从这个环节，就有了更好的解决方案。

在Startup.cs中，我们需要添加service-

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

然后在任何控制器或任何地方，我们都需要像这样通过依赖注入来使用它

private IHttpContextAccessor HttpContextAccessor { get; }

public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options, IWebHostEnvironment env, IHttpContextAccessor httpContextAccessor)
        : base(options)
{
    Environment = env;
    HttpContextAccessor = httpContextAccessor;
    //this.Database.EnsureCreated();
}

然后得到这样的IP

IPAddress userIp = HttpContextAccessor.HttpContext.Connection.RemoteIpAddress;

要在。net Core中获取IP地址和主机名，在控制器中输入以下代码:

var addlist = Dns.GetHostEntry(Dns.GetHostName());
string GetHostName = addlist.HostName.ToString();
string GetIPV6 = addlist.AddressList[0].ToString();
string GetIPV4 = addlist.AddressList[1].ToString();

从这个环节，就有了更好的解决方案。

在Startup.cs中，我们需要添加service-

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

然后在任何控制器或任何地方，我们都需要像这样通过依赖注入来使用它

private IHttpContextAccessor HttpContextAccessor { get; }

public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options, IWebHostEnvironment env, IHttpContextAccessor httpContextAccessor)
        : base(options)
{
    Environment = env;
    HttpContextAccessor = httpContextAccessor;
    //this.Database.EnsureCreated();
}

然后得到这样的IP

IPAddress userIp = HttpContextAccessor.HttpContext.Connection.RemoteIpAddress;

试试这个:

string remoteHost = $"{httpContext.Connection.RemoteIpAddress}:{httpContext.Connection.RemotePort}";

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Http.Features;

public string GetClientIPAddress(HttpContext context)
    {
        string ip = string.Empty;
if (!string.IsNullOrEmpty(context.Request.Headers["X-Forwarded-For"]))
        {
            ip = context.Request.Headers["X-Forwarded-For"];
        }
        else
        {
            ip = context.Request.HttpContext.Features.Get<IHttpConnectionFeature>().RemoteIpAddress.ToString();
        }
        return ip;
    }

你想获取Ip地址;

GetClientIPAddress(HttpContext);

var remoteIpAddress = HttpContext.Features.Get<IHttpConnectionFeature>()?.RemoteIpAddress;