[C#] 发送 http 请求

http post 请求 ，参数使用 json 格式

using System.Net;
using System.IO;


public static string PostUrl(string url, string postData)
{
    string result = "";
    byte[] data = Encoding.UTF8.GetBytes(postData);

    HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
    req.Method = "POST";
    req.Timeout = 800;
    req.ContentType = "application/json";
    req.ContentLength = data.Length;

    using (Stream reqStream = req.GetRequestStream())
    {
        reqStream.Write(data, 0, data.Length);
        reqStream.Close();
    }

    HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
    Stream stream = resp.GetResponseStream();

    //获取响应内容
    using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
    {
        result = reader.ReadToEnd();
    }

    return result;
}

用法：

string result = PostUrl("http://127.0.0.1:3000/aesEncrypt", "{\"key\":\"lysm\",\"data\":\"123456\"}");
MessageBox.Show("服务器返回：" + result);

效果：
与 postman 结果相同

---

补充：带 cookie 的 http post 请求（配合服务端 session 使用）

public static string PostUrl(string url, string postData)
{
    string result = "";
    byte[] data = Encoding.UTF8.GetBytes(postData);

    HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
    req.Method = "POST";
    req.Timeout = 800;
    req.ContentType = "application/json";
    req.ContentLength = data.Length;
    req.CookieContainer = myCookieContainer;

    try
    {
        using (Stream reqStream = req.GetRequestStream())
        {
            reqStream.Write(data, 0, data.Length);
            reqStream.Close();
        }

        HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
        resp.Cookies = myCookieContainer.GetCookies(req.RequestUri);
        Stream stream = resp.GetResponseStream();

        //获取响应内容
        using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
        {
            result = reader.ReadToEnd();
        }
    }
    catch
    {
        result = "connect sever failed";
    }

    

    return result;
}