Invalid postback or callback argument

每次 request 還沒來得急接收到 response 就又再點其它按鈕），會發生 Invalid postback or callback argument 錯誤:

Invalid postback or callback argument. Event validation is enabled using
in configuration or <%@ Page
EnableEventValidation="true" %> in a page. For security purposes, this
feature verifies that arguments to postback or callback events originate
from the server control that originally rendered them. If the data is valid
and expected, use the ClientScriptManager.RegisterForEventValidation method
in order to register the postback or callback data for validation.
Description: An unhandled exception occurred during the execution of the
current web request. Please review the stack trace for more information
about the error and where it originated in the code.

Solution:

if you created a sub procedure that populates your
datalist and you are calling it when the user clicks a button within
your itemtemplate, after the data processing has been done (or whatever
processing you're doing with that button), make sure that it isn't also
being called in your Page_load sub. When your page FIRST loads and you
populate the datalist control, make sure that you have it within a If
Not Page.IsPostBack and not where it gets called on every load.