He is a published author on several subjects including XML, the migration from Visual Basic 6 to VB. In this scenario, if an error occurs while performing validation on the user's computer, the application can directly display the error message on the page that the user is viewing without the page making a round trip to the Web server and then back to the user. NET, data validation was performed through scripts using either Java Script or VBScript.The malicious user can then submit the modified script to the Web server with results that are different than what you, the developer, intended.
All of the data validation controls are displayed in the toolbox when ASP.
NET displays a Web form or Web user control in design view in Visual Studio . You can also (directly in HTML or programmatically) add data validation controls to Web forms and Web user controls. NET data validation control is the Required Field Validator control.
In the snippet that follows I've indicated the HTML to generate both an asp: Text Box control and a linked asp: Required Field Validator control.
In the snippet above I've declared a textbox with an ID attribute called txt Name.
This increases performance and reduces traffic over the Web.
A slightly negative aspect of validating data on the user's computer is that the validation is performed via a script residing in the Web page. You only have two possible scripting languages that you can use on a user's computer: VBScript or Java Script.Furthermore, the data validation scripts are protected inside the Web server so they are not vulnerable to malicious user modifications.In its efforts to improve Web development on the whole, Microsoft included in ASP. NET validation controls), which offer an exceptional solution to data validation. NET comes with five validation controls as well as a summary control. NET Web application renders the data validation controls on the user's computer as HTML elements based upon the selected Target Schema property.If you choose to support validation on the user's computer, performance will increase slightly.However, to reiterate, validation will always be performed on the Web server in order to offer validation to Web browsers that do not support the client-side scripting as well as protect against the possibility of modified validation scripts.This decreases performance since the page must make a round trip to the Web server and back to the user's computer if data validation fails.