要开始使用 F # 使用.NET Core CLIGet started with F# with the .NET Core CLI

本文介绍如何你可以开始使用 F # 在任何操作系统上 （Windows、 macOS 或 Linux） 使用.NET Core CLI。This article covers how you can get started with F# on any operating system (Windows, macOS, or Linux) with the .NET Core CLI. 其中介绍了如何使用控制台应用程序调用的类库构建多项目解决方案。It goes through building a multi-project solution with a class library that is called by a console application.

必备条件Prerequisites

若要开始，必须安装最新.NET Core SDK。To begin, you must install the latest .NET Core SDK.

本文假设你知道如何使用命令行并具有首选文本编辑器。This article assumes that you know how to use a command line and have a preferred text editor. 如果尚未使用该选项， Visual Studio Code是的一个很好的选项F#。If you don't already use it, Visual Studio Code is a great option as a text editor for F#.

构建简单的多项目解决方案Build a simple multi-project solution

打开命令提示符/终端，并使用dotnet new命令创建名为 FSNetCore的新解决方案文件：Open a command prompt/terminal and use the dotnet new command to create new solution file called FSNetCore:

dotnet new sln -o FSNetCore

运行上述命令后，将生成以下目录结构：The following directory structure is produced after running the previous command:

FSNetCore
    ├── FSNetCore.sln

编写类库Write a class library

将目录更改为FSNetCore。Change directories to FSNetCore.

使用 dotnet new 命令，在名为 Library 的src文件夹中创建一个类库项目。Use the dotnet new command, create a class library project in the src folder named Library.

dotnet new classlib -lang "F#" -o src/Library

运行上述命令后，将生成以下目录结构：The following directory structure is produced after running the previous command:

└── FSNetCore
    ├── FSNetCore.sln
    └── src
        └── Library
            ├── Library.fs
            └── Library.fsproj

将 Library.fs 的内容替换为以下代码：Replace the contents of Library.fs with the following code:

module Library

open Newtonsoft.Json

let getJsonNetJson value =
    sprintf "I used to be %s but now I'm %s thanks to JSON.NET!" value (JsonConvert.SerializeObject(value))

将 Newtonsoft.json NuGet 包添加到库项目。Add the Newtonsoft.Json NuGet package to the Library project.

dotnet add src/Library/Library.fsproj package Newtonsoft.Json

使用dotnet .sln add命令将 Library 项目添加到 FSNetCore 解决方案：Add the Library project to the FSNetCore solution using the dotnet sln add command:

dotnet sln add src/Library/Library.fsproj

运行 dotnet build 以生成项目。Run dotnet build to build the project. 生成时将还原未解析的依赖项。Unresolved dependencies will be restored when building.

编写使用类库的控制台应用程序Write a console application that consumes the class library

使用 dotnet new 命令，在名为 "应用" 的src文件夹中创建一个控制台应用程序。Use the dotnet new command, create a console application in the src folder named App.

dotnet new console -lang "F#" -o src/App

运行上述命令后，将生成以下目录结构：The following directory structure is produced after running the previous command:

└── FSNetCore
    ├── FSNetCore.sln
    └── src
        ├── App
        │   ├── App.fsproj
        │   ├── Program.fs
        └── Library
            ├── Library.fs
            └── Library.fsproj

将 Program.fs 文件的内容替换为以下代码：Replace the contents of the Program.fs file with the following code:

open System
open Library

[<EntryPoint>]
let main argv =
    printfn "Nice command-line arguments! Here's what JSON.NET has to say about them:"

    argv
    |> Array.map getJsonNetJson
    |> Array.iter (printfn "%s")

    0 // return an integer exit code

使用dotnet 添加引用添加对 Library 项目的引用。Add a reference to the Library project using dotnet add reference.

dotnet add src/App/App.fsproj reference src/Library/Library.fsproj

使用 dotnet sln add 命令将 App 项目添加到 FSNetCore 解决方案：Add the App project to the FSNetCore solution using the dotnet sln add command:

dotnet sln add src/App/App.fsproj

还原 NuGet 依赖项，dotnet restore 并运行 dotnet build 以生成项目。Restore the NuGet dependencies, dotnet restore and run dotnet build to build the project.

将目录更改为 src/App 控制台项目，并运行将 Hello World 作为参数传递的项目：Change directory to the src/App console project and run the project passing Hello World as arguments:

cd src/App
dotnet run Hello World

应该看到以下结果：You should see the following results:

Nice command-line arguments! Here's what JSON.NET has to say about them:

I used to be Hello but now I'm ""Hello"" thanks to JSON.NET!
I used to be World but now I'm ""World"" thanks to JSON.NET!

后续步骤Next steps

接下来，查看的教程， F# 了解有关不同F#功能的详细信息。Next, check out the Tour of F# to learn more about different F# features.