Drawing Rectangles and Ellipses in a VCL Forms Application
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This procedure draws a rectangle and ellipse in a VCL form.
- Create a VCL form.
- Code the form's OnPaint event handler to draw a rectangle and ellipse.
- Build and run the application.
To create a VCL form and place an image on it
- Choose File > New > Other > Delphi Projects or C++Builder Projects and double-click the VCL Forms Application icon.The VCL Forms Designer is displayed.
- In the form view, click the form, if necessary, to display Form1 in the Object Inspector.
To write the OnPaint event handler
- 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.
- 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
- Choose Run > Run .
- The applications executes, displaying a rectangle in the upper left quadrant, and an ellipse in the same area of the form.