ASP.NET Core 6引用System.ServiceModel.Security时遇文件未找到错误求助

将类库集成到ASP.NET Core 6客户端应用时，已添加类库引用且编译阶段可正常访问类和方法，但运行时抛出以下错误：

System.IO.FileNotFoundException: 未能加载文件或程序集'System.ServiceModel.Security, Version=4.8.1.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'。系统找不到指定的文件。

已安装.NET Framework 4.8.1运行时，类库引用列表中可见System.ServiceModel.Security，但该引用的运行时版本为v4.0.30319、版本号为4.0.0.0，导致开发无法推进。

相关VB代码如下：

Imports System.ServiceModel
Imports System.ServiceModel.Channels
Imports System.ServiceModel.Security
Imports System.Xml
Imports System.Runtime.Serialization

Public NotInheritable Class GlobalProperties

    Public Shared Function ServiceBinding() As CustomBinding

        Dim binding As New CustomBinding()
        binding.Name = "customBinding"

        Dim security = TransportSecurityBindingElement.CreateUserNameOverTransportBindingElement()
        security.EnableUnsecuredResponse = True
        security.AllowInsecureTransport = True
        security.IncludeTimestamp = False
        security.DefaultAlgorithmSuite = SecurityAlgorithmSuite.Basic256
        security.MessageSecurityVersion = MessageSecurityVersion.WSSecurity10WSTrustFebruary2005WSSecureConversationFebruary2005WSSecurityPolicy11BasicSecurityProfile10

        Dim encoding = New TextMessageEncodingBindingElement()
        encoding.MessageVersion = MessageVersion.Soap11
        encoding.WriteEncoding = System.Text.Encoding.UTF8

        Dim transport = New HttpTransportBindingElement()
        transport.MaxReceivedMessageSize = Integer.MaxValue
        transport.MaxBufferSize = Integer.MaxValue
        transport.HostNameComparisonMode = HostNameComparisonMode.StrongWildcard

        encoding.ReaderQuotas.MaxArrayLength = Convert.ToInt64(16384)
        encoding.ReaderQuotas.MaxDepth = 32
        encoding.ReaderQuotas.MaxStringContentLength = Convert.ToInt64(8192)
        encoding.ReaderQuotas.MaxBytesPerRead = Convert.ToInt64(4096)
        encoding.ReaderQuotas.MaxNameTableCharCount = Convert.ToInt64(16384)

        binding.Elements.Add(security)
        binding.Elements.Add(encoding)
        binding.Elements.Add(transport)

        binding.CloseTimeout = New TimeSpan(0, 1, 0)
        binding.OpenTimeout = New TimeSpan(0, 1, 0)
        binding.ReceiveTimeout = New TimeSpan(0, 10, 0)
        binding.SendTimeout = New TimeSpan(0, 2, 0)

        Return binding

    End Function

End Class

1. 替换为.NET Core兼容的NuGet包 #

ASP.NET Core 6不直接依赖.NET Framework版本的System.ServiceModel.Security，需安装官方提供的跨平台兼容包：

• 在ASP.NET Core 6项目的NuGet包管理器中，安装System.ServiceModel.Security包（选择与.NET 6兼容的6.x系列版本）
• 移除类库中对.NET Framework版本System.ServiceModel.Security的引用，改为引用NuGet包中的版本

2. 添加程序集绑定重定向（针对.NET Framework类库） #

如果类库基于.NET Framework开发，在ASP.NET Core 6项目的runtimeconfig.json或项目配置中添加绑定重定向，将4.8.1.0版本的请求导向已存在的4.0.0.0版本：

{
  "runtimeOptions": {
    "assemblyBinding": {
      "dependentAssembly": [
        {
          "assemblyIdentity": {
            "name": "System.ServiceModel.Security",
            "publicKeyToken": "b03f5f7f11d50a3a",
            "culture": "neutral"
          },
          "bindingRedirect": {
            "oldVersion": "0.0.0.0-4.8.1.0",
            "newVersion": "4.0.0.0"
          }
        }
      ]
    }
  }
}

3. 对齐类库与项目的目标框架 #

• 若类库为.NET Framework项目，建议升级为.NET Standard 2.0或.NET 6，消除跨框架引用的兼容性冲突
• 若无法升级类库，确保其目标框架版本不高于.NET Framework 4.8，并在ASP.NET Core项目的.csproj文件中确认兼容配置正确：

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
  </PropertyGroup>
</Project>

4. 清理重建项目 #

• 删除项目的bin和obj目录
• 清理NuGet缓存后重新还原所有包
• 重新编译并运行项目

内容的提问来源于stack exchange，提问作者Mohamed Nuhid