@crokusek回答的简短版本

public string GetUserIP(HttpRequest req)
{
    var ip = req.Headers["X-Forwarded-For"].FirstOrDefault();

    if (!string.IsNullOrWhiteSpace(ip)) ip = ip.Split(',')[0];

    if (string.IsNullOrWhiteSpace(ip)) ip = Convert.ToString(req.HttpContext.Connection.RemoteIpAddress);

    if (string.IsNullOrWhiteSpace(ip)) ip = req.Headers["REMOTE_ADDR"].FirstOrDefault();

    return ip;
}

我发现，你们中的一些人发现你们得到的IP地址是:::1或0.0.0.1

这是一个问题，因为你试图从你自己的机器获取IP，而c#试图返回IPv6的混乱。

所以，我实现了来自@Johna (https://stackoverflow.com/a/41335701/812720)和@David (https://stackoverflow.com/a/8597351/812720)的答案，感谢他们!

下面是解决方案:

add Microsoft.AspNetCore.HttpOverrides Package in your References (Dependencies/Packages) add this line in Startup.cs public void Configure(IApplicationBuilder app, IHostingEnvironment env) { // your current code // start code to add // to get ip address app.UseForwardedHeaders(new ForwardedHeadersOptions { ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto }); // end code to add } to get IPAddress, use this code in any of your Controller.cs IPAddress remoteIpAddress = Request.HttpContext.Connection.RemoteIpAddress; string result = ""; if (remoteIpAddress != null) { // If we got an IPV6 address, then we need to ask the network for the IPV4 address // This usually only happens when the browser is on the same machine as the server. if (remoteIpAddress.AddressFamily == System.Net.Sockets.AddressFamily.InterNetworkV6) { remoteIpAddress = System.Net.Dns.GetHostEntry(remoteIpAddress).AddressList .First(x => x.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork); } result = remoteIpAddress.ToString(); }

现在你可以从remoteIpAddress或result获取IPv4地址

这适用于我(DotNetCore 2.1)

[HttpGet]
public string Get() 
{
    var remoteIpAddress = HttpContext.Connection.RemoteIpAddress;
    return remoteIpAddress.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;

根据官方文档，如果你使用Apache或Nginx集成，以下代码应该添加到启动。ConfigureServices方法。

// using Microsoft.AspNetCore.HttpOverrides;

    services.Configure<ForwardedHeadersOptions>(options =>
    {
        options.ForwardedHeaders = ForwardedHeaders.XForwardedFor | 
            ForwardedHeaders.XForwardedProto;
        // Only loopback proxies are allowed by default.
        // Clear that restriction because forwarders are enabled by explicit 
        // configuration.
        options.KnownNetworks.Clear();
        options.KnownProxies.Clear();
    });

最重要的是，在配置方法中使用

app.UseForwardedHeaders();

进一步假设在nginx conf文件中，在一个位置内，使用

proxy_set_header   Host $host;
proxy_set_header   X-Real-IP $remote_addr;
proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header   X-Forwarded-Host $server_name;

现在X-Forwarded-For中的第一个条目将是真正的客户端IP。

重要:如果你想保护应用程序，不允许攻击者注入x - forward - for，请阅读这个答案。

请参见转发Linux和非iis反向代理方案、配置Nginx和处理无效报头

首先，在。net Core 1.0中 使用Microsoft.AspNetCore.Http.Features添加;到控制器 然后里面的相关方法:

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

我读了其他几个答案，因为它使用了小写的httpContext，导致VS使用Microsoft.AspNetCore添加。Http，而不是适当的使用，或与HttpContext(编译器也是误导)。