为什么在运行时找不到我的项目的 DLL referenced/used?

Why is a DLL referenced/used by my project not found at runtime?

我已将几个 iTextSharp DLL 添加到 Sharepoint 2010 项目(作为 WebPart 部署)。

Web 部件 compiles/runs 很好(我可以在与 Sharepoint 站点页面上的 Web 部件交互的同时单步执行我的 WebPart 项目)。也就是说,它运行良好,直到调用实际使用 itextsharp.dll 的代码。然后,页面崩溃,我得到(在日志文件中),"The system cannot find the file specified"

是否必须将 DLL 部署到特定位置以便 Sharepoint 找到它们,或者...???

更新

即使将四个 itextsharp DLL 复制到 C:\Windows\Microsoft.NET(Windows Server 2008、.NET 3.5),我仍然收到相同的错误消息。

有关日志文件中的详细信息:

03/30/2015 14:49:28.43  w3wp.exe (0x0968)                           0x1834  SharePoint Foundation           Runtime                         tkau    Unexpected  System.IO.FileNotFoundException: Could not load file or assembly 'itextsharp, Version=5.5.5.0, Culture=neutral, PublicKeyToken=6574839201' or one of its dependencies. The system cannot find the file specified.    at XMLToPDF.XMLToPDFWebPart.XMLToPDFWebPart.ConvertFromXMLToPDF(List`1 listOfListItems)     at XMLToPDF.XMLToPDFWebPart.XMLToPDFWebPart.btnSave_Click(Object sender, EventArgs e)     at System.Web.UI.WebControls.Button.OnClick(EventArgs e)     at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)     at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)     at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)  ef8cece3-42f4-47d0-ab0a-ca2f0fff46e4

link provided by user2864740 是关键。

简而言之,这就是我所做的:

   2-clicked Package.package
   Selected the "Advanced" button
   Selected the "Add" > "Add Existing Assembly" button
   Verified "GlobalAssemblyCache" was selected
   Using the ellipsis button affiliated with the "Source Path" edit, added each needed DLL one at a time
   Saved Package.package

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