Delphi Tutorials | |
| Working with numbers in Edit Boxes | While the TMaskEdit component will do fine for this job, because of the high number of responses, additional questions and suggestions on this mater in a Delphi forum, I decided to write this small tutorial about creating a new component for solving this goal. |
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Highlight is Rich
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Did you ever notice that the TRichEdit component can change the color of the font for any
series of characters but cannot change the color of the background of a portion of text? If you
have a closer look to its properties you will find both SelAttributes and DefAttributes to be
of type TTextAttributes having only a Color sub-property.
Extend a TRichEdit Delphi component with a Highlight Button that facilitate changing the background of selected text. |
.Net Tutorials and Articles |
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| Num Edit Box |
It seems that is a common sense about when building a Numeric Edit (Text) Box one should validate each character by the time it is typed and reject whatever is not a digit. Well, maybe accept a minus for the first char. Maybe just one dot as the decimal point? What about commas as separators for thousands? In this article I'm going to present another approach: just let the monkey type whatever and do the validation in the end. This way, not only the control would accept decimals, thousands separators or scientific exponent notation, but will also allow and validate pasted values in the box. In the end I'll show you an interesting and unexpected way to extend the usage of this control. And I hope you will get enough knowledge to solve the proposed exercises by yourself. |
| Vertical Labels in Web Pages | A recent project had to display long labels in the header of a table with a lot of columns. While the columns' content kept small, the header was growing huge. The best way to accomplish the task would have been to use 900 rotated texts. However I did not know any techniques for rotating texts in HTML. So - here is the idea of another WebControl for creating a bitmap on the fly and rendering it in the page to simulate a vertical label. |
| Simple WebControl to display Unicode tables |
Ever wondered how the Unicode table looks like?
Then here is a simple control that you may drop on a Web Page to find it out! |
| Numeric Validator for Web Text Controls | Continuing the trend introduced by my previous article Numeric Edit Box, I'm going to use the same technique of validating the text string reducing one char at a time from the end until I'll get a valid number, this time - for Web Pages. And, because Validators exists, this time I'll take a different approach: I'll integrate the code, not in an edit control, but in a validator. |
| Flash LED Control |
This is a small project for Windows applications. It creates a control which simulates a Led light. The Led is round and colorful and it draws itself from the overridden OnPaint method. Additionally to its On/Off functionality, it uses a Timer to rotate a finite number of colors with individually set intervals. Used with imagination it will add fancy effects to your application. |