Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
Generating Simple Graphics
Collapse the table of content
Expand the table of content

Generating Simple Graphics

Visual Studio 6.0

Generating simple graphics is a relatively easy task. Visual Basic includes the Circle, Line, and PSet methods for drawing circles, lines, and points, respectively.

The code in Listing 9.10 shows how to create a circle with a radius of 0.5 inch (720 twips) centered at a location 1 inch down and 1 inch over (1440 by 1440 twips). Then a square is drawn, with each side 1 inch long (hint: 2160 twips equal 1.5 inches). Finally, I make a point in the exact center of the circle and the square. Figure 9.9 shows the results.

Listing 9.10: Command7_Click Event in Print

Private Sub Command7_Click()
Picture1.Circle (1440, 1440), 720
Picture1.Line (720, 720)-(2160, 720)
Picture1.Line (2160, 720)-(2160, 2160)
Picture1.Line (2160, 2160)-(720, 2160)
Picture1.Line (720, 2160)-(720, 720)
Picture1.PSet (1440, 1440)

End Sub

Figure 9.9: You can use Visual Basic’s drawing methods to create a square, a circle, and a point.

Inches, Centimeters, Pixels, or Twips

You can use any of the four measuring systems when you specify coordinates for these graphic methods, as follows:

  • Set the ScaleMode property to 5 to specify coordinates in inches.

  • Set the ScaleMode property to 7 to specify coordinates in centimeters.

  • Set the ScaleMode property to 3 to specify coordinates in pixels.

  • Set the ScaleMode property to 1 to specify coordinates in twips.

At one time or another, I’ve tried each of these scales and had problems. I forgot to set ScaleMode when I created a new control, or somehow ScaleMode would get reset back to twips. Or worse, the scales were user-defined—so who knew what values were legal coordinates? Finally, I gave up and decided to memorize 1,440 twips = 1 inch. Now I write code like 1440*2 instead of 2.0 inches. Performance-wise, there shouldn’t be a difference, since the compiler should optimize that 1440*2 to 2880.

© 1998 SYBEX Inc. All rights reserved.

Show:
© 2015 Microsoft