ajax.POST请求偶尔被浏览器截停，后台接收不到请求，Status返回（canceled）的原因。

                methods: {
                    updateTimer: function() {
                        $.ajax({
                            type: "POST",
                            url: "http://127.0.0.1:8080/api/v1/timer/update",
                            contentType: "application/json",
                            data: JSON.stringify(this.timer),
                            // async: false , //改为同步
                            success: function(response) {
                                console.log(response);
                                if (response.resultCode == ‘20000‘) {
                                    layer.msg("更新成功!");
                                    window.parent.location.reload(); //刷新父页面
                                    var index = parent.layer.getFrameIndex(window.name); //获取窗口索引
                                    parent.layer.close(index); // 关闭layer
                                } else {
                                    // 失败了
                                    layer.msg(‘添加失败!‘)
                                }
                            },
                            error: function(jqXHR, textStatus, errorThrown) {
                                alert("error!");
                                console.log(jqXHR);
                                console.log(textStatus);
                                console.log(errorThrown);
                            }
                        });
                    }
                }