演示图如下：
代码如下
JS部分
Vue.component('dragIcon', {
template: `
<transition>
<div ref="dragIcon"
class="dragIcon"
@touchstart="handleTouchStart"
@touchmove.prevent="handleTouchMove"
@touchend="handleTouchEnd"
:style="{left: left + 'px',top: top + 'px',width: itemWidth + 'px',height: itemHeight + 'px'}"
v-text="text"
v-if="isShow"
>
</div>
</transition>
`,
props: {
text: {
type: String,
default: '首页'
},
itemWidth: {
type: Number,
default: 40
},
itemHeight: {
type: Number,
default: 40
}
},
data() {
return {
left: 0,
top: 0,
startToMove: false,
isShow: true,
timer: null,
currentTop: null,
clientW: document.documentElement.clientWidth,
clientH: document.documentElement.clientHeight
}
},
created () {
this.left = (this.clientW - this.itemWidth)
this.top = (this.clientH/2 - this.itemHeight/2)
},
mounted() {
this.bindScrollEvent()
},
beforeDestroy() {
this.removeScrollEvent()
},
methods: {
handleTouchStart() {
this.startToMove = true
this.$refs.dragIcon.style.transition = "none"
},
handleTouchMove(e) {
const clientX = e.targetTouches[0].clientX
const clientY = e.targetTouches[0].clientY
const isInScreen = clientX <= this.clientW && clientX >= 0 && clientY <= this.clientH && clientY >=0
if(this.startToMove && e.targetTouches.length === 1) {
if(isInScreen) {
this.left = clientX - this.itemWidth/2
this.top = clientY - this.itemHeight/2
}
}
},
handleTouchEnd() {
if(this.left < (this.clientW / 2)) {
this.left = 0
this.handleIconY()
} else {
this.left = this.clientW - this.itemWidth
this.handleIconY()
}
this.$refs.dragIcon.style.transition = "all .3s"
},
handleIconY() {
if (this.top < 0) {
this.top = 0
} else if(this.top + this.itemHeight > this.clientH) {
this.top = this.clientH - this.itemHeight
}
},
bindScrollEvent() {
window.addEventListener('scroll', this.handleScrollStart)
},
removeScrollEvent() {
window.removeEventListener('scroll',this.handleScrollStart)
},
handleScrollStart() {
this.isShow = false
this.timer && clearTimeout(this.timer)
this.timer = setTimeout(() => {
this.handleScrollEnd()
},300)
this.currentTop = document.documentElement.scrollTop || document.body.scrollTop
},
handleScrollEnd() {
this.scrollTop = document.documentElement.scrollTop || document.body.scrollTop
if(this.scrollTop == this.currentTop) {
this.isShow = true
}
}
}
})
HTML部分
<div id="app">
<div class="content1">1111</div>
<div class="content2">2222</div>
<drag-icon></drag-icon>
</div>
style部分
.dragIcon {
position: fixed;
width: 40px;
height: 40px;
border-radius: 50%;
background-color: gray;
line-height: 40px;
text-align: center;
color: #fff;
}
.content1 {
height: 400px;
background-color: rgb(230,180,80);
}
.content2 {
height: 500px;
background-color: rgb(227,230,195);
}
.v-enter {
opacity: 1;
}
.v-leave-to {
opacity: 0;
}
.v-enter-active,
.v-leave-active {
transition: opacity 0.3s;
}