之前查資料有很多虛浮球效果，拖動時後面的背景也跟著移動。後來使用@touchmove.stop.prevent修飾符解決問題。

也根據快取實現了，懸浮球全域性呼叫，位置是前一個頁面移動的位置。

<template>
    <view class="holdon" @touchstart="drag_start" @touchmove.stop.prevent="drag_hmove" @click.capture="toAdUrl">
        <image class="ball"
            :style="'left:'+(moveX == 0 & x>0? x+'%':moveX+'px')+';top:'+(moveY == 0 & y>0? y+'%':moveY+'px')"
            :src
 
="imgUrl" mode="aspectFit">
        </image>
    </view>
</template>
<script>
    export default {
        props: {
            x: {
                type: Number,
                default: 0
            },
            y: {
                type: Number,
                default: 0
            },
            image: {
                type: String,
                
 
default: ''
            }
        },
        data() {
            return {
                start: [0, 0],
                moveY: 200,//起始y座標
                moveX: 10,//起始X座標
                windowWidth: '',
                windowHeight: '',
                imgUrl: ""  //img 地址
            }
        },
        mounted() {
            let location 
 
= uni.getStorageSync('ball-location');
            if (location.x) {
                this.moveX = location.x
            }
            if (location.y) {
                this.moveY = location.y
            }
            const {
                windowWidth,
                windowHeight
            } = uni.getSystemInfoSync();
            this.windowWidth = windowWidth
            this.windowHeight = windowHeight
        },
        methods: {
            toAdUrl() {
            },
            drag_start(event) {
                this.start[0] = event.touches[0].clientX - event.target.offsetLeft;
                this.start[1] = event.touches[0].clientY - event.target.offsetTop;
            },
            drag_hmove(event) {
                let tag = event.touches;
                if (tag[0].clientX < 0) {
                    tag[0].clientX = 0
                }
                if (tag[0].clientY < 0) {
                    tag[0].clientY = 0
                }
                if (tag[0].clientX > this.windowWidth) {
                    tag[0].clientX = this.windowWidth
                }
                if (tag[0].clientY > this.windowHeight) {
                    tag[0].clientY = this.windowHeight
                }
                this.moveX = tag[0].clientX - this.start[0];
                this.moveY = tag[0].clientY - this.start[1];
                let location = {
                    x: this.moveX,
                    y: this.moveY
                };
                //將懸浮球 存快取 其他頁面展示 也在相同位置
                uni.setStorageSync('ball-location', location);
            }
        }
    }
</script>

<style lang="scss" scoped>
    .holdon {
        width: 100%;
        height: 100%;
    }

    .ball {
        width: 120rpx;
        height: 120rpx;
        border-radius: 50%;
        color: #fff;
        font-size: 30upx;
        display: flex;
        justify-content: center;
        align-items: center;
        position: fixed !important;
        z-index: 1000000;
    }
</style>

好了希望能幫助你。