRect(drawRect, borderPaint);
  
      }
  
  }
  </code></pre>
  
  <p>How can i make complete transparent inside the rectangle and poor transparent at the  outer region?</p>