Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEve

查了半天的资料，在一老外的网站上根据老外提示 终于解决了 

原文：

Disable eventvalidation (bad idea, because you lose a little of security that come with very little cost).

Use ASP.NET Ajax UpdatePanel. (Put the listbox in the Updatepanel and trigger a update, if you add or remove listbox. This way viewstate and related fields get updates and eventvalidation will pass.)

Forget client-side and use the classic postback and add or remove the listitems server-side.

大概中文：

eventvalidation=false

用自带的ajax 的UpdatePanel

 判断是否回传

在page_load里 加上if(!isPostBack)