一.效果图：
开发框架：MVC，Layui
列表主界面这里就不展示了，可以去看看这篇文章：Layui项目实战，这里讲的是“上传Banner”界面功能：
其中包括，多文件上传，预览，后台接收，保存，仅此而已
二.项目代码：
1.前端Html代码
head头部代码块：
注意：这里引用的是Layui和jQuery插件，不过重点功能还是在jQuery，Layui只是起到样式效果
<head><meta name="viewport" content="width=device-width" /><title>PushCircleBanner</title><link href="~/Scripts/layui/css/layui.css" rel="stylesheet" /><script src="~/Scripts/jquery-3.3.1.js"></script><script src="~/Scripts/layui/layui.js"></script><style>* {margin: 0;padding: 0;}.box {width: 80%;height: 80vh;margin: auto;}.box p {height: 30px;margin: 10px;}#file{display:none;}.ImgsBox img{width:100px;height:100px;}.select,input{width:200px;}</style>
</head>
body代码块：
注意：这里既然是文件上传，重点自然是input[“file”]，multiple=“multiple"多文件上传，accept=”.png,.jpg,.jpeg,.bmp,.gif,.jfif,.ico "限制允许选择的文件类型
<div class="box"><p>性别：</p><p class="layui-input-inline"><select name="sex" class="sex layui-input select"><option value="0" selected>全部</option><option value="1">男</option><option value="2">女</option></select></p><p>是否去重：</p><p class="layui-input-inline"><select name="isDistinct" class="isDistinct layui-input select"><option value="0" selected>否</option><option value="1">是</option></select></p><p>图片上传：</p><p><input type="button" class="layui-btn" name="name" onclick="$('#file').click()" value="上传" /><input id="file" type="file" multiple="multiple" name="img" value="上传" accept=".png,.jpg,.jpeg,.bmp,.gif,.jfif,.ico " onchange="PushFiles()" /></p><p><input type="button" class="layui-btn submit" onclick="Save()" value="保存" /></p><div class="ImgsBox"></div></div>
Js代码块：
注意：PushFiles方法，由点击显示的上传按钮，再触发隐藏的input[“file”]按钮的点击方法，改变files值后触发该方法，实现多文件上传效果，也是这里前端界面展示的重点
<script>var files;function PushFiles() {$('.ImgsBox').html('');files = document.getElementById('file').files;if (files && files.length > 0) {for (var i = 0; i < files.length; i++) {var file = files[i];var URL = window.URL || window.webkitURL;var imgURL = URL.createObjectURL(file);console.log(imgURL);var img = $('<img src="" />');img.attr('src', imgURL);$('.ImgsBox').append(img);}}}
注意：Save方法，由点击保存按钮触发，js的FormData对象进行表单参数收集，ajax再通过文件传输的方式，提交到后台
function Save() {if (files && files.length > 0) {var formData = new FormData();formData.append('sex', $('.sex').val());formData.append('isDistinct', $('.isDistinct').val());for (var i = 0; i < files.length; i++) {formData.append('img_'+i,files[i] );}$.ajax({url: '/Circle/PushBanner',data: formData,type: 'POST',cache: false,//这个参数是jquery特有的，不进行序列化，因为我们不是json格式的字符串，而是要传文件processData: false, //注意这里一定要设置contentType:false，不然会默认为传的是字符串，这样文件就传不过去了contentType: false,//dataType: "json",success: function (res) {if (res.code == 0) {var index = parent.layer.getFrameIndex(window.name);//先得到当前iframe层的索引 parent.layer.close(index);//再执行关闭} else {alert(res.msg);}}})} else {alert("请选择上传文件！");}}</script>
2.后台C#代码
注意：下面的后台代码块，只要把间隔的注意提示去掉，就能拼接出完整的后台代码
/// <summary>/// 图片批量上传/// </summary>/// <returns></returns>public ActionResult PushBanner(){
后台登录校验
if (!(Session["account"] is AccountModel account))return Json(new { code = -1, msg = "登录异常" }, JsonRequestBehavior.AllowGet);
获取前端传输参数：
StringBuilder msg = new StringBuilder();int error = 0;AliyunOssProvider aliyunOss = new AliyunOssProvider();string suffix = string.Empty;var files = Request.Files; //ajax传输文件var sex = Request.Form["sex"] == null ? 0 : int.Parse(Request.Form["sex"]);var isDistinct = Request.Form["isDistinct"] == null ? 0 : int.Parse(Request.Form["isDistinct"]);
多文件循环保存：
for (int i = 0; i < files.Count; i++){var type = files[i].ContentType;if (type.Contains("image")){switch (type){case "image/jpeg":suffix = ".jpg";break;case "image/png":suffix = ".png";break;case "image/bmp":suffix = ".bmp";break;case "image/gif":suffix = ".gif";break;case "image/pipeg":suffix = ".jfif";break;case "image/x-icon":suffix = ".ico";break;default:error++;var obj = new {code = -1,msg = "检测到非指定文件格式（jpg/png/bmp/gif/ico/jfif）"};msg.AppendLine(JsonHelper.SerializeObject(obj));continue;//return Json(new { result = false, messge = "请将图片转化为（jpg/png/bmp/gif/ico/jfif)格式然后上传!" });}if (string.IsNullOrWhiteSpace(suffix)){error++;var obj = new{code = -1,msg = "检测到非指定文件格式（jpg/png/bmp/gif/ico/jfif）"};msg.AppendLine(JsonHelper.SerializeObject(obj));continue;}var file = "banner/";var fileName = DateTime.Now.ToStampDateTime() + "_"+i + suffix;
阿里云图床文件存储，底层不予展示：
try{var absoluteUri = aliyunOss.UploadObject(files[i].InputStream, file + fileName);}catch (Exception e){error++;var obj = new { code = -2, message = "文件上传失败" };msg.AppendLine(JsonHelper.SerializeObject(obj));//return Json(new { result = false, message = "上传失败" });}
Banner信息存数据库：（底层是数据库保存语句）
var res = new CircleBll().AddCircleBanners(new Model.CircleBanner() {ImgUrl = AppConfig.AliyunUrl + file + fileName,Sex = sex.ToString(),IsDistinct = isDistinct.ToString(),OperatorId = account.UserId.ToString()});if (!res){error++;var obj = new { code = -3, message = "圈子Banner数据库存储失败" };}}}return error == 0 ? Json(new { code = 0, msg = "",data = true }): Json(new { code = error * -1,msg = msg.ToString(),data = false });}
