在C＃文本框中过滤来自键盘的输入

Question

I want to filter the keyboard inputs into textbox based on the type of input I allow. eg

0 for Digits only 1 for Alphabets only 2 for Alphanumerics

So if 0 is configured and a character 'a' is pressed on the keyboard, it is not shown in the textbox. How do I do that in C#?

Thanks

Answer 1

不确定我是否正确理解了您的问题，但是您可以使用带遮罩的文本框来创建多种类型的输入过滤器。

Answer 2

You need to subscribe to control's KeyPress event (and optionally KeyDown method), and if key stroke must be eaten set Handled property to true. Read more in msdn (with sample that cover your problem).

Answer 3

you can use regular expressions. according to the user input you get, you can change your regular expression/validation method. below is an article that explains how to extend a textbox to validate against regular expressions. hope that helps at least to have some idea. http://www.c-sharpcorner.com/UploadFile/scottlysle/RegExTextBox01022007150131PM/RegExTextBox.aspx