Vue使用directive指令实现Element中Dialog等弹框组件的移动与缩放

Posted 2021-08-30 北溟溟

前言

在使用ElementUI的Dialog等弹框组件中，我们一定有这样的困扰，我们的弹框无法移动，导致下面遮罩的内容不能看到，或者我们的弹框的内容显示不完整，都会影响组件的使用体验。本小节我们通过vue的directive自定义指令实现弹框的移动和缩放的功能。关于directive自定义指令的相关内容请自行参考官方文档学习。源码地址：https://gitee.com/northcangap/atp.git。话不多说，上效果。

正文

• 创建dialogDrag指令derective.js
  

import Vue from 'vue'

Vue.directive('dialogDrag', {
    bind: function (el) {
        //弹框可拉伸最小宽高
        let minWidth = 400;
        let minHeight = 300;
        //初始非全屏
        let isFullScreen = false;
        //当前宽高
        let nowWidth = 0;
        let nowHight = 0;
        //当前顶部高度
        let nowMarginTop = 0;
        //获取弹框头部（这部分可双击全屏）
        const dialogHeaderEl = el.querySelector('.el-dialog__header');
        //弹窗
        const dragDom = el.querySelector('.el-dialog');
        //给弹窗加上overflow auto；不然缩小时框内的标签可能超出dialog；
        dragDom.style.overflow = "auto";
        //头部加上可拖动cursor
        dialogHeaderEl.style.cursor = 'move';
        // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
        const sty = dragDom.currentStyle || window.getComputedStyle(dragDom, null);
        let moveDown = (e) => {
            // 鼠标按下，计算当前元素距离可视区的距离
            const disX = e.clientX - dialogHeaderEl.offsetLeft;
            const disY = e.clientY - dialogHeaderEl.offsetTop;
            // 获取到的值带px 正则匹配替换
            let styL, styT;
            // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
            if (sty.left.includes('%')) {
                styL = +document.body.clientWidth * (+sty.left.replace(/\\\\%/g, '') / 100);
                styT = +document.body.clientHeight * (+sty.top.replace(/\\\\%/g, '') / 100);
            } else {
                styL = +sty.left.replace('px', '');
                styT = +sty.top.replace('px', '');
            }
            document.onmousemove = function (e) {
                // 通过事件委托，计算移动的距离
                const l = e.clientX - disX;
                const t = e.clientY - disY;
                // 移动当前元素
                dragDom.style.left = `${l + styL}px`;
                dragDom.style.top = `${t + styT}px`;
            };
            document.onmouseup = function (e) {
                document.onmousemove = null;
                document.onmouseup = null;
            };
        };
        dialogHeaderEl.onmousedown = moveDown;
        //双击头部全屏效果
        dialogHeaderEl.ondblclick = (e) => {
            if (!isFullScreen) {
                nowHight = dragDom.clientHeight;
                nowWidth = dragDom.clientWidth;
                nowMarginTop = dragDom.style.marginTop;
                dragDom.style.left = 0;
                dragDom.style.top = 0;
                dragDom.style.height = "100VH";
                dragDom.style.width = "100VW";
                dragDom.style.marginTop = 0;
                isFullScreen = true;
                dialogHeaderEl.style.cursor = 'initial';
                dialogHeaderEl.onmousedown = null;
            } else {
                dragDom.style.height = "auto";
                dragDom.style.width = nowWidth + 'px';
                dragDom.style.marginTop = nowMarginTop;
                dragDom.style.overflow = 'hidden';
                isFullScreen = false;
                dialogHeaderEl.style.cursor = 'move';
                dialogHeaderEl.onmousedown = moveDown;
            }
        };
        dragDom.onmousemove = function (e) {
            if (e.clientX > dragDom.offsetLeft + dragDom.clientWidth - 10 || dragDom.offsetLeft + 10 > e.clientX) {
                dragDom.style.cursor = 'w-resize';
            } else if (el.scrollTop + e.clientY > dragDom.offsetTop + dragDom.clientHeight - 10) {
                dragDom.style.cursor = 's-resize';
            } else {
                dragDom.style.cursor = 'default';
                dragDom.onmousedown = null;
            }
            dragDom.onmousedown = (e) => {
                const clientX = e.clientX;
                const clientY = e.clientY;
                let elW = dragDom.clientWidth;
                let elH = dragDom.clientHeight;
                let EloffsetLeft = dragDom.offsetLeft;
                let EloffsetTop = dragDom.offsetTop;
                dragDom.style.userSelect = 'none';
                let ELscrollTop = el.scrollTop;
                //判断点击的位置是不是为头部
                if (clientX > EloffsetLeft && clientX < EloffsetLeft + elW && clientY > EloffsetTop && clientY < EloffsetTop + 100) {
                    //如果是头部在此就不做任何动作，以上有绑定dialogHeaderEl.onmousedown = moveDown;
                    return;
                } else {
                    document.onmousemove = function (e) {
                        //左侧鼠标拖拽位置
                        if (clientX > EloffsetLeft && clientX < EloffsetLeft + 10) {
                            //往左拖拽
                            if (clientX > e.clientX) {
                                dragDom.style.width = elW + (clientX - e.clientX) * 2 + 'px';
                            }
                            //往右拖拽
                            if (clientX < e.clientX) {
                                if (dragDom.clientWidth >= minWidth) {
                                    dragDom.style.width = elW - (e.clientX - clientX) * 2 + 'px';
                                }
                            }
                        }
                        //右侧鼠标拖拽位置
                        if (clientX > EloffsetLeft + elW - 10 && clientX < EloffsetLeft + elW) {
                            //往左拖拽
                            if (clientX > e.clientX) {
                                if (dragDom.clientWidth >= minWidth) {
                                    dragDom.style.width = elW - (clientX - e.clientX) * 2 + 'px';
                                }
                            }
                            //往右拖拽
                            if (clientX < e.clientX) {
                                dragDom.style.width = elW + (e.clientX - clientX) * 2 + 'px';
                            }
                        }
                        //底部鼠标拖拽位置
                        if (ELscrollTop + clientY > EloffsetTop + elH - 20 && ELscrollTop + clientY < EloffsetTop + elH) {
                            //往上拖拽
                            if (clientY > e.clientY) {
                                if (dragDom.clientHeight >= minHeight) {
                                    dragDom.style.height = elH - (clientY - e.clientY) * 2 + 'px';
                                }
                            }
                            //往下拖拽
                            if (clientY < e.clientY) {
                                dragDom.style.height = elH + (e.clientY - clientY) * 2 + 'px';
                            }
                        }
                    };
                    //拉伸结束
                    document.onmouseup = function (e) {
                        document.onmousemove = null;
                        document.onmouseup = null;
                    };
                }
            }
        }
    }
});

•  在main.js中引入指令

• DialogTemplate.vue示例中使用指令

<template>
  <div class="container">
    <div class="title">
      <span>弹框拖拽及双击全屏示例</span>
      <el-divider direction="vertical"></el-divider>
      <router-link to="home">
        <span style="font-size: 18px;">退出</span>
      </router-link>
    </div>
    <div>
      <el-button type="text" @click="centerDialogVisible = true">点击打开Dialog弹框</el-button>
      <el-dialog
          title="提示"
          v-dialog-drag
          :visible.sync="centerDialogVisible"
          width="40%">
        <span>这是一个可以移动、放大、缩小的弹框！</span>
        <span slot="footer" class="dialog-footer">
          <el-button @click="centerDialogVisible = false">取 消</el-button>
          <el-button type="primary" @click="centerDialogVisible = false">确 定</el-button>
        </span>
      </el-dialog>
    </div>
  </div>
</template>

<script>
export default {
  name: "DialogTemplate",
  data() {
    return {
      centerDialogVisible: false
    };
  }
}
</script>

<style scoped lang="scss">
.container {
  padding: 10px;

  .page {
    float: right;
    margin-top: 20px;
  }

  a {
    text-decoration: none;
  }

  .title {
    font-size: 20px;
    font-weight: bold;
  }

  ::v-deep .el-dialog {
    margin-bottom: 0;
  }
}
</style>

 

•  验证

 

结语

ok,关于element中dialog等相关弹框组件的移动与缩放案例就到这里了，喜欢的小伙伴收藏、关注加点赞哦，你的支持就是作者最大的创作动力。我们下期见。。。