string bline = "---------------------------" + DateTime.Now.Ticks.ToString("x"); var wc = new WebClient(); wc.Headers.Add("Content-Type", "multipart/form-data; boundary=" + bline); List<byte> bss = new List<byte>(); bss.AddRange(Encoding.UTF8.GetBytes(String.Format("--" + bline + " Content-Disposition: form-data; name="{0}" {1} ", "user_id", "249"))); bss.AddRange(Encoding.UTF8.GetBytes(String.Format("--" + bline + " Content-Disposition: form-data; name="{0}" {1} ", "content", "开始测试接口。"))); bss.AddRange(Encoding.UTF8.GetBytes(String.Format("--" + bline + " Content-Disposition: form-data; name="{0}" {1} ", "visible", "-1"))); //图1 { bss.AddRange(Encoding.UTF8.GetBytes(String.Format("--" + bline + " Content-Disposition: form-data; name="{0}" ", "pic_1"))); bss.AddRange(File.ReadAllBytes("d:\1.jpg")); bss.AddRange(Encoding.UTF8.GetBytes(" ")); } //图2 { bss.AddRange(Encoding.UTF8.GetBytes(String.Format("--" + bline + " Content-Disposition: form-data; name="{0}" ", "pic_2"))); bss.AddRange(File.ReadAllBytes("d:\2.jpg")); bss.AddRange(Encoding.UTF8.GetBytes(" ")); } bss.AddRange(Encoding.UTF8.GetBytes("--" + bline + "-- ")); byte[] rbs = wc.UploadData("接收地址", bss.ToArray()); string s = Encoding.UTF8.GetString(rbs); Debug.WriteLine(s);