Numeric UpDown Control for hardware control applications or yet another SpinEdit

• Download IgSpinEdit_demo - 42.82 KB
• Download IgSpinEdit_src - 15.59 KB

Introduction

For many of my projects, which are mainly related to controlling hardware, I need a numeric UpDown (SpinEdit) control which could easily and quickly change value extending along many orders of magnitude, let say to change frequency from 1 to 2 GHz and then add 200 Hz more. Unfortunately standard controls provided by Borland VCL or .Net do not satisfy this requirement. Search among third party controls was not successful too as I needed some specific capabilities, most notably the value late update. Under the late update I mean that for hardware control application it is common that SpinEdit controls value on remote device and thus it is desirable to initiate value change by SpinEdit, but postpone actual Value change until hardware confirms that parameter has been changed.

The simple IgSpinEdit control offered in this article provides required functionality. It was originally developed for Borland C Builder, but as I started to use .Net some time ago I ported it to C# and improved a bit. I am not going to discuss actual code in this article, it is present in zip file, but only give brief explanation of major properties.

Using the Code

The control is built upon UserControl and provides the following original features:

Other properties and events are inherited from UserControl.

The control does not try to prevent all possible erroneous parameter combinations, so please apply common sense while setting control properties and it will work quite well.

The Control is accompanied with simple test application showing how to use the control and allowing playing with parameters. The application screenshot is presented at the beggining of the article.

One important thing to note is that IgSpinEdit implements ISupportInitialize interface to handle correct initialization. Fortunately VS Designer automatically handles calls to ISupportInitialize BeginInit()/EndInit() pair, so you should not do it yourself.

For test convenience an "External update" handler is implemented in lower left corner of the test application and it handles ValueChanging event of all IgSpinEdit controls. Please note that on application start up only “Value as Int” has ExternalUpdate set what prevents it from changing value until Update button is pressed.

Conclusion

This article presents extended numeric UpDown control which is especially useful for hardware control applications. There is nothing fancy in it, but I found it really useful for my projects. I hope some readers will agree with me.
Feel free to use provided code in any way you wish. Comments and suggestions are welcome.

History

06-18-2008:

• Original article