layui实现多图片上传并限制上传的图片数量

    //给图片添加删除
    function mouseChange() {
        $(document).on("mouseenter mouseleave", ".file-iteme", function (event) {
          if (event.type === "mouseenter") {
            //鼠标悬浮
            $(this).children(".info").fadeIn("fast");
            $(this).children(".handle").fadeIn("fast");
          } else if (event.type === "mouseleave") {
            //鼠标离开
            $(this).children(".info").hide();
            $(this).children(".handle").hide();
          }
        });
 
    }
    mouseChange();
 
  //json的length 
  function getJsonLength(jsonData){
      var jsonLength = 0;
      for(var item in jsonData){
        jsonLength++;
      }
      return jsonLength;
    }
 
    //多图片上传
    var ImgList = $('#uploader-list'),uploadListIns =upload.render({
      elem: '#chooseImg',
      url: $("#projectUrl").val()+ '/img/imgUpload.do',
      accept: 'images',
      acceptMime: 'image/jpg,image/png,image/jpeg',
      exts: 'jpg|png|jpeg',
      size: 1024,
      multiple: true,
      auto: true,
      choose: function(obj){
        var files = obj.pushFile(); //将每次选择的文件追加到文件队列
        var len = getJsonLength(files);
        //读取本地文件
        obj.preview(function (index, file, result) {
          if (parseInt(len)+parseInt(coachPicsArray.length)-count > 6){
            layer.msg("门店图片不能超过6张");
            //遍历
            $.each(files,function(_key){
              var key = _key;
              var value = files[_key];
              if(_key == index)
              { //删除
                delete files[_key];
              }
            });
          }else {
            var reader = new FileReader();
            reader.onload = function (e) {
              var image = new Image();
              image.onload = function () {
                var realWidth = image.width;
                var realHeight = image.height;
                var tr = $(['<div id="upload-' + index + '" class="file-iteme">' +
                '<div class="removeIcon handle"> <i class="layui-icon" style="color: white ;margin-right: 40%">&#xe640;</i></div>' +
                '<img style="color: white;width: 120px" "showBig(this)" src=' + result + ' id="img-' + index + '">' +
                '</div>'].join(''));
 
                //删除
                tr.find('.handle').on('click', function () {
                  $(this).parent().remove();
                  delete files[index]; //删除对应的文件
                  var value = $("#clubCoachPics").val().split(",");
                  var arr = [];
                  for( var i in value){
                    if (value[i] != $(this).next().data('value')){
                      arr.push(value[i]);
                    }
                  }
                  $("#clubCoachPics").val(arr.join(",")) ;
 
                });
                ImgList.append(tr);
 
              };
              image.src = result;
            };
            //正式读取文件
            reader.readAsDataURL(file);
          }
        });
      },
      before: function (obj) {
        layer.msg('图片上传中...', {
          icon: 16,
          shade: 0.01,
          time: 3000
        })
      },
      done: function (res, index, upload) {
        $("#img-"+ index + "").attr("data-value",res.imgUrl);
        if(res.code == 0){ //上传成功
          var imgUrl = $("#clubCoachPics").val();
          if(imgUrl==null||imgUrl==""){
            $("#clubCoachPics").val(res.imgUrl);
          }else{
            $("#clubCoachPics").val(imgUrl+","+res.imgUrl);
          }
          delete files[index]; //删除文件队列已经上传成功的文件
          return;
        };
 
      }
    });