在Blazor应用程序中使用UPnP实现自动端口映射

1. 安装NuGet包

使用Visual Studio的NuGet包管理器安装Open.Nat和Microsoft.Extensions.Logging.Abstractions NuGet包。

2. 创建UPnP服务

创建一个UPnP服务来管理端口映射和取消映射：

using Open.Nat; using Microsoft.Extensions.Logging.Abstractions;

public class UpnpService { private readonly ILogger _logger; private readonly NatDiscoverer _nat;

public UpnpService()
{
    _logger = NullLogger.Instance;
    _nat = new NatDiscoverer();
}

public async Task OpenPort(int port)
{
    var ip = await GetInternalIp();
    var mappings = await _nat.DiscoverDeviceAsync().CreatePortMapAsync(new Mapping(Protocol.Tcp, port, port, 0, ip, true, "MyApp"));
    _logger.LogInformation($"Port {port} mapped to {ip}");
    return mappings;
}

public async Task ClosePort(Mapping mapping)
{
    var device = await _nat.DiscoverDeviceAsync();
    await device.DeletePortMapAsync(mapping);
    _logger.LogInformation($"Port {mapping.PublicPort} unmapped");
}

private async Task GetInternalIp()
{
    using var udpClient = new UdpClient("8.8.8.8", 1);
    return ((IPEndPoint)udpClient.Client.LocalEndPoint).Address;
}

}

3. 在应用程序中使用UPnP服务

在应用程序中使用UpnpService来管理端口映射：

public class IndexModel : PageModel { private readonly UpnpService _upnpService;

public IndexModel(UpnpService upnpService)
{
    _upnpService = upnpService;
}

public async Task OnGet()
{
    var mapping = await _upnpService.OpenPort(5000);
    // Use the mapped port
    ...
    await _upnpService.ClosePort(mapping);
}

}

这是使用Blazor应用程序中的UPnP自动端口映射的基本示例。