<div class="model-mask" v-show="show">
  <div :class="[type === 'top' " @click="close">
   <div :class="[type === 'top' "
    :style="{width:width + 'px'}">
    <div class="model-header">
     <span>{{title}}</span>
     <i class="close-empty" @click="close">
      <Icon
       type="ivu-icon ivu-icon-ios-close-empty"
       size="25" />
     </i>
    </div>
    <div class="model-body">
     <slot></slot>
    </div>
   </div>
  </div>
 </div>

 export default {
 name: 'MyModel',
 props:
 {
  title: String,
  show: Boolean,
  width: Number,
  type: String
 },
 data () {
  return {
   scrollTop: ''
  }
 },
 watch: {
  show: function (val, oldVal) {
   function getScrollTop () {
    return document.body.scrollTop || document.documentElement.scrollTop
   }
   if (val) {
    // 在弹出层显示之前，记录当前的滚动位置
    this.scrollTop = getScrollTop()
    let body = document.querySelector('body')
    body.className = 'not-scroll'
    // 把脱离文档流的body拉上去！否则页面会回到顶部！
    document.body.style.top = -this.scrollTop + 'px'
   }
  }
 },
 methods: {
  close: function (e) {
   function to (scrollTop) {
    document.body.scrollTop = document.documentElement.scrollTop = scrollTop
   }
   let target = e.srcElement || e.target
   if (target.className === 'model-wrapper' ||
     target.className.indexOf('ivu-icon-ios-close-empty') > -1 ||
     target.className === 'model-wrapper-top') {
    this.$emit('close')
    let body = document.querySelector('body')
    body.className = ''
    // 滚回到老地方！
    to(this.scrollTop)
   }
  }
 }
}

 <style scoped lang="scss">
.model-mask {
 height: 100%;
 position: fixed;
 top: 0;
 bottom: 0;
 left: 0;
 right: 0;
 z-index: 1000;
 background: rgba(0, 0, 0, .5);
}
/**
 * 垂直居中
 */
.model-wrapper {
 height: 100%;
 text-align: center;
}
.model-wrapper:before {
 content: "";
 display: inline-block;
 height: 100%;
 vertical-align: middle;
}
.model-container {
 position: relative;
 display: inline-block;
 vertical-align: middle;
 background-color: white;
 text-align: left;
 box-shadow: 0 5px 14px 0 rgba(0,0,0,0.15);
 border-radius: 6px;
 overflow: hidden;
 z-index: 1050;
}
/**
 * 距离顶部100px，可滚动
 */
.model-wrapper-top {
 position: relative;
 height: 100%;
 overflow-x: hidden;
 overflow-y: scroll;
}
.model-container-top {
 margin: 100px auto;
 background-color: white;
 text-align: left;
 box-shadow: 0 5px 14px 0 rgba(0,0,0,0.15);
 border-radius: 6px;
 overflow: hidden;
}
.close-empty {
 position: absolute;
 right: 16px;
 top: 10px;
 overflow: hidden;
 cursor: pointer;
 z-index: 1100;
}
.model-header {
 position: relative;
 height: 45px;
 line-height: 45px;
 padding: 0 20px;
 font-size: 14px;
 color: #999;
 border-bottom: 1px solid #eee;
}
</style>

 <button type="button" @click="showModel">戳我呀</button>
import MyModel from '../componets/model.vue'
export default {
 name: 'test',
 components: {
  MyModel
 },
 data () {
  return {
   show: false
  }
 },
 methods: {
  /**
   * 打开model
   */
  closeModel: function () {
   this.show = false
  },
  /**
   * 关闭model
   */
  showModel: function () {
   this.show = true
  }
 }
}

 <my-model title="标题" :width="400" :show="show" v-on:close="closeModel">
   <!-- slot -->
   <div class="tips">
     <p>this is content area。</p>
   </div>
  </my-model>

 <my-model type="top" title="标题" :width="400" :show="show" v-on:close="closeModel">
   <!-- slot -->
   <div class="tips">
     <p v-for="i in 50">this is content area。</p>
   </div>
  </my-model>