Csharp 每个http请求需要60秒，为什么

下面的代码块说明了如何使用TCP和网络流发送HTTP请求.但是，无论应用什么过滤，每个请求都会持续消耗60秒的平均时间.无论是单个数据还是数千个数据到达，延迟都保持不变.为什么它会持续60秒？是否没有缩短此时间段的选项，或者是否有无需等待即可立即获取数据的设置？

// Specify the server and port
string server = "xxx.com";
int port = 80;

// Specify the HTTP request
string httpRequest = "POST /ApiPrefixNameHere/ControllerNameHere/ActionNameHere HTTP/1.1\r\nHost: xxx.com\r\naccept: text/plain\r\nContent-Type: application/json-patch+json\r\nContent-Length: 27\r\n\r\n{\"ParameterNameHere\":\"1580\"}";

// Create a TcpClient
using (TcpClient tcpClient = new())
{
    await tcpClient.ConnectAsync(server, port);

    using (NetworkStream networkStream = tcpClient.GetStream())
    using (StreamWriter writer = new(networkStream, Encoding.ASCII))
    using (StreamReader reader = new(networkStream, Encoding.ASCII))
    {
        // Send the HTTP request
        await writer.WriteAsync(httpRequest);
        await writer.FlushAsync();

        // Read the response
        string response = await reader.ReadToEndAsync();

        // Display the response
        Console.WriteLine("Response: " + response);
    }
}

我对这些老方法不太熟悉.我try 了NoDelay()和各种超时配置等策略，但没有一个被证明是有效的.

首先感谢您的帮助.

在@jonskeet的回答后编辑

// add `Connection: close`
string httpRequest = "POST /ApiPrefixNameHere/ControllerNameHere/ActionNameHere HTTP/1.1\r\nHost: xxx.com\r\naccept: text/plain\r\nContent-Type: application/json-patch+json\r\nConnection: close\r\nContent-Length: 28\r\n\r\n{\"ParameterNameHere\":\"1580\"}";