如何将System.Data.DataSetExtensions的引用添加到Web站点ascx.cs文件？

Question

We're working with a Web Site project and trying to reference System.Data.DataSetExtensions . (Using a Web Application would be better; the technical lead, though, has her reasons.)

Here is what we have tried:

1. Find the assembly path.
2. Open a Visual Studio Command Prompt and run sn.exe -T "full\\path.dll"
3. Add the following to the web.config based on the Public key token.

web.config > system.web >

<compilation debug="true" targetFramework="4.0">
  <assemblies>
    <!-- Other assemblied omitted -->
    <add assembly="System.Data.DataSetExtensions, 
        Version=4.0.0.0, 
        Culture=neutral, 
        PublicKeyToken=B77A5C561934E089" />
  </assemblies>
</compilation>

The full path is C:\\Program Files (x86)\\Reference Assemblies\\Microsoft\\Framework\\.NETFramework\\v4.0\\System.Data.DataSetExtensions.dll

Despite this, msbuild still complains when we add using System.Data.DataSetExtensions to a code behind file. What gives? How do we solve this?

Answer 1

Short Answer

The problem was our using statement. So, there were two requirements.

1. Reference System.Data.DataSetExtensions in the web.config file. (See below for finding the full assembly name.)
2. Add a using statement for System.Data in the C# file.

The problem was that our using statement was for System.Data.DataSetExtensions .

Explanation

Rick Strahl explains that by default ASP.NET includes:

• all assemblies in the bin path
• any GAC-based assembly references in the web.config <compilation> section

Further, we were able to query to GAC from a Visual Studio Command Prompt as follows:

> gacutil /l System.Data.DataSetExtensions

Microsoft (R) .NET Global Assembly Cache Utility.  Version 4.0.30319.17929
Copyright (c) Microsoft Corporation.  All rights reserved.

The Global Assembly Cache contains the following assemblies:
  System.Data.DataSetExtensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, processorArchitecture=MSIL
  System.Data.DataSetExtensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, processorArchitecture=MSIL

Number of items = 2

This confirmed that the assembly we wanted was in the GAC. It also listed the full name of the assembly that we needed to reference in the web.config file.