前言
在做后端管理系统中,像弹窗或大的表单时,经常会有滚动条的出现,但有些时候如流程、图片等操作时,仅仅使用鼠标拖动滚动条操作不太方便,如果使用鼠标拖拽图片或容器来触发滚动条的移动就比较方便了
功能设计
如果要实现鼠标辅助触发滚动条的移动,需要借助 mousedown,mouseup,mousemove 三个事件,通过鼠标的移动来动态修改滚动条的scrollLeft和scrollTop,来模拟实现滚动条的位置变更。
考虑到鼠标的拖动有独立和可复用性,可以创建一个类来封装鼠标事件,使用时只要把事件挂到指定的容器上,就可以实现功能的复用
1、创建鼠标移动事件类
创建move.js
// 鼠标移动滚动位置类
class Drag {constructor(vm) {this.dragWrap = vm;// 要挂载的容器this._dom = {};this._x = 0;this._y = 0;this._top = 0;this._left = 0;this.move = false;this.down = false;this.init.apply(this, arguments);}// 绑定事件init() {this.bindEvent();}// 给要素增加鼠标事件// mousedown 按下初始化// mousemove 移动// mouseup,mouseleave 松开,移出结束移动bindEvent() {let t = this;this.dragWrap.addEventListener('mousedown', (e) => {e && e.preventDefault();if (!t.move) {t.move = false;t.down = true;t._x = e.clientX;t._y = e.clientY;t._top = t.dragWrap.scrollTop;t._left = t.dragWrap.scrollLeft;}});this.dragWrap.addEventListener('mouseup', (e) => {e && e.preventDefault();t.move = false;t.down = false;});this.dragWrap.addEventListener('mouseleave', (e) => {e && e.preventDefault();t.move = false;t.down = false;});this.dragWrap.addEventListener('mousemove', (e) => {if (t.down) {e && e.preventDefault();t.move = true;let x = t._x - e.clientX;let y = t._y - e.clientY;t.dragWrap.scrollLeft = t._left + x;t.dragWrap.scrollTop = t._top + y;}});}
}
export default Drag;
在页面中使用
1.在页面中使用move.js类,实现鼠标移动触发滚动条位置的移动
2.给svg添加放大功能
<template><el-row class="app-container"><el-col><el-form ref="form" v-model="value" label-width="80px" size="mini" style="position: absolute;top: 32px;z-index: 999;"><el-form-item label="缩放" prop="value"><el-input-number v-model="value" @change="changeSlider" :min="0" :max="3"></el-input-number></el-form-item></el-form><div id="navShow" style="text-align: center;overflow: hidden;height:90vh;border: 1px solid #000000;"><div><svg id="svgShow" style="cursor:pointer;width:96%;height:96%;padding: 10px;"></svg></div></div></el-col></el-row>
</template><script>
import Drag from '@/utils/move.js';
export default {name: 'ProcessingFlow',data() {return {value: 2,}},mounted() {this.changeSlider()this.initScroll()},methods: {changeSlider() {let svg = document.getElementById('svgShow')if (this.value === 1) {svg.style.transform = 'scale(1.6)'} else if (this.value === 2) {svg.style.transform = 'scale(1.9)'} else if (this.value === 3) {svg.style.transform = 'scale(2.2)'} else {svg.style.transform = 'scale(1)'}svg.style.transformOrigin = ' 0 0'let nav = document.getElementById('navShow')// 滚动元素的父容器:刷新滚轮nav.scrollIntoView()},initScroll() {let nav = document.getElementById('navShow')new Drag(nav)},}
}
</script><style scoped>
</style>
实现效果