WebRequest.Create拋出System.NullReferenceException

Question

我試圖創建WebRequest的實例，但它引發異常。

代碼：

WebRequest request = WebRequest.Create("somURL"); 

錯誤：

System.NullReferenceException: Object reference not set to an instance of an object. 

此代碼工作對當地的環境，但沒有客戶生產服務器上。

注意：客戶端最近更改了託管。 .Net Framework是3.5。

全部例外：

System.Security.SecurityException: Request for the permission of type 'System.Net.WebPermission, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed. at System.Security.CodeAccessSecurityEngine.Check(Object demand, StackCrawlMark& stackMark, Boolean isPermSet) at System.Security.CodeAccessPermission.Demand() at System.Net.HttpWebRequest..ctor(Uri uri, ServicePoint servicePoint) at System.Net.HttpRequestCreator.Create(Uri Uri) at System.Net.WebRequest.Create(Uri requestUri, Boolean useUriBase) at System.Net.WebRequest.Create(String requestUriString) at 

Answer 1

望着例外，它看起來像代碼訪問安全性有提高這一點。我看到類似的線索，請看看。

Security Exception of WebRequest

About Code Access Security