如果你需要在你的代码库中某个不容易访问IHostingEnvironment的地方测试这个，另一个简单的方法是这样做的:

bool isDevelopment = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT") == "Development";

你可以很容易地在ConfigureServices中访问它，只是在Startup方法期间将它持久化到一个属性，该方法首先被调用并将其传递进来，然后你可以从ConfigureServices访问该属性。

public Startup(IWebHostEnvironment env, IApplicationEnvironment appEnv)
{
    ...your code here...
    CurrentEnvironment = env;
}

private IWebHostEnvironment CurrentEnvironment{ get; set; } 
 
public void ConfigureServices(IServiceCollection services)
{
    string envName = CurrentEnvironment.EnvironmentName;
    ... your code here...
}

在NET6中，启动和程序合并为一个文件，启动中不再有ConfigureServices方法。现在你可以简单地使用

builder.Environment.IsProduction() 
builder.Environment.IsStaging()
builder.Environment.IsDevelopment()

就在第一行之后

var builder = WebApplication.CreateBuilder(args);

来自文档

Configure和ConfigureServices支持特定环境的版本 配置{EnvironmentName}和配置{EnvironmentName}形式的服务:

你可以这样做……

public void ConfigureProductionServices(IServiceCollection services)
{
    ConfigureCommonServices(services);
    
    //Services only for production
    services.Configure();
}

public void ConfigureDevelopmentServices(IServiceCollection services)
{
    ConfigureCommonServices(services);
    
    //Services only for development
    services.Configure();
}

public void ConfigureStagingServices(IServiceCollection services)
{
    ConfigureCommonServices(services);
    
    //Services only for staging
    services.Configure();
}

private void ConfigureCommonServices(IServiceCollection services)
{
    //Services common to each environment
}

由于还没有完整的复制和粘贴解决方案，基于Joe Audette的回答:

public IWebHostEnvironment Environment { get; }

public Startup(IWebHostEnvironment environment, IConfiguration configuration)
{
   Environment = environment;
   ...
}

public void ConfigureServices(IServiceCollection services)
{
   if (Environment.IsDevelopment())
   {
       // Do something
   }else{
       // Do something
   }
   ...
}

我想在我的服务中加入这种环境。这真的很容易做到!我只是像这样把它注入到构造函数中:

    private readonly IHostingEnvironment _hostingEnvironment;

    public MyEmailService(IHostingEnvironment hostingEnvironment)
    {
        _hostingEnvironment = hostingEnvironment;
    }

现在在稍后的代码中，我可以这样做:

if (_hostingEnvironment.IsProduction()) {
    // really send the email.
}
else {
    // send the email to the test queue.
}

编辑:

上面的代码是用于。net Core 2的。对于版本3，您将使用IWebHostEnvironment。