Ta的回复 ：private void Button1_Click(object sender, EventArgs e) { byte[] bet = returnbyte("E:\\IMG_4146.JPG");//图片转换成二进制 pictureBox1.Image = ReturnPhoto(bet); string strUrl = "http://localhost:24401/"; string strResult = this.GetPostString(strUrl, bet); } public string GetPostString(string url, byte[] data) { try { byte[] postBytes = data; HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(url); myRequest.Method = "POST"; myRequest.ContentType = "text/html"; myRequest.ContentLength = postBytes.Length; myRequest.Proxy = null; Stream newStream = myRequest.GetRequestStream(); newStream.Write(postBytes, 0, postBytes.Length); newStream.Close(); // Get response HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse(); using (StreamReader reader = new StreamReader(myResponse.GetResponseStream(), Encoding.GetEncoding("utf-8"))) { string content = reader.ReadToEnd(); return content; } } catch (System.Exception ex) { return ex.Message; } } public System.Drawing.Image ReturnPhoto(byte[] streamByte) { System.IO.MemoryStream ms = new System.IO.MemoryStream(streamByte); System.Drawing.Image img = System.Drawing.Image.FromStream(ms); return img; } /// /// 图片路径转二进制 /// /// /// public byte[] returnbyte(string strpath) { // 以二进制方式读文件 FileStream fsMyfile = new FileStream(strpath, FileMode.OpenOrCreate, FileAccess.ReadWrite); // 创建一个二进制数据流读入器，和打开的文件关联 BinaryReader brMyfile = new BinaryReader(fsMyfile); // 把文件指针重新定位到文件的开始 brMyfile.BaseStream.Seek(0, SeekOrigin.Begin); byte[] bytes = brMyfile.ReadBytes(Convert.ToInt32(fsMyfile.Length.ToString())); // 关闭以上new的各个对象 brMyfile.Close(); return bytes; }