在 .NET Core 2.0 中设置环境变量

Question

我正在尝试在我的 .NET Core 2.0 应用程序中设置多个环境。请参阅下面的代码。

配置文件（Launch.JSON）

"configurations": [
    {
        "name": ".NET Core Launch (web)",
        "type": "coreclr",
        "request": "launch",
        "preLaunchTask": "build",
        // If you have changed target frameworks, make sure to update the program path.
        "program": "${workspaceRoot}/my.api/bin/Debug/netcoreapp2.0/my.api.dll",
        "args": [],
        "cwd": "${workspaceRoot}/my.api",
        "stopAtEntry": false,
        "requireExactSource": false,
        "internalConsoleOptions": "openOnSessionStart",
        "launchBrowser": {
            "enabled": true,
            "args": "${auto-detect-url}",
            "windows": {
                "command": "cmd.exe",
                "args": "/C start ${auto-detect-url}"
            },
            "osx": {
                "command": "open"
            },
            "linux": {
                "command": "xdg-open"
            }
        },
        "env": {
            "ASPNETCORE_ENVIRONMENT": "Development"
        },
        "sourceFileMap": {
            "/Views": "${workspaceRoot}/Views"
        }
    },
    {
        "name": ".NET Core Attach",
        "type": "coreclr",
        "request": "attach",
        "processId": "${command:pickProcess}"
    }
]

程序.cs

public class Program
{
    public static void Main(string[] args)
    {
        BuildWebHost(args).Run();
    }

    public static IWebHost BuildWebHost(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .UseStartup<Startup>()
            .Build();
}

StartUp.cs

public class Startup
{
    public IContainer ApplicationContainer { get; private set; }
    private IHostingEnvironment HostingEnvironment { get; set; }
    public IConfigurationRoot Configuration { get; }
    private string ConnectionString
    {
        get
        {
            return this.HostingEnvironment.IsDevelopment() ? Configuration.GetConnectionString("DefaultConnection") : Configuration.GetConnectionString("Production");
        }
    }

    public Startup(IHostingEnvironment env)
    {
        var builder = new ConfigurationBuilder()
            .SetBasePath(env.ContentRootPath)
            .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
            .AddJsonFile($"appsettings.Development.json", optional: true, reloadOnChange: true)
            .AddJsonFile($"appsettings.Azuredev.json", optional: true, reloadOnChange: true)
            .AddEnvironmentVariables();

        Configuration = builder.Build();

        this.HostingEnvironment = env;

        System.Console.WriteLine(env.EnvironmentName); // Here it always give me Production.
    }

我的问题

我尝试使用 dotnet run --environment "Development"

之类的命令行

所以，它应该在 Development Environment 上运行，但它总是在 Production 下运行，（看我在我的startup.cs 文件）

现在奇怪的是，如果我使用 F5 进行调试，那么它可以在 development 环境中完美运行。

Answer 1

dotnet run --environment 对ASPNETCORE_ENVIRONMENT 环境变量没有影响，请参阅this issue。

这里有一个关于如何以多种方式切换环境的详细说明：https://docs.microsoft.com/en-us/aspnet/core/fundamentals/environments

例如，您可以从命令行运行它（dotnet run 之前）：set ASPNETCORE_ENVIRONMENT=Development

Answer 2

您可以更新您的 launchsettings.json 以包含“开发”配置文件，然后运行：

dotnet run --launch-profile "Development"

有关 launchSettings.json 文件配置的更多详细信息，请参阅Working with multiple environments

请注意，commandName 可能需要为“Project”（我还没有真正尝试过这么多）。示例launchSettings.json如下：

{
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "http://localhost:19882/",
      "sslPort": 0
    }
  },
  "profiles": {
    "Development": {
      "commandName": "Project",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

Answer 3

我终于做到了……

让我们看看我是如何做到这一点的。

1. 我已在 launchSettings.JSON 中添加了我的所有配置文件设置
2. Program.cs 与我在问题中添加的相同。
3. 更新了 startup.cs（见下文）
4. 通过终端运行的 CLI 也不同。

现在首先让我们看看我的项目结构。

我的 launchSettings.json 中的代码

{
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "http://localhost:40088/",
      "sslPort": 0
    }
  },
  "profiles": {
    "Development": {
      "commandName": "Project",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "Azuredev": {
      "commandName": "Project",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Azuredev"
      }
    }
  }
}

launch.json 中的代码

{
"version": "0.2.0",
"configurations": [
        {
            "name": ".NET Core Launch (web)",
            "type": "coreclr",
            "request": "launch",
            "preLaunchTask": "build",
            // If you have changed target frameworks, make sure to update the program path.
            "program": "${workspaceRoot}/my.api/bin/Debug/netcoreapp2.0/my.api.dll",
            "args": [],
            "cwd": "${workspaceRoot}/my.api",
            "stopAtEntry": false,
            "requireExactSource": false,
            "internalConsoleOptions": "openOnSessionStart",
            "launchBrowser": {
                "enabled": true,
                "args": "${auto-detect-url}",
                "windows": {
                    "command": "cmd.exe",
                    "args": "/C start ${auto-detect-url}"
                },
                "osx": {
                    "command": "open"
                },
                "linux": {
                    "command": "xdg-open"
                }
            },
            "sourceFileMap": {
                "/Views": "${workspaceRoot}/Views"
            }
        },
        {
            "name": ".NET Core Attach",
            "type": "coreclr",
            "request": "attach",
            "processId": "${command:pickProcess}"
        }
    ]
}

startup.cs

    public IConfigurationRoot Configuration { get; }

    public Startup(IHostingEnvironment env)
    {
        var builder = new ConfigurationBuilder()
            .SetBasePath(env.ContentRootPath)
            .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
            .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: true)
            .AddEnvironmentVariables();

        Configuration = builder.Build();

        this.HostingEnvironment = env;
    }

在所有这些更改之后，我的 API 在 F5 调试选项和 CLI 终端上都可以正常工作。

要从命令行启动应用程序，请使用以下关键字：

dotnet run --launch-profile "Development"

或

dotnet run --launch-profile "Azuredev"

Answer 4

对于.NET Core 3.1，恰好需要添加：

.AddCommandLine(args)

到 Program.cs 中的 ConfigurationBuilder

为

dotnet run --environment "Development"

工作（切换 ASP.NET Core 环境）。

Answer 5

打开Powershell，到达项目位置

首先使用命令设置环境变量

$Env:ASPNETCORE_ENVIRONMENT = "Qa"

从电源外壳运行应用程序 dotnet run --no-launch-profile