angular-docs-cn/aio/content/guide/ivy.md

Opting into Angular Ivy

Ivy is the code name for Angular's next-generation compilation and rendering pipeline. Starting with Angular version 8, you can choose to opt in to start using a preview version of Ivy and help in its continuing development and tuning.

To preview Ivy, use @angular/core@next version of Angular (8.1.x), rather than @angular/core@latest (8.0.x), as it contains all the latest bug fixes and improvements.

Using Ivy in a new project

To start a new project with Ivy enabled, use the --enable-ivy flag with the ng new command:

ng new shiny-ivy-app --enable-ivy

The new project is automatically configured for Ivy. Specifically, the enableIvy option is set to true in the project's tsconfig.app.json file.

Using Ivy in an existing project

To update an existing project to use Ivy, set the enableIvy option in the angularCompilerOptions in your project's tsconfig.app.json.

{
  "compilerOptions": { ... },
  "angularCompilerOptions": {
    "enableIvy": true
  }
}

AOT compilation with Ivy is faster and should be used by default. In the angular.json workspace configuration file, set the default build options for your project to always use AOT compilation.

{
  "projects": {
    "my-existing-project": {
      "architect": {
        "build": {
          "options": {
            ...
            "aot": true,
          }
        }
      }
    }
  }
}

To stop using the Ivy compiler, set enableIvy to false in tsconfig.app.json, or remove it completely. Also remove "aot": true from your default build options if you didn't have it there before.