微信公众平台开发——新增素材

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接口详情：微信公众平台新增永久素材
新增永久图文素材请求接口，POST数据就能实现，这里主要记录下C#如何通过Form表单上传文件（图片，音频，视频等）

请求接口

		/// 

        /// FORM表单POST方式上传一个多媒体文件
        /// 
        /// 请求地址
        /// 文件类型
        /// 文件名
        /// 文件流
        /// 为视频文件
        /// 视频文件标题
        /// 视频文件描述
        /// 
        /// 
        public static string HttpRequestPostMedia(string url, string typeName, string fileName, Stream stream,bool isVideo = false, string title = "",string introduction ="", string encoding = "UTF-8")
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "POST";
            request.Timeout = 10000;
            var postStream = new MemoryStream();
            #region 处理Form表单文件上传
            //通过表单上传文件
            string boundary = "----" + DateTime.Now.Ticks.ToString("x");
           
            string formdataTemplate = "\r\n--" + boundary + "\r\nContent-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: application/octet-stream\r\n\r\n";
           
             var formdata = string.Format(formdataTemplate, typeName, fileName);
             var formdataStr = postStream.Length == 0 ? formdata.Substring(2, formdata.Length - 2) : formdata;//第一行换行
             var formdataBytes = Encoding.ASCII.GetBytes(formdataStr);
             postStream.Write(formdataBytes, 0, formdataBytes.Length);
                
             //写入文件
             byte[] buffer = new byte[1024];
             int bytesRead = 0;
             while ((bytesRead = stream.Read(buffer, 0, buffer.Length)) != 0)
             {
                 postStream.Write(buffer, 0, bytesRead);
             }
             //视频文件添加请求体
             if (isVideo)
             {
                 var desStr = string.Format("{{\"title\":\"{0}\", \"introduction\":\"{1}\"}}", title, introduction);
                 var formdataStr2 = "\r\n--" + boundary + "\r\n" + "Content-Disposition: form-data; name=\"description\";\r\n\r\n" + desStr;
                 var formdataBytes2 = Encoding.ASCII.GetBytes(formdataStr2);
                 postStream.Write(formdataBytes2, 0, formdataBytes2.Length);
             }

            //结尾
            var footer = Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n");
            postStream.Write(footer, 0, footer.Length);
            request.ContentType = string.Format("multipart/form-data; boundary={0}", boundary);
            #endregion

            request.ContentLength = postStream != null ? postStream.Length : 0;
            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";

            #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);
                }

                postStream.Close();//关闭文件访问
            }
            #endregion

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            using (Stream responseStream = response.GetResponseStream())
            {
                using (StreamReader myStreamReader = new StreamReader(responseStream, Encoding.GetEncoding(encoding)))
                {
                    string retString = myStreamReader.ReadToEnd();
                    return retString;
                }
            }
        }

接口使用（以图片上传为例）

使用Layui写一个前台上传图片的页面

<div class="layui-card">
    <div class="layui-card-header">上传图片素材</div>
    <div class="layui-card-body">
        <div class="layui-form-item">
            <div class="layui-upload">
                <div class="layui-form-item">
                    <label class="layui-form-label">图片备注</label>
                    <div class="layui-input-inline">
                        <input type="text" name="remark" required lay-verify="required" placeholder="请输入图片备注" autocomplete="off" class="layui-input" id="image-text-m">
                    </div>
                    <div class="layui-form-mid layui-word-aux">(图片小于2M，支持bmp/png/jpeg/jpg/gif格式)</div>
                </div>
                <div class="layui-upload-list">
                    <img class="layui-upload-img" src="~/Sources/bg-image.png" id="image-upload-m">
                </div>
                <button type="button" class="layui-btn" id="image-change-btn-m" style="margin-left:30px;">选择图片</button>
                <button type="button" class="layui-btn" id="image-change-btn-action-m" style="margin-left:30px">开始上传</button>
            </div>
        </div>
    </div>
</div>

js

				upload.render({
                    elem: '#image-change-btn-m',
                    url: '', //上传地址接口
                    data: { 'remark': $('#image-text-m').val(), 'type': "image" },
                    auto: false,
                    bindAction: '#image-change-btn-action-m',//上传按钮
                    size: 2047,
                    accept: 'file',//限制文件大小
                    exts: 'bmp|png|jpeg|jpg|gif',//bmp/png/jpeg/jpg/gif //限制文件类型
                    choose: function (obj) {
                            obj.preview(function (index, file, result) {
                                $('#image-upload-m').attr('src', result);  //展示图片
                            });
                    },
                    before: function (obj) {
                        this.data.remark = $('#image-text-m').val();
                        layer.msg('上传中，请稍候...', { icon: 16, time: 1000, shade: 0 });
                        setTimeout(function () {
                        }, 1000);
                    },
                    done: function (res) {
                        if (res.Message == "ok") {
                            layer.alert("素材添加成功", {
                                icon: 1,
                                shadeClose: false,
                                anim: 1,
                                btn: ['知道了']
                            }, function (index) {
                                layer.close(index);
                                location.reload();
                            });
                        } else {
                            layer.alert(res.Message, {
                                icon: 2,
                                shadeClose: false,
                                anim: 1,
                                btn: ['知道了']
                            });
                        }
                    },
                    error: function (err) {
                    }
                });

使用HttpRequestPostMedia方法

HttpPostedFile file = HttpContext.Current.Request.Files["file"];//获取http传输的文件
var remark = HttpContext.Current.Request.Form[0].ToString();//备注
var type = HttpContext.Current.Request.Form[1].ToString();//文件类型
Stream inputStream = file.InputStream;
var data = WXMediaMethod.UploadMedia("https://api.weixin.qq.com/cgi-bin/material/add_material", accessToken, type, "media", file.FileName, inputStream); //data 为微信返回

UploadMedia方法

public static string UploadMedia(string url, string accessToken, string type, string fileType, string fileName, Stream file,bool isVideo = false, string title = "",string introduction="")
{
    var postUrl = string.Format(url + "?access_token={0}&type={1}", accessToken, type);
	var data = HttpMethod.HttpRequestPostMedia(postUrl, fileType, fileName, file, isVideo,title,introduction);
	return data;
 }

效果展示

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博主MarkDown用的不熟练，排版不是很好，大家见谅。
目前是在做微信公众平台的后台管理系统，走过很多微信接口的坑