.NET Core 2.0迁移小技巧之web.config 配置文件示例详解

前言

相信大家应该都知道.NET Core现在不再支持原来的web.config配置文件了，取而代之的是json或xml配置文件。官方推荐的项目配置方式是使用appsettings.json配置文件，这对现有一些重度使用web.cofig配置的项目迁移可能是不可接受的。

但是好消息是，我们是可以直接在.NET Core 2.0项目种利用上现有的web.config的。本文将详细介绍.NET Core 2.0迁移之web.config 配置文件的相关内容，下面话不多说了，来一起看看详细的介绍吧。

迁移方法

1.首先在解决方案中引入System.Configuration.ConfigurationManager,只有引入它才可以让我们已有的读取web.config代码起作用.

2. 导入web.config文件到项目根目录，并将名称修改为app.config. 因为.NET Core的项目本质是控制台应用，所以ConfigurationManager的API会去默认读取app.config配置文件，而不是web.config配置文件。

3.去除config中和需要的配置无关的内容，主要是<system.web> , <system.webServer>和<system.codedom>等典型asp.net标签。

移除前：

<?xml version="1.0" encoding="utf-8"?>
<configuration> <configSections> <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --> <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" /> </configSections> <connectionStrings> <add name="DefaultConnection" connectionString="Data Source=(LocalDb)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\aspnet-WebApplication24-20170824065102.mdf;Initial Catalog=aspnet-WebApplication24-20170824065102;Integrated Security=True"
 providerName="System.Data.SqlClient" /> </connectionStrings>
 <appSettings>
 <add key="webpages:Version" value="3.0.0.0" />
 <add key="webpages:Enabled" value="false" />
 <add key="ClientValidationEnabled" value="true" />
 <add key="UnobtrusiveJavaScriptEnabled" value="true" />
 <add key="MyKey" value="true"/>
 </appSettings>
 <system.web>
 <compilation debug="true" targetFramework="4.7" />
 <httpRuntime targetFramework="4.7" />
 <httpModules>
 <add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" />
 </httpModules>
 </system.web>
 <runtime>
 <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
 <dependentAssembly>
 <assemblyIdentity name="Newtonsoft.Json" culture="neutral" publicKeyToken="30ad4fe6b2a6aeed" />
 <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="System.Web.Optimization" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="1.1.0.0" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="0.0.0.0-1.5.2.14234" newVersion="1.5.2.14234" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
 <bindingRedirect oldVersion="1.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
 </dependentAssembly>
 </assemblyBinding>
 </runtime>
 <system.webServer>
 <validation validateIntegratedModeConfiguration="false" />
 <modules>
 <remove name="ApplicationInsightsWebTracking" />
 <add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" preCondition="managedHandler" />
 </modules>
 </system.webServer>
 <system.codedom>
 <compilers>
 <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:default /nowarn:1659;1699;1701" />
 <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:default /nowarn:41008 /define:_MYTYPE=\&quot;Web\&quot; /optionInfer+" />
 </compilers>
 </system.codedom>
</configuration>

修改后：

<?xml version="1.0" encoding="utf-8"?>
<configuration>
 <configSections>
 <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
 <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
 </configSections>
 <connectionStrings>
 <add name="DefaultConnection" connectionString="Data Source=(LocalDb)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\aspnet-WebApplication24-20170824065102.mdf;Initial Catalog=aspnet-WebApplication24-20170824065102;Integrated Security=True"
 providerName="System.Data.SqlClient" />
 </connectionStrings>
 <appSettings>
 <add key="webpages:Version" value="3.0.0.0" />
 <add key="webpages:Enabled" value="false" />
 <add key="ClientValidationEnabled" value="true" />
 <add key="UnobtrusiveJavaScriptEnabled" value="true" />
 <add key="MyKey" value="true"/>
 </appSettings>
</configuration>

4.测试原ASP.NET代码，查看读取配置值

using System.Configuration;

namespace WebConfigTest.Configuration
{
 public class ConfigurationService
 {
 public static bool GetConfigValue(string key)
 {
 var result = false;
 var val= ConfigurationManager.AppSettings[key];
 if (val != null)
 {
 result = bool.Parse(val);
 }
 return result;
 }
 }
}

打个断点，看下读取配置值是否正确：

大功告成，读取的配置值完全正确。

大家可以使用这个方法快速迁移现有配置文件和代码过去啦。

总结

以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作能带来一定的帮助，如果有疑问大家可以留言交流，谢谢大家对猪先飞的支持。