vue-resource在vuecli3中请求headers修改

this.$resource.delete({
                    user_code: Cookie.get("empid"),
                    date: date,
                    file_name: file_name
                },{
                    headers:{
                        'Content-type': 'application/x-www-form-urlencoded'
                    }
                }).then(function(e){
                    //this.data4 = e.body.file_name_list;
                    this.$Message.success(e.body.msg);
                    this.$Spin.hide();
                    this.search();
                });