Furthermore, it's unnatural to conceptualize the steps of validation as of the data to be validated.
For example, if you were describing the input, you might say, "It should be between five and eight characters; it should be numeric and non-negative; it should always end in the digit '5,' etc." The concept of considering the data qualities rather than the validation process leads to the validation engine discussed in this article.
The Problem You want your program to validate form input, provide feedback to the user, and perhaps take other actions to handle the condition. Limitations This article presents a useful solution, though not a solution for every case.
Each control typically needs a Validating event handler or some other Win Forms way of performing validation. Cancel Button Dialog Result and Finish Button Dialog Result properties to Dialog Result.
Alternatively you could attach to various events of each control and manually set whether the Next button should be enabled or not. Cancel Button Click and Finish Button Click events that fire. None to prevent the Form from auto-closing when those buttons are clicked.
Passing an empty string tells the Error Provider to suppress the error message indicator completely, so it's important not only to set the error message, but also to remove it when no error condition exists.
An Error Provider has these additional advantages over other error-display techniques.
A modular, data-driven validation engine approach provides a more natural interface, more flexibility, and is easier to maintain.
Visual Studio lets you specify property values at design time for a variety of components; using that approach for defining validation attributes is a natural extension, and makes incorporating robust validation simpler for developers.The flexibility of storing validation settings in a configuration file makes validation easy to change, allowing developers and administrators to modifiy or customize validation properties without recompiling and redeployingand without needing the source code.You'll find that using the validation engine discussed here, you can instrument a wide range of validation criteria with very few lines of code.I pretty much get things working in the other 2 solutions, but I cannot get the final result I am looking for and hence am trying my luck with Actipro. I would like Next button (or Back) to be greyed out if any controls are not filled out on that page (could be radio button, textbox, checkbox) 2. Selected Page Is data Collection Page) And (validating Text Box. Length = 0) Then 'User has not entered a description, prompt with error provider error Provider.I would like a double check question on cancel and finish e.g. Set Error(validating Text Box, "Please provide a description.") e.That allows the single Error Provider to simultaneously handle error messages for a multiplicity of controls.