/// <summary>  /// 使用Post方法获取字符串结果  /// </summary>  /// <param name="url"></param>  /// <param name="formItems">Post表单内容</param>  /// <param name="cookieContainer"></param>  /// <param name="timeOut">默认20秒</param>  /// <param name="encoding">响应内容的编码类型（默认utf-8）</param>  /// <returns></returns>  public static ResultData PostForm(string url, List<FormItemModel> formItems, CookieContainer cookieContainer = null, string refererUrl = null, Encoding encoding = null, int timeOut = 20000){//try//{HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);#region 初始化请求对象  request.Method = "POST";request.Timeout = timeOut;request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8";request.KeepAlive = true;request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.57 Safari/537.36";if (!string.IsNullOrEmpty(refererUrl))request.Referer = refererUrl;if (cookieContainer != null)request.CookieContainer = cookieContainer;#endregionstring boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x");//分隔符  request.ContentType = string.Format("multipart/form-data; boundary={0}", boundary);//请求流  var postStream = new MemoryStream();#region 处理Form表单请求内容  //是否用Form上传文件  var formUploadFile = formItems != null && formItems.Count > 0;if (formUploadFile){//文件数据模板  string fileFormdataTemplate = "--" + boundary + "\r\nContent-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"" + "\r\nContent-Type: \"{2}\"" + "\r\n\r\n";//图片数据模板string picFormdataTemplate = "--" + boundary + "\r\nContent-Disposition: form-data; name=\"{0}\";filename=\"{1}\"\r\nContent-Type:\"{2}\"\r\n\r\n";//文本数据模板  string dataFormdataTemplate = "--" + boundary + "\r\nContent-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}\r\n";foreach (var item in formItems){string formdata = null;switch (item.formItemType){case FormitemTypeEnum.文件://上传文件  formdata = string.Format(fileFormdataTemplate,item.Key, //表单键
                                item.FileName,item.Value);break;case FormitemTypeEnum.图片://上传图片formdata = string.Format(picFormdataTemplate,item.Key, //表单键
                                item.FileName,item.Value);break;case FormitemTypeEnum.文本:default://上传文本  formdata = string.Format(dataFormdataTemplate,item.Key,item.Value);break;}//统一处理  byte[] formdataBytes = null;//第一行不需要换行  //if (postStream.Length == 0)//    formdataBytes = Encoding.UTF8.GetBytes(formdata.Substring(2, formdata.Length - 2));//elseformdataBytes = Encoding.UTF8.GetBytes(formdata);postStream.Write(formdataBytes, 0, formdataBytes.Length);//写入文件内容  if (item.FileContent != null && item.FileContent.Length > 0){using (var stream = item.FileContent){byte[] buffer = new byte[1024];int bytesRead = 0;while ((bytesRead = stream.Read(buffer, 0, buffer.Length)) != 0){postStream.Write(buffer, 0, bytesRead);}}byte[] imgbyteend = Encoding.UTF8.GetBytes("\r\n");postStream.Write(imgbyteend, 0, imgbyteend.Length);}}//结尾  var footer = Encoding.UTF8.GetBytes("\r\n--" + boundary + "--\r\n");postStream.Write(footer, 0, footer.Length);}else{request.ContentType = "application/x-www-form-urlencoded";}#endregionrequest.ContentLength = postStream.Length;#region 输入二进制流  if (postStream != null){postStream.Position = 0;//直接写入流  Stream requestStream = request.GetRequestStream();byte[] buffer = new byte[1024];int bytesRead = 0;while ((bytesRead = postStream.Read(buffer, 0, buffer.Length)) != 0){requestStream.Write(buffer, 0, bytesRead);}////debug//postStream.Seek(0, SeekOrigin.Begin);//StreamReader sr = new StreamReader(postStream);//var postStr = sr.ReadToEnd();postStream.Close();//关闭文件访问
            }#endregionHttpWebResponse response = (HttpWebResponse)request.GetResponse();if (cookieContainer != null){response.Cookies = cookieContainer.GetCookies(response.ResponseUri);}using (Stream responseStream = response.GetResponseStream()){using (StreamReader myStreamReader = new StreamReader(responseStream, encoding ?? Encoding.UTF8)){string retString = myStreamReader.ReadToEnd();ZY_MicronewsResult mresult = JsonConvert.DeserializeObject<ZY_MicronewsResult>(retString);if (!string.IsNullOrEmpty(mresult.response)){return ResultData.Access();}else{return ResultData.Fail(mresult.error);}}}//}//catch (Exception ex)//{//    return ResultData.Fail(ex.Message);//}}

/// <summary>  /// 表单数据项  /// </summary>  public class FormItemModel{public FormitemTypeEnum formItemType { get; set; } = FormitemTypeEnum.文本;/// <summary>  /// 表单键，request["key"]  /// </summary>  public string Key { set; get; }/// <summary>  /// 表单值,上传文件时忽略，request["key"].value/// 格式：application/octet-stream/// </summary>  public string Value { set; get; }public byte[] pic_bytes { get; set; }/// <summary>  /// 是否是文件  /// </summary>  public bool IsFile{get{if (FileContent == null || FileContent.Length == 0)return false;if (FileContent != null && FileContent.Length > 0 && string.IsNullOrWhiteSpace(FileName))throw new Exception("上传文件时 FileName 属性值不能为空");return true;}}/// <summary>  /// 上传的文件名  /// </summary>  public string FileName { set; get; }/// <summary>  /// 上传的文件内容  /// </summary>  public Stream FileContent { set; get; }/// <summary>/// 获取上传文件Model/// </summary>/// <param name="key">名称</param>/// <param name="value">内容</param>/// <returns></returns>public static FormItemModel GetTextModel(string key, string value){var model = new Model.Common.FormItemModel{Key = key,Value = value,formItemType = Model.Common.FormitemTypeEnum.文本};return model;}/// <summary>/// 获取上传文件Model/// </summary>/// <param name="url">url路径</param>/// <returns></returns>public static FormItemModel GetFileModel(string url){Uri uri = null;try{uri = new Uri(url);}catch{return null;}var bit = Model.Common.DownloadImg(uri.AbsoluteUri);System.IO.MemoryStream memo = new System.IO.MemoryStream();bit.Save(memo, System.Drawing.Imaging.ImageFormat.Jpeg);memo.Position = 0;var model = new Model.Common.FormItemModel{Key = "file",Value = "application/octet-stream",FileName = Path.GetFileName(uri.AbsoluteUri),formItemType = Model.Common.FormitemTypeEnum.文件,FileContent = memo};return model;}/// <summary>/// 获取上传图片Model/// </summary>/// <param name="url">url路径</param>/// <returns></returns>public static FormItemModel GetImgModel(string key, string url){Uri uri = null;try{uri = new Uri(url);}catch{return null;}var bit = Model.Common.DownloadImg(uri.AbsoluteUri);System.IO.MemoryStream memo = new System.IO.MemoryStream();bit.Save(memo, System.Drawing.Imaging.ImageFormat.Jpeg);memo.Position = 0;var model = new Model.Common.FormItemModel{Key = key,Value = "application/octet-stream",FileName = Path.GetFileName(uri.AbsoluteUri),formItemType = Model.Common.FormitemTypeEnum.图片,FileContent = memo};return model;}/// <summary>/// 获取上传图片Model/// </summary>/// <param name="key">名称</param>/// <param name="fileName">文件名</param>/// <param name="stream">文件流</param>/// <returns></returns>public static FormItemModel GetImgModel(string key, string fileName, Stream stream){stream.Position = 0;var model = new Model.Common.FormItemModel{Key = key,Value = "application/octet-stream",FileName = fileName,formItemType = Model.Common.FormitemTypeEnum.图片,FileContent = stream};return model;}}/// <summary>/// Form上传类型/// </summary>public enum FormitemTypeEnum{文本 = 0,文件 = 1,图片 = 2}

string url = "http://xxxxx.com";List<Model.Common.FormItemModel> formItems = new List<Model.Common.FormItemModel>();formItems.Add(Model.Common.FormItemModel.GetTextModel("visible", "-1"));　　//文本参数var imgs = model_MicroNews.MicroNews_imgurl.ToList();for (int i = 0; i < imgs.Count; i++){var img = imgs[i];formItems.Add(Model.Common.FormItemModel.GetImgModel("pic_" + (i + 1), "pic_" + (i + 1) + ".jpeg", img.stream));　　//图片}var result = Model.Common.PostForm(url, formItems);