Gets or sets a value that indicates whether request validation is enabled for this request.
Assembly: System.Web.Mvc (in System.Web.Mvc.dll)
In ASP.NET 4, setting the to false has no effect because validation takes place before the MVC pipeline receives the request. Therefore, in ASP.NET 4 you must set the RequestValidationMode property to a version lower than 4.0. You can configure the validation mode in the Web.config file by using the RequestValidationMode attribute of the httpRuntime element, as shown in the following example:
<system.web> <httpRuntime requestValidationMode="2.0" /> </system.web>
For more information see httpRuntime Element (ASP.NET Settings Schema).