C#发送简单的post和get请求（转载）

• POST发送请求及接受响应流程 

1. 根据目标地址址创建HttpWebRequest对象
2. 设置响应的请求参数------Method、ContentType 等
3. 使用HttpWebRequest对象获取请求流并且写入消息体   
4. 使用HttpWebRequest对象获取响应流并读取流中数据(在获取过程中就是发送请求并接受响应)

• GET发送请求及接受响应流程

1. 把目标地址和查询字符串拼接在一起(如果有查询字符串)使用拼接的字符串创建HttpWebRequest对象
2. 设置响应的请求参数------Method、ContentType 等
3. 使用HttpWebRequest对象获取响应流并读取流中数据(在获取过程中就是发送请求并接受响应)

   以下为代码：

        两个请求方法 和读取方法

/// <summary>
/// 发送http post请求
/// </summary>
/// <param name="url">地址</param>
/// <param name="parameters">查询参数集合</param>
/// <returns></returns>
public HttpWebResponse CreatePostHttpResponse(string url, IDictionary<string, string> parameters)
{
    HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;//创建请求对象
    request.Method = "POST";//请求方式
    request.ContentType = "application/x-www-form-urlencoded";//链接类型
    //构造查询字符串
    if (!(parameters == null || parameters.Count == 0))
    {
        StringBuilder buffer = new StringBuilder();
        bool first = true;
        foreach (string key in parameters.Keys)
        {
            if (!first)
            {
                buffer.AppendFormat("&{0}={1}", key, parameters[key]);
            }
            else
            {
                buffer.AppendFormat("{0}={1}", key, parameters[key]);
                first = false;
            }
        }
        byte[] data = Encoding.UTF8.GetBytes(buffer.ToString());
        //写入请求流
        using (Stream stream = request.GetRequestStream())
        {
            stream.Write(data, 0, data.Length);
        }
    }
    return request.GetResponse() as HttpWebResponse;
}
/// <summary>
/// 发送http Get请求
/// </summary>
/// <param name="url"></param>
/// <returns></returns>
public static HttpWebResponse CreateGetHttpResponse(string url)
{
    HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
    request.Method = "GET";
    request.ContentType = "application/x-www-form-urlencoded";//链接类型
    return request.GetResponse() as HttpWebResponse;
}
/// <summary>
/// 从HttpWebResponse对象中提取响应的数据转换为字符串
/// </summary>
/// <param name="webresponse"></param>
/// <returns></returns>
public string GetResponseString(HttpWebResponse webresponse)
{
    using (Stream s = webresponse.GetResponseStream())
    {
        StreamReader reader = new StreamReader(s, Encoding.UTF8);
        return reader.ReadToEnd();
    }
}

　　调用

//post请求并调用
Dictionary<string, string> dic = new Dictionary<string, string>();
dic.Add("id", "4");
textBox1.Text = GetResponseString(CreatePostHttpResponse("https://www.baidu.com/", dic));
//get请求并调用
textBox3.Text = GetResponseString(CreateGetHttpResponse("https://i.cnblogs.com/EditPosts.aspx?opt=1"));

原文地址：https://www.cnblogs.com/cyh1282656849/p/7486262.html