Drawing Rectangles and Ellipses in a Windows VCL Application

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This procedure draws a rectangle and ellipse in a VCL form.

  1. Create a VCL form.
  2. Code the form's OnPaint event handler to draw a rectangle and ellipse.
  3. Build and run the application.

To create a VCL form and place an image on it

  1. Open File > New > Windows VCL Application - Delphi
  2. In the form view, click the form, if necessary, to display Form1 in the Object Inspector.

To write the OnPaint event handler

  1. In the Object Inspector, double-click the Form1 OnPaint event on the Events tab.The Code Editor displays with the cursor in the TForm1.FormPaint (Delphi) or TForm1::FormPaint (C++) event handler block.
  2. Enter the following event handling code:
Canvas.Rectangle (0, 0, ClientWidth div 2, ClientHeight div 2);
Canvas.Ellipse (0, 0, ClientWidth div 2, ClientHeight div 2);
Canvas->Rectangle( 0, 0, ClientWidth / 2, ClientHeight / 2 );
Canvas->Ellipse( 0, 0, ClientWidth / 2, ClientHeight / 2 );

To run the program

  1. Choose Run > Run .
  2. The applications executes, displaying a rectangle in the upper left quadrant, and an ellipse in the same area of the form.

See Also