Global Library Installation

全局库安装

Some javascript libraries need to be added to the global scope and loaded as if
they were in a script tag.
We can do this using the scripts and styles options of the build target in angular.json.
一些JavaScript库需要被添加到全局范围并加载，就好像它们在脚本标签中一样，我们可以使用angular.json中构建目标的脚本和样式选项来完成此操作。

As an example, to use Bootstrap 4
this is what you need to do:
例如，要使用Bootstrap 4，您需要执行以下操作：

First install Bootstrap from npm:
首先从 npm 安装Bootstrap：

npm install jquery --save
npm install popper.js --save
npm install bootstrap --save

Then add the needed script files to scripts:
然后将所需的脚本文件添加到 scripts 中:

"scripts": [
  "node_modules/jquery/dist/jquery.slim.js",
  "node_modules/popper.js/dist/umd/popper.js",
  "node_modules/bootstrap/dist/js/bootstrap.js"
],

Finally add the Bootstrap CSS to the styles array:
最后，将Bootstrap CSS添加到 styles 数组中：

"styles": [
  "node_modules/bootstrap/dist/css/bootstrap.css",
  "src/styles.css"
],

Restart ng serve if you're running it, and Bootstrap 4 should be working on your app.
如果您正在运行它，请重新启动服务，并且Bootstrap 4应该在您的应用程序上运行。