vue子组件中使用window.onresize()只执行一次问题

window.onresize = () => {
                delay(function () {
                    //防抖重画                    
                    _this.handleDispose()
                    _this.handleDraw()
                }, 500)
            }

window.addEventListener('resize', _this.handleReDraw)

 watch: {
        options (newVal, oldVal) {
            let _this = this
            if (newVal) {
                _this.init()
            }
        },
        $route: {
            handler: function (route) {
                const _this = this

                if (route.name != "Index") {
                    //移除监听
                    window.removeEventListener('resize', _this.handleReDraw)
                } else {
                    //监听窗口变化
                    window.addEventListener('resize', _this.handleReDraw)
                }

            },
            immediate: true,
        },
    },

... 
// 页面初始化
    created () { },
    // 页面DOM加载完成
    mounted () {
        let _this = this
        _this.init()

        //监听窗口变化
        window.addEventListener('resize', _this.handleReDraw)

    },
    //离开页面时执行
    destroyed () {
        const _this = this

        //移除监听
        window.removeEventListener('resize', _this.handleReDraw)
    },
...