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 need to set the Data Source, Data Member and Container Control properties of the Error Provider control to set the error for a databound control.
To display the dataset column error, invoke the Set Column Error method of the Error Provider.
We will implement the business rule to allow test appointments to be setup on weekdays only using validation on the form.