Validating radiobuttonlist asp net
You will notice that the square will not be calculated and a message will appear to side of the text box indicating that you must enter a value first.Enter a numeric value in the text box and click the square button again, you will note that the error message will disappear and that the square will be calculated and shown in the label.In this tutorial we will provide you with step by step instructions regarding how to utilize these control to benefit from the validation features we mentioned before. only if you know exactly what will be the user input. No one (of course) can know exactly what will be the user input and if that happened then there is no need to make the user provide this input from the first place.This is the case, you cannot validate all types of user inputs..Thanks to , where you can find several controls that can be used to achieve the user input validation scheme we are talking about.Examples of these controls are: Compare Validator, Custom Validator, Range Validator, Regular Expression Validator, Required Field Validator, and Validation Summary.If you asked any experienced developer about what most reduces these scenarios of failure, he will typically answer: "If just I'm sure the value of x is restricted to ..." Being sure from the characteristics of user input does not only reduce these scenarios of failure to a great extent, but also saves you from writing code to handle many cases of input because you are sure that these cases will never arise.It's 'Input Validation' what makes you that sure and lets you focus on the core of your application instead of wasting your time handling every case of input one by one.
This is very important, since this code WILL be reached if the clientside validation is not used, for some reason.
Here's the steps you need to perform: From the toolbox get a Text Box, a Label, a Button, and a Required Field Validator and draw them on your form (Place the Required Field Validator control to the side of the Text Box) In the properties window, set the following properties: Run your application and click the button Congratulations, you are now a user of an application that employ input validation, want to know why?
Simply click the 'Square' button without entering any values.
Please be more specific and ask yourself, what control and what property of that particular control I need to validate?
To help you decide, here's a list of typical controls along with the typically validated property of this control.