今天在做一个简单的数据添加时，使用jQuery的ajax的post操作，发现如果包含尖括号等html格式数据的请求无法发给服务端。
以往的做法就是在页面中或web.config中的pages节点中增加属性validateRequest="false"或者在具体页面中
ValidateRequest="false"增加就可以了。但配置了之后发现还是不行。
在错误描述中可以看出，在.NET 4.0中，需要在webconfig中的httpRuntime配置节中增加属性 requestValidationMode="2.0"。问题解决了。
A potentially dangerous Request.Form value was detected from the client (ProjectName="<script>alert('');</...").
Description:Request Validation has detected a potentially dangerous client input value, and processing of the request has been aborted. This value may indicate an attempt to compromise the security of your application, such as a cross-site scripting attack. To allow pages to override application request validation settings, set the requestValidationMode attribute in the httpRuntime configuration section to requestValidationMode="2.0". Example: <httpRuntime requestValidationMode="2.0" />. After setting this value, you can then disable request validation by setting validateRequest="false" in the Page directive or in the <pages> configuration section. However, it is strongly recommended that your application explicitly check all inputs in this case. For more information, see http://go.microsoft.com/fwlink/?LinkId=153133.
是不是因为corss-site scripting attack日渐猖獗，所以微软才在.NET 4.0中强制进行请求验证呢？还请高人解答。