使用FormData上传单个文件

Question

我要使用此代码上传单个文件：

let formData = new FormData();
let file = this.file[0];
formData.append("file", file);

通常，我使用这段代码是因为当我上传多个文件时：

 let formData = new FormData();
  for (let i = 0; i < data.files.length; i++) {
    let file = data.files[i];
    consol
    formData.append("files[" + i + "]", file);
  }

但是对于单个文件上传，在附加文件后，formData变量保持为空。当我console.log file变量时，它显示以下内容：

File {name: "2020_03_17 21_53 Office Lens (1).jpg", lastModified: 1587394084978, lastModifiedDate: Mon Apr 20 2020 16:48:04 GMT+0200 (Central European Summer Time), webkitRelativePath: "", size: 306890, …}
lastModified: 1587394084978
lastModifiedDate: Mon Apr 20 2020 16:48:04 GMT+0200 (Central European Summer Time) {}
name: "2020_03_17 21_53 Office Lens (1).jpg"
size: 306890
type: "image/jpeg"
webkitRelativePath: ""

为什么不将此文件附加到FormData？

Answer 1

Refer-https://developer.mozilla.org/en-US/docs/Web/API/FormData/Using_FormData_Objects

Answer 2

let formData = new FormData();
let file = this.files[0];
formData.append("file", file);