C errorprovider validating
Here is just the validating event handler’s code: The event driven validation model in Win Forms is powerful and flexible enough to allow you to create high quality apps that implement robust and maintainable validation code in your forms.
Now practice your newly learned skills on your own and experiment with the error provider control!
However, I prefer to call it explicitly and handle all validation at once since you most likely will take action only if the entire control’s children pass validation. The most important thing to recognize here is how precise you can be with the validation error message in the error provider.
There are 2 code paths for validation failure, and in each case we provide the user with an appropriate error message.
You can have as many error providers on a form as you wish, but I can only see a potential use for two.
When the user hovers their mouse over this icon a tooltip is instantly displayed with information about the invalid field. While this may sound trivial, it's actually rather useful. It's up to you how you do your validation, it could be as simple as text length constraints or as advanced as regular expressions matching.Here, you will see a demo of the Errorprovider control with a Tool Tip.When an error message is set, an icon indicating the error will appear next to the control and the error message is displayed as a Tool Tip when the mouse is over the control.I have attached a sample project written in C#, which has a typical (though simplified) data entry form for some customer information.You will find as you tab through the textboxes on the form, that you will get the error icon appearing unless you enter data in the right format.