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ASP.net Core中的多环境

分类: Asp.net Core入门 ◆ 标签: #Asp.Net core基础 #基础 #Web ◆ 发布于: 2023-06-04 20:28:35

我们这里讲的环境指的是ASP.net Core应用运行的runtime环境。这些环境您可以自定义环境名称，并根据这些环境来设置不同的设置，但是有三个环境以及用来命名的环境的名称是ASP.net Core定义的：

Development: 开发环境
Staging: 预发布环境
Produciton: 产线环境

ASP.net Core生成的程序模板，也会根据这三个环境设定一些仅仅有该环境才有的特性，例如：

在Development开发环境下，启用中间件UseDeveloperExceptionPage
在预发布环境和产线环境，启用中间件UseExceptionHandler

注意在Startup类中的Configure方法可以注入IWebHostEnvironment实例，用于环境的判断。也可以通过构造函数注入。

例如：

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }

    if (env.IsProduction() || env.IsStaging() || env.IsEnvironment("Staging_2"))
    {
        app.UseExceptionHandler("/Error");
    }

    app.UseHttpsRedirection();
    app.UseStaticFiles();

    app.UseRouting();

    app.UseAuthorization();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapRazorPages();
    });
}

使用`Environment Tag Help`

<environment include="Development">
    <div>The effective tag is: &lt;environment include="Development"&gt;</div>
</environment>
<environment exclude="Development">
    <div>The effective tag is: &lt;environment exclude="Development"&gt;</div>
</environment>
<environment include="Staging,Development,Staging_2">
    <div>
        The effective tag is:
        &lt;environment include="Staging,Development,Staging_2"&gt;
    </div>
</environment>

设定环境

通过环境变量

一般情况是通过环境变量来设置环境：

ASPNETCORE_ENVIRONMENT

开发模式和`launchSettings.json`

当且仅当应用为开发模式，而且是在本地，dotnet可以使用Properties\launchSettings.json 来设置环境变量。例如：

{
  "iisSettings": {
    "windowsAuthentication": false, 
    "anonymousAuthentication": true, 
    "iisExpress": {
      "applicationUrl": "http://localhost:64645",
      "sslPort": 44366
    }
  },
  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "EnvironmentsSample": {
      "commandName": "Project",
      "launchBrowser": true,
      "applicationUrl": "https://localhost:5001;http://localhost:5000",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

`Startup`中使用环境

public class Startup
{
    public Startup(IConfiguration configuration, IWebHostEnvironment env)
    {
        Configuration = configuration;
        _env = env;
    }

    public IConfiguration Configuration { get; }
    private readonly IWebHostEnvironment _env;

    public void ConfigureServices(IServiceCollection services)
    {
        if (_env.IsDevelopment())
        {
            Console.WriteLine(_env.EnvironmentName);
        }
        else if (_env.IsStaging())
        {
            Console.WriteLine(_env.EnvironmentName);
        }
        else
        {
            Console.WriteLine("Not dev or staging");
        }

        services.AddRazorPages();
    }

    public void Configure(IApplicationBuilder app)
    {
        if (_env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler("/Error");
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseStaticFiles();

        app.UseRouting();

        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapRazorPages();
        });
    }
}

`Startup`类可以定义多个环境

public class StartupDevelopment
{
    public StartupDevelopment(IConfiguration configuration)
    {
        Configuration = configuration;
        Console.WriteLine(MethodBase.GetCurrentMethod().DeclaringType.Name);
    }

    public IConfiguration Configuration { get; }

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddRazorPages();
    }

    public void Configure(IApplicationBuilder app)
    {
        app.UseDeveloperExceptionPage();

        app.UseHttpsRedirection();
        app.UseStaticFiles();

        app.UseRouting();

        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapRazorPages();
        });
    }
}

public class StartupProduction
{
    public StartupProduction(IConfiguration configuration)
    {
        Configuration = configuration;
        Console.WriteLine(MethodBase.GetCurrentMethod().DeclaringType.Name);
    }

    public IConfiguration Configuration { get; }

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddRazorPages();
    }

    public void Configure(IApplicationBuilder app)
    {

        app.UseExceptionHandler("/Error");
        app.UseHsts();

        app.UseHttpsRedirection();
        app.UseStaticFiles();

        app.UseRouting();

        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapRazorPages();
        });
    }
}

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
        Console.WriteLine(MethodBase.GetCurrentMethod().DeclaringType.Name);
    }

    public IConfiguration Configuration { get; }

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddRazorPages();
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler("/Error");
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseStaticFiles();

        app.UseRouting();

        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapRazorPages();
        });
    }
}

根据环境定义多个Startup类。
需要注意在Programe中初始化用程序集：

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

    public static IHostBuilder CreateHostBuilder(string[] args)
    {
        var assemblyName = typeof(Startup).GetTypeInfo().Assembly.FullName;

        return   Host.CreateDefaultBuilder(args)
            .ConfigureWebHostDefaults(webBuilder =>
            {
                webBuilder.UseStartup(assemblyName);
            });
    }
}

`Startup`类中的多环境方法

ASP.net core中的startup类两个方法支持多个环境命名：

public class Startup
{
    private void StartupConfigureServices(IServiceCollection services)
    {
        services.AddRazorPages();
    }

    public void ConfigureDevelopmentServices(IServiceCollection services)
    {
        MyTrace.TraceMessage();
        StartupConfigureServices(services);
    }

    public void ConfigureStagingServices(IServiceCollection services)
    {
        MyTrace.TraceMessage();
        StartupConfigureServices(services);
    }

    public void ConfigureProductionServices(IServiceCollection services)
    {
        MyTrace.TraceMessage();
        StartupConfigureServices(services);
    }

    public void ConfigureServices(IServiceCollection services)
    {
        MyTrace.TraceMessage();
        StartupConfigureServices(services);
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        MyTrace.TraceMessage();

        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler("/Error");
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseStaticFiles();

        app.UseRouting();

        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapRazorPages();
        });
    }

    public void ConfigureStaging(IApplicationBuilder app, IWebHostEnvironment env)
    {
        MyTrace.TraceMessage();

        app.UseExceptionHandler("/Error");
        app.UseHsts();

        app.UseHttpsRedirection();
        app.UseStaticFiles();

        app.UseRouting();

        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapRazorPages();
        });
    }
}

public static class MyTrace
{
    public static void TraceMessage([CallerMemberName] string memberName = "")
    {
        Console.WriteLine($"Method: {memberName}");
    }
}

使用Environment Tag Help

设定环境

通过环境变量

开发模式和launchSettings.json

Startup中使用环境

Startup类可以定义多个环境

Startup类中的多环境方法

使用`Environment Tag Help`

开发模式和`launchSettings.json`

`Startup`中使用环境

`Startup`类可以定义多个环境

`Startup`类中的多环境方法