项目使用vue+element UI  根据文本内容长度 进行悬浮提示 （内容过长截取内容显示... 并在鼠标悬浮的时候显示全部），如果内容没有超长就不需要进行截取显示
 

代码内容:

<template>
  <div :style="{'width':width,'height':height}" ref="nariTootip" class="nariTootip">
    <div class=" pointer " @mouseenter="handleCellMouseEnter($event)" @mouseleave="handleCellMouseLeave($event)">
      <div class="topicStyle totip"> {{ value }} </div>
    </div>
    <el-tooltip ref="tooltip" effect="dark" :content="tooltipContent" :placement="placement"> </el-tooltip>
  </div>
</template>
<script>
import debounce from 'throttle-debounce/debounce'
import { getStyle, hasClass } from '@/utils/dom.js'

export default {
  name: "nariTootip",
  props: {
    value: {
      type: String,
      default: "",
    },
    width: {
      type: String,
      default: "100%",
    },
    height: {
      type: String,
      default: "100%",
    },
    placement: {
      type: String,
      default: "top",
    },
  },
  data() {
    return {
      tooltipContent: ''
    }
  },
  created() {
    this.activateTooltip = debounce(50, tooltip => tooltip.handleShowPopper())
  },
  methods: {

    // 鼠标移入
    handleCellMouseEnter(event) {
      const target = event.target
      // 判断是否text-overflow, 如果是就显示tooltip
      let child = target.querySelector('.topicStyle')
      // 如果区域宽度被限定，则通过高度判断
      let heightFlag = child.scrollHeight > child.offsetHeight

      // use range width instead of scrollWidth to determine whether the text is overflowing
      // to address a potential FireFox bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1074543#c3
      const range = document.createRange()
      range.setStart(child, 0)
      range.setEnd(child, child.childNodes.length)
      const rangeWidth = range.getBoundingClientRect().width // 文本区域宽度
      const padding = (parseInt(getStyle(target, 'paddingLeft'), 10) || 0) +
        (parseInt(getStyle(target, 'paddingRight'), 10) || 0)
      if ((rangeWidth + padding > target.offsetWidth || child.scrollWidth > child.offsetWidth) || heightFlag && this.$refs.tooltip) {
        const tooltip = this.$refs.tooltip
        // TODO 会引起整个 Table 的重新渲染，需要优化
        this.tooltipContent = target.innerText || target.textContent
        tooltip.referenceElm = target
        tooltip.$refs.popper && (tooltip.$refs.popper.style.display = 'none')
        tooltip.doDestroy()
        tooltip.setExpectedState(true)
        this.activateTooltip(tooltip)
      }
    },

    // 鼠标移出  
    handleCellMouseLeave(event) {
      const tooltip = this.$refs.tooltip
      if (tooltip) {
        tooltip.setExpectedState(false)
        tooltip.handleClosePopper()
      }
    },



  },
};
</script>
<style lang="scss" scoped>
.nariTootip {
  .totip {
    display: inline-block;
    white-space: nowrap;
    text-overflow: ellipsis;
    overflow: hidden;
    width: 100%;
    font-size: 12px;
  }
}
</style>

 

2  参考elementUI table 表格 自适应悬浮提示效果（）

因引用如下

 

 

这个是dom.js 代码

/* istanbul ignore next */

import Vue from 'vue';

const isServer = Vue.prototype.$isServer;
const SPECIAL_CHARS_REGEXP = /([\:\-\_]+(.))/g;
const MOZ_HACK_REGEXP = /^moz([A-Z])/;
const ieVersion = isServer ? 0 : Number(document.documentMode);

/* istanbul ignore next */
const trim = function(string) {
  return (string || '').replace(/^[\s\uFEFF]+|[\s\uFEFF]+$/g, '');
};
/* istanbul ignore next */
const camelCase = function(name) {
  return name.replace(SPECIAL_CHARS_REGEXP, function(_, separator, letter, offset) {
    return offset ? letter.toUpperCase() : letter;
  }).replace(MOZ_HACK_REGEXP, 'Moz$1');
};

/* istanbul ignore next */
export const on = (function() {
  if (!isServer && document.addEventListener) {
    return function(element, event, handler) {
      if (element && event && handler) {
        element.addEventListener(event, handler, false);
      }
    };
  } else {
    return function(element, event, handler) {
      if (element && event && handler) {
        element.attachEvent('on' + event, handler);
      }
    };
  }
})();

/* istanbul ignore next */
export const off = (function() {
  if (!isServer && document.removeEventListener) {
    return function(element, event, handler) {
      if (element && event) {
        element.removeEventListener(event, handler, false);
      }
    };
  } else {
    return function(element, event, handler) {
      if (element && event) {
        element.detachEvent('on' + event, handler);
      }
    };
  }
})();

/* istanbul ignore next */
export const once = function(el, event, fn) {
  var listener = function() {
    if (fn) {
      fn.apply(this, arguments);
    }
    off(el, event, listener);
  };
  on(el, event, listener);
};

/* istanbul ignore next */
export function hasClass(el, cls) {
  if (!el || !cls) return false;
  if (cls.indexOf(' ') !== -1) throw new Error('className should not contain space.');
  if (el.classList) {
    return el.classList.contains(cls);
  } else {
    return (' ' + el.className + ' ').indexOf(' ' + cls + ' ') > -1;
  }
};

/* istanbul ignore next */
export function addClass(el, cls) {
  if (!el) return;
  var curClass = el.className;
  var classes = (cls || '').split(' ');

  for (var i = 0, j = classes.length; i < j; i++) {
    var clsName = classes[i];
    if (!clsName) continue;

    if (el.classList) {
      el.classList.add(clsName);
    } else if (!hasClass(el, clsName)) {
      curClass += ' ' + clsName;
    }
  }
  if (!el.classList) {
    el.className = curClass;
  }
};

/* istanbul ignore next */
export function removeClass(el, cls) {
  if (!el || !cls) return;
  var classes = cls.split(' ');
  var curClass = ' ' + el.className + ' ';

  for (var i = 0, j = classes.length; i < j; i++) {
    var clsName = classes[i];
    if (!clsName) continue;

    if (el.classList) {
      el.classList.remove(clsName);
    } else if (hasClass(el, clsName)) {
      curClass = curClass.replace(' ' + clsName + ' ', ' ');
    }
  }
  if (!el.classList) {
    el.className = trim(curClass);
  }
};

/* istanbul ignore next */
export const getStyle = ieVersion < 9 ? function(element, styleName) {
  if (isServer) return;
  if (!element || !styleName) return null;
  styleName = camelCase(styleName);
  if (styleName === 'float') {
    styleName = 'styleFloat';
  }
  try {
    switch (styleName) {
      case 'opacity':
        try {
          return element.filters.item('alpha').opacity / 100;
        } catch (e) {
          return 1.0;
        }
      default:
        return (element.style[styleName] || element.currentStyle ? element.currentStyle[styleName] : null);
    }
  } catch (e) {
    return element.style[styleName];
  }
} : function(element, styleName) {
  if (isServer) return;
  if (!element || !styleName) return null;
  styleName = camelCase(styleName);
  if (styleName === 'float') {
    styleName = 'cssFloat';
  }
  try {
    var computed = document.defaultView.getComputedStyle(element, '');
    return element.style[styleName] || computed ? computed[styleName] : null;
  } catch (e) {
    return element.style[styleName];
  }
};

/* istanbul ignore next */
export function setStyle(element, styleName, value) {
  if (!element || !styleName) return;

  if (typeof styleName === 'object') {
    for (var prop in styleName) {
      if (styleName.hasOwnProperty(prop)) {
        setStyle(element, prop, styleName[prop]);
      }
    }
  } else {
    styleName = camelCase(styleName);
    if (styleName === 'opacity' && ieVersion < 9) {
      element.style.filter = isNaN(value) ? '' : 'alpha(opacity=' + value * 100 + ')';
    } else {
      element.style[styleName] = value;
    }
  }
};

export const isScroll = (el, vertical) => {
  if (isServer) return;

  const determinedDirection = vertical !== null || vertical !== undefined;
  const overflow = determinedDirection
    ? vertical
      ? getStyle(el, 'overflow-y')
      : getStyle(el, 'overflow-x')
    : getStyle(el, 'overflow');

  return overflow.match(/(scroll|auto)/);
};

export const getScrollContainer = (el, vertical) => {
  if (isServer) return;

  let parent = el;
  while (parent) {
    if ([window, document, document.documentElement].includes(parent)) {
      return window;
    }
    if (isScroll(parent, vertical)) {
      return parent;
    }
    parent = parent.parentNode;
  }

  return parent;
};

export const isInContainer = (el, container) => {
  if (isServer || !el || !container) return false;

  const elRect = el.getBoundingClientRect();
  let containerRect;

  if ([window, document, document.documentElement, null, undefined].includes(container)) {
    containerRect = {
      top: 0,
      right: window.innerWidth,
      bottom: window.innerHeight,
      left: 0
    };
  } else {
    containerRect = container.getBoundingClientRect();
  }

  return elRect.top < containerRect.bottom &&
    elRect.bottom > containerRect.top &&
    elRect.right > containerRect.left &&
    elRect.left < containerRect.right;
};

效果图是：

内容没有过长的时候

内容过长的时候

 

 

 

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