dependency-injection - F# Unity 设计时配置

Question

可以使其在 C# 中工作:

• 创建名为 UnityCSharp 的 C# 控制台应用
• 添加 Unity NuGet
• 引用System.Configuration
• 添加App.config和C#代码如下，工作正常

C# 的 App.config:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="unity" type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection, Microsoft.Practices.Unity.Configuration"/>
  </configSections>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
  </startup>
  <unity xmlns="http://schemas.microsoft.com/practices/2010/unity">
    <alias alias="myAlias" type="UnityCSharp.ILogger, UnityCSharp" />
    <container>
      <register type="myAlias" mapTo="UnityCSharp.Logger, UnityCSharp" />
      <register type="myAlias" mapTo="UnityCSharp.SpecialLogger, UnityCSharp" name="special" />
    </container>
  </unity>
</configuration>

C#:

using System;
using Microsoft.Practices.Unity;
using Microsoft.Practices.Unity.Configuration;

namespace UnityCSharp
{
    public interface ILogger { string SayHello(); }
    public class Logger : ILogger { public string SayHello() { return "hello"; } }
    public class SpecialLogger : ILogger { public string SayHello() { return "special hello"; } }

    class Program
    {
        static void Main(string[] args)
        {
            var container = new UnityContainer().LoadConfiguration();
            Console.WriteLine(container.Resolve<ILogger>().SayHello()); // --> "hello"
            Console.WriteLine(container.Resolve<ILogger>("special").SayHello()); // --> "special hello"
            Console.ReadLine();
        }
    }
}

但无法在 F# 中重复它(同样是控制台应用程序，名为 UnityFSharp，相同的 NuGet 和 System.Configuration 引用)。

F# 的应用程序配置:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="unity" type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection, Microsoft.Practices.Unity.Configuration"/>
  </configSections>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
  </startup>
  <unity xmlns="http://schemas.microsoft.com/practices/2010/unity">
    <alias alias="myAlias" type="UnityFSharp.ILogger, UnityFSharp" />
    <container>
      <register type="myAlias" mapTo="UnityFSharp.Logger, UnityFSharp" />
      <register type="myAlias" mapTo="UnityFSharp.SpecialLogger, UnityFSharp" name="special" />
    </container>
  </unity>
</configuration>

F#:

open System;
open Microsoft.Practices.Unity
open Microsoft.Practices.Unity.Configuration

type ILogger = abstract SayHello : unit -> string
type Logger() = interface ILogger with member x.SayHello () = "hello"
type SpecialLogger() = interface ILogger with member x.SayHello () = "special hello"

[<EntryPoint>]
let main argv = 
    let container = (new UnityContainer()).LoadConfiguration() // CRASHES HERE
    Console.WriteLine (container.Resolve<ILogger>().SayHello()) // --> "hello"
    Console.WriteLine (container.Resolve<ILogger>("special").SayHello()) // --> "special hello"
    Console.ReadLine() |> ignore
    0

会失败:

The type name or alias myAlias could not be resolved. Please check your configuration file and verify this type name.

我了解 F# 中的命名方式有所不同(http://ilspy.net/ 下面的屏幕截图)。 但我到底怎样才能让它发挥作用呢？ 我尝试过各种 F# 模块、命名空间和 App.config 版本。 只要一个有效的例子就会有所帮助! (我可以重新组织我的 F#)

Answer 1

这里定义类型的方式，它们编译成称为的类型

• 程序+ILogger
• 程序+记录器
• 程序+SpecialLogger

因为它们是在 Program 模块中定义的。

一种选择是编辑配置文件以匹配名称:

<alias alias="myAlias" type="Program+ILogger, UnityFSharp" />
<container>
  <register type="myAlias" mapTo="Program+Logger, UnityFSharp" />
  <register type="myAlias" mapTo="Program+SpecialLogger, UnityFSharp" name="special" />
</container>

我发现的方法是在程序崩溃之前添加一行:

Console.WriteLine typeof<ILogger>

如果您不喜欢这些模块名称，可以将类型放在适当的命名空间中:

namespace Ploeh.Samples

type ILogger = abstract SayHello : unit -> string
type Logger() = interface ILogger with member x.SayHello () = "hello"
type SpecialLogger() = interface ILogger with member x.SayHello () = "special hello"

但是，这需要将它们放入单独的文件中，因为 main 函数是在 Program 模块中定义的。有了上面的命名空间，名称就变成了:

• Ploeh.Samples.ILogger
• Ploeh.Samples.Logger
• Ploeh.Samples.SpecialLogger