为什么我的程序不会在 GAC 中查找程序集？答案

【问题标题】：Why won't my program look in the GAC for an assembly?为什么我的程序不会在 GAC 中查找程序集？
【发布时间】：2012-01-12 07:06:55
【问题描述】：

我有一项服务可以将一堆程序集作为插件加载。这些插件中的每一个都引用安装在 GAC 中的通用程序集。出于某种原因，一些插件能够成功地从 GAC 加载程序集，但其他插件失败。我似乎无法弄清楚为什么会发生这种情况。以下是一个有效而无效的 Fusion 日志：

*** Assembly Binder Log Entry  (12/3/2011 @ 10:54:47 AM) ***



The operation was successful.
Bind result: hr = 0x0. The operation completed successfully.

Assembly manager loaded from:  C:\Windows\Microsoft.NET\Framework\v4.0.30319\clr.dll
Running under executable  C:\Windows\Microsoft.NET\Framework\v4.0.30319\AddInProcess.exe
--- A detailed error log follows. 

=== Pre-bind state information ===
LOG: User = NT AUTHORITY\SYSTEM
LOG: DisplayName = OSAE.API, Version=1.0.0.0, Culture=neutral, PublicKeyToken=f47a6446f36f79f7
 (Fully-specified)
LOG: Appbase = file:///C:/Program Files/OSA/AddIns/ZWave
LOG: Initial PrivatePath = NULL
LOG: Dynamic Base = NULL
LOG: Cache Base = NULL
LOG: AppName = NULL
Calling assembly : OSAE.Zwave, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null.
===
LOG: This bind starts in default load context.
LOG: No application configuration file found.
LOG: Using host configuration file: 
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config.
LOG: Post-policy reference: OSAE.API, Version=1.0.0.0, Culture=neutral, PublicKeyToken=f47a6446f36f79f7
LOG: Found assembly by looking in the GAC.
LOG: Binding succeeds. Returns assembly from C:\Windows\Microsoft.Net\assembly\GAC_MSIL\OSAE.API\v4.0_1.0.0.0__f47a6446f36f79f7\OSAE.API.dll.
LOG: Assembly is loaded in default load context.

失败：

*** Assembly Binder Log Entry  (12/3/2011 @ 10:54:46 AM) ***

The operation failed.
Bind result: hr = 0x80070002. The system cannot find the file specified.

Assembly manager loaded from:  C:\Windows\Microsoft.NET\Framework\v4.0.30319\clr.dll
Running under executable  C:\Windows\Microsoft.NET\Framework\v4.0.30319\AddInProcess.exe
--- A detailed error log follows. 

=== Pre-bind state information ===
LOG: User = NT AUTHORITY\SYSTEM
LOG: DisplayName = OSAE.API, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
 (Fully-specified)
LOG: Appbase = file:///C:/Program Files/OSA/AddIns/Web Server
LOG: Initial PrivatePath = NULL
LOG: Dynamic Base = NULL
LOG: Cache Base = NULL
LOG: AppName = NULL
Calling assembly : OSAE.WebServer, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null.
===
LOG: This bind starts in default load context.
LOG: No application configuration file found.
LOG: Using host configuration file: 
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config.
LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind).
LOG: Attempting download of new URL file:///C:/Program Files/OSA/AddIns/Web Server/OSAE.API.DLL.
LOG: Attempting download of new URL file:///C:/Program Files/OSA/AddIns/Web Server/OSAE.API/OSAE.API.DLL.
LOG: Attempting download of new URL file:///C:/Program Files/OSA/AddIns/Web Server/OSAE.API.EXE.
LOG: Attempting download of new URL file:///C:/Program Files/OSA/AddIns/Web Server/OSAE.API/OSAE.API.EXE.
LOG: All probing URLs attempted and failed.

【问题讨论】：

我假设程序集是强签名的 - 它是如何作为对无法加载它的项目的引用添加的？
在两种情况下都以相同的方式添加了引用。添加参考 -> 浏览 -> 选择 dll
那么，您是从文件位置手动选择 DLL 的吗？还是项目参考？还是来自 GAC？哪一个？
我从文件位置手动选择 DLL
引用是否添加了PublicKeyToken？

标签： c# .net assemblies gac fusion

【解决方案1】：

失败的程序集没有强签名（PublicKey=null）。我不知道为什么程序集没有签名，但是加载程序不需要在 GAC 中查找此类程序集，因为只有强签名的程序集才能进入 GAC。

【讨论】：