el-dialog 模態框拖拽

1.拖拽效果
1.1 拖拽前

1.2 拖拽後

2.拖拽組件。
把代碼單獨拷貝在一個js裏便可，這裏寫在公共文件夾common/js/directives.js裏,具體看步驟3示例。
參考API https://cn.vuejs.org/v2/api/ 的Vue.directive。

import Vue from 'vue';

// v-dialogDrag: 彈窗拖拽屬性 （重點！！！ 給模態框添加這個屬性模態框就能拖拽了）
Vue.directive('dialogDrag', { //屬性名稱dialogDrag，前面加v- 使用
  bind(el, binding, vnode, oldVnode) {
    const dialogHeaderEl = el.querySelector('.el-dialog__header');
    const dragDom = el.querySelector('.el-dialog');
    //dialogHeaderEl.style.cursor = 'move';
    dialogHeaderEl.style.cssText += ';cursor:move;'
    dragDom.style.cssText += ';top:0px;'

    // 獲取原有屬性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
    const sty = (function() {
      if (window.document.currentStyle) {
        return (dom, attr) => dom.currentStyle[attr];
      } else{
        return (dom, attr) => getComputedStyle(dom, false)[attr];
      }
    })()

    dialogHeaderEl.onmousedown = (e) => {
      // 鼠標按下，計算當前元素距離可視區的距離
      const disX = e.clientX - dialogHeaderEl.offsetLeft;
      const disY = e.clientY - dialogHeaderEl.offsetTop;

      const screenWidth = document.body.clientWidth; // body當前寬度
      const screenHeight = document.documentElement.clientHeight; // 可見區域高度(應爲body高度，可某些環境下沒法獲取)

      const dragDomWidth = dragDom.offsetWidth; // 對話框寬度
      const dragDomheight = dragDom.offsetHeight; // 對話框高度

      const minDragDomLeft = dragDom.offsetLeft;
      const maxDragDomLeft = screenWidth - dragDom.offsetLeft - dragDomWidth;

      const minDragDomTop = dragDom.offsetTop;
      const maxDragDomTop = screenHeight - dragDom.offsetTop - dragDomheight;


      // 獲取到的值帶px 正則匹配替換
      let styL = sty(dragDom, 'left');
      let styT = sty(dragDom, 'top');

      // 注意在ie中 第一次獲取到的值爲組件自帶50% 移動以後賦值爲px
      if(styL.includes('%')) {
        styL = +document.body.clientWidth * (+styL.replace(/\%/g, '') / 100);
        styT = +document.body.clientHeight * (+styT.replace(/\%/g, '') / 100);
      }else {
        styL = +styL.replace(/\px/g, '');
        styT = +styT.replace(/\px/g, '');
      };

      document.onmousemove = function (e) {
        // 經過事件委託，計算移動的距離
        let left = e.clientX - disX;
        let top = e.clientY - disY;

        // 邊界處理
        if (-(left) > minDragDomLeft) {
          left = -(minDragDomLeft);
        } else if (left > maxDragDomLeft) {
          left = maxDragDomLeft;
        }

        if (-(top) > minDragDomTop) {
          top = -(minDragDomTop);
        } else if (top > maxDragDomTop) {
          top = maxDragDomTop;
        }

        // 移動當前元素
        dragDom.style.cssText += `;left:${left + styL}px;top:${top + styT}px;`;
      };

      document.onmouseup = function (e) {
        document.onmousemove = null;
        document.onmouseup = null;
      };
    }
  }
})

3.拖拽組件的引入，只要引入了directives.js便可

3.1引入

import '../common/js/directives.js'

3.2示例

4.使用。
給el-dialog添加屬性v-dialogDrag便可

代碼：

<el-dialog
  title="外幣維護"
  v-dialogDrag
  size='mini'
  :close-on-click-modal="false"
  :visible.sync="dialogVisible"
  width="400px"
  @close="close">
   <div  class="mini-font mb-5 balance">
        <el-form :model="form">
            <el-form-item label="外幣金額" :label-width="formLabelWidth">
                <!-- <el-input v-model="form.fmMoney" :value="form.fmMoney | formatMoney1" auto-complete="off"  size='mini'></el-input> -->
                <el-input-number 
                    size='small'
                    :precision="2"
                    :controls="false"  
                    v-model="form.fmMoney"
                    auto-complete="off">
                </el-input-number>
            </el-form-item>
            <el-form-item label="匯率" :label-width="formLabelWidth">
                <!-- <el-input v-model="form.percent" auto-complete="off"  size='mini'></el-input> -->
                <el-input-number 
                    size='small'
                    :precision="4"
                    :controls="false"  
                    v-model="form.percent"
                    auto-complete="off">
                </el-input-number>
            </el-form-item>
            <el-form-item label="本位幣金額" :label-width="formLabelWidth">
                <!-- <el-input v-model="form.balance" auto-complete="off"  size='mini'></el-input> -->
                <el-input-number 
                    size='small'
                    :precision="2"
                    :controls="false"  
                    v-model="form.balance"
                    auto-complete="off">
                </el-input-number>
            </el-form-item>
        </el-form>
  </div>
  <span slot="footer" class="dialog-footer">
    <el-button type="primary" size='mini' @click="sureBtn">肯定</el-button>
    <el-button type="primary" size='mini' @click="close">取消</el-button>
  </span>
</el-dialog>

參考：https://www.jianshu.com/p/c3c...