This thread is for discussions of User-Friendly Validation using ErrorProvider.

hi tim first of all this is a nice article, i just have a question
of how do we force the errorprovider to show when the textboxes are in did empty?

tia!

I haven't been able to find any method for programaticly triggering the validation on a TextBox.
Now I set the focus on the TextBox and then to some other control to trigger a validation.

I need a more elegant way to trigger a validation on a TextBox from the code.

(
consider the following example:

I have a form with a combo and 2 textboxes. Changing the selected option in the combo fills the textboxes with the related data from a database. Now the user enters invalid data in one of the textboxes. The errorProvider activates and the icon blinks next to the textbox. The users changes his mind and selects another item in the combo (dropdown list). The textboxes are again filled with relevant data from the database. However the error provider leaves its blinking icon next to the textfield and the user cannot save the data (if he made changes to the other textbox).

I know that I could clear all errors when the selected item in the combo changes, but I'd like to find something more elegant and suitable for other situations as well,  like

txtData.Validate(); or
errProvider.Validate(txtData);
)

Hello,

I've used the Focus() method to get the control to re-validate programmatically...  You'd switch the focus from where it is curently to the control you want to validate and back... Like so...

txtData.Focus();

sender.focus();

 

If anyone has other suggestions, I'd love to hear them.

Hope this helps.

thx...d.

Note that in .NET 2.0 the ErrorProvider control has a known bug where the error message can sporadically disappear and not come back unless the error text changes. One (rather complicated) fix may be found at http://www.codeproject.com/useritems/ErrorProvider_ToolTipFix.asp. Please follow up there if you've found a more straightforward solution to this problem.