<input
       id="fileInput"
       type="file"
       @change="onSelectFileInputChange"
       @drag.stop
        @dragover.stop
        style="display: none;"
        :multiple="false" //设为true时可以同时上传多个文件
         accept="image/png" //限制上传的文件类型
         title=""
 / >

 mounted() {
    // 防止拖拽时容器奔溃,要阻止拖拽事件的默认行为
    const dragArr = ['dragenter', 'dragover', 'drop']
    dragArr.forEach((name) => {
      document.addEventListener(name, (event) => {
        event.preventDefault()
      })
      this.$once('hook:beforeDestroy', () => {
        document.removeEventListener(name, (event) => {
          event.preventDefault()
        })
      })
    })
  },

    // 拖拽更新文档
    onSelectFileInputChange(e) {
      const files = e?.target?.files
      if (!files.length) {
        return
      }
      const file = files[0]
      const path = e?.target
      this.getFileInfo(file)
    },

    // 分块读取文件,不然文件太大会读取失败
    readFileInChunks(file, callback) {
      const chunkSize = 2097152; // 2MB
      const fileSize = file.size;
      let offset = 0;
      const reader = new FileReader();
      reader.onload = function (e) {
        // 继续读取剩余部分
        offset += chunkSize;
        if (offset < fileSize) {
          reader.readAsDataURL(file.slice(offset, offset + chunkSize));
        } else {
          callback({ data: reader, error: false })
        }
      };

      reader.onerror = function () {
        callback({ data: null, error: true })
      };

      // 开始读取第一块
      reader.readAsDataURL(file.slice(offset, offset + chunkSize));
    },
  //获取文件信息
   getFileInfo(file) {
      return new Promise(async (resolve) => {
        if (!file || !file.size || !file.name) {
          resolve(null)
          return
        }
        this.readFileInChunks(file, (result) => {
          if (result.error) {
            return
          }
          //获取到文件的base64
          const content = result.data.result
        })
      })
    },

// 更改拖拽时的图标
#fileInput::file-selector-button {
  background-image: url('path_to_your_icon.png');
  background-size: contain;
  background-repeat: no-repeat;
  height: 30px; /* 设置按钮的高度 */
  width: 100px; /* 设置按钮的宽度 */
  border: 1px solid #999; /* 设置按钮的边框 */
  color: #333; /* 设置按钮的文本颜色 */
  padding: 5px 10px; /* 设置按钮内的填充 */
}
 
#fileInput {
  /* 隐藏默认的文件选择控件 */
  position: absolute;
  clip: rect(0, 0, 0, 0);
}