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);

@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;
}

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

可以添加一些回退逻辑来处理负载均衡器的存在。

此外，通过检查，即使没有负载均衡器，X-Forwarded-For报头也会被设置(可能是因为额外的Kestrel层?):

public string GetRequestIP(bool tryUseXForwardHeader = true)
{
    string ip = null;

    // todo support new "Forwarded" header (2014) https://en.wikipedia.org/wiki/X-Forwarded-For

    // X-Forwarded-For (csv list):  Using the First entry in the list seems to work
    // for 99% of cases however it has been suggested that a better (although tedious)
    // approach might be to read each IP from right to left and use the first public IP.
    // http://stackoverflow.com/a/43554000/538763
    //
    if (tryUseXForwardHeader)
        ip = GetHeaderValueAs<string>("X-Forwarded-For").SplitCsv().FirstOrDefault();

    // RemoteIpAddress is always null in DNX RC1 Update1 (bug).
    if (ip.IsNullOrWhitespace() && _httpContextAccessor.HttpContext?.Connection?.RemoteIpAddress != null)
        ip = _httpContextAccessor.HttpContext.Connection.RemoteIpAddress.ToString();

    if (ip.IsNullOrWhitespace())
        ip = GetHeaderValueAs<string>("REMOTE_ADDR");

    // _httpContextAccessor.HttpContext?.Request?.Host this is the local host.

    if (ip.IsNullOrWhitespace())
        throw new Exception("Unable to determine caller's IP.");

    return ip;
}

public T GetHeaderValueAs<T>(string headerName)
{
    StringValues values;

    if (_httpContextAccessor.HttpContext?.Request?.Headers?.TryGetValue(headerName, out values) ?? false)
    {
        string rawValues = values.ToString();   // writes out as Csv when there are multiple.

        if (!rawValues.IsNullOrWhitespace())
            return (T)Convert.ChangeType(values.ToString(), typeof(T));
    }
    return default(T);
}

public static List<string> SplitCsv(this string csvList, bool nullOrWhitespaceInputReturnsNull = false)
{
    if (string.IsNullOrWhiteSpace(csvList))
        return nullOrWhitespaceInputReturnsNull ? null : new List<string>();

    return csvList
        .TrimEnd(',')
        .Split(',')
        .AsEnumerable<string>()
        .Select(s => s.Trim())
        .ToList();
}

public static bool IsNullOrWhitespace(this string s)
{
    return String.IsNullOrWhiteSpace(s);
}

假设_httpContextAccessor通过DI提供。

API已经更新。不知道它什么时候改变了，但根据达米安·爱德华兹在12月底的说法，你现在可以这样做:

var remoteIpAddress = request.HttpContext.Connection.RemoteIpAddress;

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