input type=file实现图片上传，预览以及图片删除

// html

<div class="preview" v-show="previewImg" @click="previewImg=''"><img :src="previewImg" alt="" /></div>
<div class="uploadBox2">
   <div class="uploadBtn uploadImg" v-for="(item,index) in imgDatas">
       <span class="close" @click="deleteImg(index)">✕</span>
       <img :src="item" alt="" @click="previewImg=item">
   </div>
　　<div class="uploadBtn">
    　　<span class="iconadd">+</span>
    　　<input type="file" accept="image/*" multiple @change="changeImage($event)"/>
　　</div>
</div>

// css

.uploadBox2{
  display: flex;
  display: -webkit-flex;
  flex-wrap: wrap;
  -webkit-flex-wrap: wrap;
}
.uploadBtn{
  width: 60px;
  height: 60px;
  border: 1px dashed #E6E6E6;
  position: relative;
  margin: 0 8px 15px 0;
}
.uploadImg{
  border: none;
}
.uploadBtn img{
  width: 100%;
  height: 100%;
}
.uploadBtn input{
  width: 100%;
  height: 100%;
  opacity: 0;
}
.close{
  width: 15px;
  height: 15px;
  line-height: 15px;
  text-align: center;
  position: absolute;
  top: -6px;
  right: -6px;
  color: #fff;
  background: rgba(0,0,0,0.6);
  border-radius: 50%;
  font-size: 10px;
}
.iconadd{
  font-size: 20px;
  color: #E6E6E6;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%,-50%);
  z-index: 0;
}
.preview{
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  z-index: 99;
  background: rgba(0,0,0,0.9);
}
.preview img{
  width: 100%;
  height: 100%;
  object-fit: contain;
  vertical-align: middle;
}

// JS

data(){
  return(){
      filesArr: [],
      imgDatas: [],
      previewImg: '', // 放大预览图片
  }  
},
methods: {
     // 上传图片
    changeImage(e){
      let files = e.target.files;
       // 如果没有选中文件，直接返回
      if (files.length === 0) {
        return;
      }
      let reader;
      let file;
      let imgDatas = this.imgDatas;
      for (let i = 0; i < files.length; i++) {
        file = files[i];
        this.filesArr.push(file);
        reader = new FileReader();
        if (/.(jpe?g|png|gif)$/i.test(file.name)) {
          reader.onload = function(e) {
            if (imgDatas.indexOf(this.result) === -1) { // 判断数组里值相同的无法上传，具体看自己需求
              imgDatas.push(this.result);
            }
          };
          reader.readAsDataURL(file);
        }
      }
      e.target.value = ''// 清空value值防止 同一张图片无法重复提交
    },
    // 删除图片
    deleteImg(index){
      this.filesArr.splice(index,1);
      this.imgDatas.splice(index,1);
      console.log(this.filesArr);
      console.log(this.imgDatas);
    },    
}

最后实现的效果：

（预览放大图片：）