114 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
			
		
		
	
	
			114 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
| /**
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|  * 使用普通的js方案实现slider
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|  */
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| export default {
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|     watch: {
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|         value(n) {
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|             // 只有在非滑动状态时,才可以通过value更新滑块值,这里监听,是为了让用户触发
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|             if (this.status === 'end') {
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|                 this.updateSliderPlacement(n, true)
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|             }
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|         }
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|     },
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|     mounted() {
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|         this.init()
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|     },
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|     methods: {
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|         init() {
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|             this.getSliderRect()
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|         },
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|         // 获取slider尺寸
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|         getSliderRect() {
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|             // 获取滑块条的尺寸信息
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|             setTimeout(() => {
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|                 this.$uGetRect('.u-slider').then((rect) => {
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|                     this.sliderRect = rect
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|                     this.updateSliderPlacement(this.value, true)
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|                 })
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|             }, 10)
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|         },
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|         // 是否可以操作
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|         canNotDo() {
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|             return this.disabled
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|         },
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|         // 获取当前手势点的X轴位移值
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|         getTouchX(e) {
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|             return e.touches[0].clientX
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|         },
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|         formatStep(value) {
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|             // 移动点占总长度的百分比
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|             return Math.round(Math.max(this.min, Math.min(value, this.max)) / this.step) * this.step
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|         },
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|         // 发出事件
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|         emitEvent(event, value) {
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|             this.$emit(event, value || this.value)
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|         },
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|         // 标记当前手势的状态
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|         setTouchStatus(status) {
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|             this.status = status
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|         },
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|         onTouchStart(e) {
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|             if (this.canNotDo()) {
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|                 return
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|             }
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|             // 标示当前的状态为开始触摸滑动
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|             this.emitEvent('start')
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|             this.setTouchStatus('start')
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|         },
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|         onTouchMove(e) {
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|             if (this.canNotDo()) {
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|                 return
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|             }
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|             // 滑块的左边不一定跟屏幕左边接壤,所以需要减去最外层父元素的左边值
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|             const x = this.getTouchX(e)
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|             const { left, width } = this.sliderRect
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|             const distanceX = x - left
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|             // 获得移动距离对整个滑块的百分比值,此为带有多位小数的值,不能用此更新视图
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|             // 否则造成通信阻塞,需要每改变一个step值时修改一次视图
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|             const percent = (distanceX / width) * 100
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|             this.setTouchStatus('moving')
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|             this.updateSliderPlacement(percent, true, 'moving')
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|         },
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|         onTouchEnd() {
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|             if (this.canNotDo()) {
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|                 return
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|             }
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|             this.emitEvent('end')
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|             this.setTouchStatus('end')
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|         },
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|         // 设置滑点的位置
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|         updateSliderPlacement(value, drag, event) {
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|             // 去掉小数部分,同时也是对step步进的处理
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|             const { width } = this.sliderRect
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|             const percent = this.formatStep(value)
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|             // 设置移动的值
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|             const barStyle = {
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|                 width: `${percent / 100 * width}px`
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|             }
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|             // 移动期间无需过渡动画
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|             if (drag === true) {
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|                 barStyle.transition = 'none'
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|             } else {
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|                 // 非移动期间,删掉对过渡为空的声明,让css中的声明起效
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|                 delete barStyle.transition
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|             }
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|             // 修改value值
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|             this.$emit('input', percent)
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|             // 事件的名称
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|             if (event) {
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|                 this.emitEvent(event, percent)
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|             }
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|             this.barStyle = barStyle
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|         },
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|         onClick(e) {
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|             if (this.canNotDo()) {
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|                 return
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|             }
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|             // 直接点击滑块的情况,计算方式与onTouchMove方法相同
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|             const { left, width } = this.sliderRect
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|             const value = ((e.detail.x - left) / width) * 100
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|             this.updateSliderPlacement(value, false, 'click')
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|         }
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|     }
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| }
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