HttpWebRequest(System.Net)模拟HTTP发送POST

相关参考网上很多,但需要理解并转成自己的情况

public static string HttpWebRequestPost(string url, string param)
{
    HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);
    Encoding encoding = Encoding.UTF8;
    byte[] byteArray = Encoding.ASCII.GetBytes(param);
    string responseData = String.Empty;
    req.Method = "POST";
    req.ContentType = "application/x-www-form-urlencoded";
    req.ContentLength = byteArray.Length;

    using (Stream reqStream = req.GetRequestStream())
    {
        reqStream.Write(byteArray, 0, byteArray.Length);
    }
    using (HttpWebResponse response = (HttpWebResponse)req.GetResponse())
    {
        using (StreamReader reader = new StreamReader(response.GetResponseStream(), encoding))
        {
            responseData = reader.ReadToEnd();
        }
        return responseData;
    }
}

1.第1行param:需要发送的POST参数,需要和对应接收端约定好相应的格式,如本实例为 random=abc&check=faa5bff8a65e359ea863ca1e ,查参考代码时在stackoverflow.com上看到POST要传送到数据格式是这样的 string data = "{"service":"absence.list", "company_id":3}"; 

2.第5行是注意点需要将发送到数据转成byte[],这里有一个坑,需要使用对应Encoding工具,推测也是和接收请求的服务端相对应的,这里使用了Encoding.ASCII.GetBytes(param);参考代码中大多是使用了UTF8Encoding对象的.GetBytes(data)方法.

相关参考:获取UTF8Encoding对象两种coding

UTF8Encoding enc = new UTF8Encoding(); byte[] buf = enc.GetBytes(data);
//方式二
byte[] buf = System.Text.Encoding.GetEncoding("utf-8").GetBytes(RequestPara);

3.第8行需要根据实际情况调整,其它参考值xxx.ContentType = "application/json; charset=UTF-8";

4.11至15行HttpWebRequest发送POST请求的必须套路,即将发送参数写入输出流,看到不少大同小异的编程风格

5. 第16行req.GetResponse()核心方法,将请求真正发送出去,然后从响应流中读取数据

附GET请求

public string HttpWebRequestGet(string url, string param)
{
    param = param.IndexOf('?') > -1 ? (param) : ("?" + param);

    HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url + param);
    Encoding encoding = Encoding.UTF8;
    string responseData = String.Empty;
    req.Method = "GET";
    using (HttpWebResponse response = (HttpWebResponse)req.GetResponse())
    {
        using (StreamReader reader = new StreamReader(response.GetResponseStream(), encoding))
        {
            responseData = reader.ReadToEnd();
        }
        return responseData;
    }
}

end