args.IsValid

Question

I am working on some new C# asp.net 2010 webforms. I am using the validator controls to make certain the user enters required data accurately. I have heard that we should be using args.IsValid in the controls. However I do not know how to 'write this up'. Can you point me to examples of how I can make my four controls use args.IsValid? I also would like an example of what I check when this value is false.

Javeed M Shaikh · Answer

args is the argument and args.isvalid in the validation control context is for that validation control and page.isvalid is value indicating whether page validation succeeded. usually they both should have the same value.

Javeed M Shaikh · Answer

If you prefer to evaluate everything in Page_Load you can do this by explicitly triggering the validation during this event by calling Page.Validate. After this has been called you can then check the result of Page.IsValid. If you try to query the result of Page.IsValid before Page.Validate has been called either explicitly or being triggered by a button  then its value is meaningless so an exception will be thrown.

dc · Answer

If args.isvalid page.isvalid are really separate items how can their values be the same usually? There must be some kind of an overlap that would set thier values at the same time? Can you tell me when these values can be different?

dc · Answer

Is args.IsValid and page.args.IsValid the same field? If so can you point me to a reference that explains how they are the same? If not I will post my code so you can see what my problem is.

Javeed M Shaikh · Answer

It will be called on button click server side and you can than check for Page.IsValid in the button click event. can you please provide more detail on your issue.

dc · Answer

I have code similar to you. However my problem is what is going to make the 'MyValidationFunc' method execute? If someone does not click on the item in question the 'MyValidationFunc' method will not execute.

Javeed M Shaikh · Answer

Hi DC The args.isvalid is used to get or set the value specified if the validation is passed or failed. here is an example: ControlToValidate=TextBox1 ErrorMessage=My Error Message OnServerValidate=MyValidationFunc runat=server/> and than in code behind: void MyValidationFunc(object source ServerValidateEventArgs args) { try { // do your validation here and if all ok set to true otherwise false. //if all ok args.IsValid = true; //otherwise // args.IsValid = false; } catch(Exception ex) { args.IsValid = false; } }