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.NET LED Control in C#

Environment: Written in C# and Windows Forms for .NET. Compiled using VS7 (7.0.9466) and tested using Windows 2000 with the .NET Framework (1.0.3705) I’ve found the Static LED Control contributed by Monte Variakojis for Win32 (MFC and C++) to be very useful and have employed it in many small projects. As a learning exercise, I […]

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Feb 25, 2002

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Environment: Written in C# and Windows Forms for .NET. Compiled using VS7 (7.0.9466) and tested using Windows 2000 with the .NET Framework (1.0.3705)

I’ve found the Static LED Control contributed by Monte Variakojis for Win32 (MFC and C++) to be very useful and have employed it in many small projects. As a learning exercise, I ported his control moving it forward to .NET. This implementation uses C# and Windows Forms. The 16×16 pixel LED bitmap is the original.

If I’ve implemented the control faithfully, the implementations can be
compared and contrasted to evaluate aspects of the new .NET technology. The original is at https://www.codeguru.com/controls/StaticLed.shtml

The LEDs are drawn in a PictureBox image-related Windows Forms control. The PictureBoxLED class inherits from the PictureBox control and overrides its OnPaint message to write the bitmap onto the MessageBox surface. The PictureBoxLED also implements the IBitmapLED interface as does the actual LED (PictureBoxLED16x16). This intermediate stage (PictureBoxLED) could be used to make instances of other sized bitmaps (a Bridge Pattern separating the interface from the implementation). I did substitute a “blink” method, which I find more useful, in place of the “Ping” method in the original.

The bitmap can be loaded from an external file (called “leds.bmp”) or from the internal resource (selected by the LOADFROMRESOURCE define). This is done at the top (FORM) level and the source image is passed all the way down to the drawing component.

Implementation:

Using the LEDs are very simple. In VS.NET, drag a WindowBox from the toolbox onto the design form. Display the properties, change the WindowBox size to 16×16. This is not strictly required as the program will do it but helps with the visual alignment. Use the WindowBox name provided or provide a new one to one of the constructors for PictureBoxLED(). Remember the “*.Parent = this” to hook up the child control for messages. “Using” the PictureBoxLED16x16 and PictureBoxLEDS namespaces.

Operations:

Should operate as the original with a blink method replacing the “Ping” method. See the embedded XML.