引述 :『As such I’ve been on a mission to discover and document their behavior and present it in a clear and concise manor so here goes.... * All validation controls offer both client and server side validation. * The client side validation is implemented in Javascript. * If Javascript is switched off on the client browser then server side validation provides back up. * If Javascript is enabled and the user input cannot be validated the page never posts back therefore saving bandwidth. * If Javascript is enabled and the user input can be validated then the user input is re-validated on the server side. However if validation fails on the server side code is still executed whereas if validation fails on the client side no server side code runs because the page is never posted back. This means that if there is code that you don’t want to execute if server side validation fails this code MUST be wrapped in a conditional statement that looks something like this: if (this.isValid) The purpose of this behavior is to allow you to have code that executes if validation succeeds, validation fails or in both scenarios.』