如何添加依赖项以做出反应？

Question

我正在尝试将以下库添加到react项目：

https://github.com/rndme/download

我已经完成了以下工作：

yarn add https://github.com/rndme/download

并得到此回复：

info No lockfile found.
[1/4] 🔍  Resolving packages...
[2/4] 🚚  Fetching packages...
[3/4] 🔗  Linking dependencies...
[4/4] 🔨  Building fresh packages...
success Saved lockfile.
success Saved 1 new dependency.
info Direct dependencies
└─ [email protected]
info All dependencies
└─ [email protected]
✨  Done in 2.19s.

然后我更新了package.json以包含它：

  "dependencies": {
    "bootstrap": "4.1.3",
    "react": "^16.6.0",
    "react-cookie": "3.0.4",
    "react-dom": "^16.6.0",
    "react-router-dom": "4.3.1",
    "react-scripts": "2.1.0",
    "reactstrap": "6.5.0",
    "downloadjs": "1.4.8"
  },

并添加了一些代码来调用它：

  async downloadFile(file, url) {
    const res = await fetch(url);
    const blob = res.blob();

    // from downloadjs it will download your file
    download(blob, file, "text/plain");  
  }

但是，它无法编译：

Failed to compile
./src/LicenseList.js
  Line 64:  'download' is not defined  no-undef

知道为什么吗？

Answer 1

[运行yarn add <dependency>时，所需的依赖项实际上已添加到package.json，然后下载到node_modules文件夹中。在这种情况下，您不必手动更新package.json。您是否在项目的根文件夹中执行了yarn add？这是必不可少的。