<el-upload
            drag
            multiple
            class="drawing-upload"
            show-file-list
            :action="FileModel.uploadObjectUrl"
            :http-request="httpRequest"
            :limit="50"
            :file-list="fileList"
            :on-remove="handleRemove"
            :on
 
-success="handleSuccess"
            :on-error="handleError"
            :before-upload="beforeUpload"
            :on-exceed="exceed"
        >
            <div class="upload-handle-text">
                <div class="el-icon-upload" />
                <div class="upload-tips">拖拽或上傳圖紙檔案</div>
            </div>
</el-upload>

/**
 * 自定義上傳
 */
httpRequest (file) {
    const formData = new FormData()
    formData.append('file', file.file)
    const extension = file.file.name.indexOf('.') > -1
        ? `.${file.file.name.split('.').pop()}`
        : ''
    // http-request 進度條
    if (uploadSetting.zip.indexOf(extension) > -1) {
        // FileModel.compressPackageFilterUpload為封裝的axios
        return FileModel.compressPackageFilterUpload(formData, this.supportFileType, {
            onUploadProgress: (progressEvent) => {
 

                const num = progressEvent.loaded / progressEvent.total * 100 | 0
                file.onProgress({ percent: num })
            }
        })
    } else {
        // FileModel.uploadObject為封裝的axios
        return FileModel.uploadObject(formData, {
            onUploadProgress: (progressEvent) => {
                const num = progressEvent.loaded / progressEvent.total * 100 | 0
                file.onProgress({ percent: num })
            }
        })
    }
},

// 上傳檔案(表單上傳，MultipartFile形式),返回檔案物件
uploadObject (formData, config) {
    // 注意檔案系統不需要加 apis 字首
    return request.post(`${methodsPrefix}/file-systems/multipart-file/file-system`, formData, {
        headers: { 'Content-Type': 'multipart/form-data' },
        ...config
    })
}

el-upload 使用 http-request的時候，進度條會不顯示。要想顯示進度條，所以在http-request的時候要加上onUploadProgress監聽進度，然後呼叫餓了麼的檔案物件file.onProgress({ percent: num })更新進度，

有必要的話還需要呼叫file.onSuccess()方法更新檔案上傳成功狀態