MVC微信浏览器图片上传（img转Base64）

因公司业务需要，需要做一个微信公众号里的图片上传功能，主要用到的技术就是 img转base64 上到服务器

话不多说， 贴代码

• 先看前端显示出来的东西
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• OK 图片不重要，看代码 

 <!--微信图片上传-->
                <section class="logo-license">
                    <div class="half">
                        <div class="uploader">
                            <a class="license">
                                @if (!string.IsNullOrEmpty(Model.ClassImage))
                                {
                                    <img id="img-1" src="@Model.ClassImage" />
                                }
                                else
                                {
                                    <img id="img-1" src="/images/img_01.png" />
                                }

                            </a>
                            <input id="file0" class="file-3" name="imageData" type="file" width="130" height="130" accept="image/*" />
                        </div>
                        <div class="yulan">
                            <img src="" id="img0">
                            <div class="enter">
                                <button class="btn-2 fl">取消</button>
                                <input type="submit" class="btn-3 fr" value="确定" />
                            </div>
                        </div>
                    </div>
                    <div class="clear"></div>
                </section>

再看js代码

 <script>
        var subUrl = "";

        $("#file0").change(function () {
            //获取当前
            var objUrl = getObjectURL(this.files[0]);
            console.log(this.files[0])
            obUrl = objUrl;
            console.log("objUrl = " + objUrl);
            if (objUrl) {
                $("#img0").attr("src", objUrl).show();
            }
            else {
                $("#img0").hide();
            }
        });

        $(function () {
            $(".file-3").bind('change', function () {
                subUrl = $(this).val();
                $(".yulan").show();
                $(".file-3").val("");
            });

            $(".btn-3").click(function () {
                $("#img-1").attr("src", obUrl);
                $(".yulan").hide();
                $(".file-3").parents(".uploader").find(".filename").val(subUrl);

                var basepath = "";
                var ClassID = $("#ClassID").val();
                var TeacherID = $("#TeacherID").val();
                var image = new Image();
                image.crossOrigin = '';
                image.src = obUrl;
                image.onload = function () {
                    basepath = getBase64Image(image);
                    basepath = basepath.replace(/^data:image/(png|jpg);base64,/, "")
                    //开始异步发送
                    $.ajax("/home/savenewsbackimage", {
                        data: JSON.stringify({ path: basepath, ClassID: ClassID, TeacherID: TeacherID }),
                        type: "POST", dataType: "text", contentType: "application/json;utf-8",
                        success: function (data) {
                            alert(data);
                        }
                    });
                }
            })
            $(".btn-2").click(function () {
                $(".yulan").hide();
            })
        });


        function qd() {
            var objUrl = getObjectURL(this.files[0]);
            obUrl = objUrl;
            console.log("objUrl = " + objUrl);
            if (objUrl) {
                $("#img0").attr("src", objUrl).show();
            }
            else {
                $("#img0").hide();
            }
        }

        function getObjectURL(file) {
            var url = null;
            if (window.createObjectURL != undefined) { // basic
                url = window.createObjectURL(file);
            } else if (window.URL != undefined) { // mozilla(firefox)
                url = window.URL.createObjectURL(file);
            } else if (window.webkitURL != undefined) { // webkit or chrome
                url = window.webkitURL.createObjectURL(file);
            }
            return url;
        }

        //img转码base64
        function getBase64Image(img) {
            var canvas = document.createElement("canvas");
            canvas.width = img.width;
            canvas.height = img.height;

            var ctx = canvas.getContext("2d");
            ctx.drawImage(img, 0, 0, img.width, img.height);
            var ext = img.src.substring(img.src.lastIndexOf(".") + 1).toLowerCase();
            var dataURL = canvas.toDataURL("image/" + ext);
            return dataURL;
        }

    </script>

再看服务器端代码

[HttpPost]
        public ActionResult SaveNewsBackImage(string path, string ClassID, string TeacherID)
        {
            //保存图片到服务器，
            string basePath = "/UploadPic/";

            string imgname = DateTime.Now.Ticks + ".jpg";

            string basepath = HttpContext.Server.MapPath(basePath);

            string Pic_Path = basepath + imgname;

            using (FileStream fs = new FileStream(Pic_Path, FileMode.Create))
            {
                using (BinaryWriter bw = new BinaryWriter(fs))
                {
                    byte[] data = Convert.FromBase64String(path);
                    bw.Write(data);
                    bw.Close();
                }
            }

            //把图片地址存到数据库

            string serpath = ConfigurationManager.AppSettings["Domain"].ToString();
            string classimagePath = serpath + basePath + imgname;

            var flag = new ClassBLL().SaveNewsBackImage(classimagePath, Convert.ToInt32(ClassID), Convert.ToInt32(TeacherID));
            return Content("上传成功");
        }

至此， 大家应该能看明白这个微信内置浏览器的上传方法了~  希望和我一样的朋友， 继续加油，奋斗~ 在路上