angular-docs-cn/modules/angular2/docs/cheatsheet/lifecycle hooks.md

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@cheatsheetSection Directive and component change detection and lifecycle hooks @cheatsheetIndex 8 @description (implemented as class methods)

@cheatsheetItem syntax(js ts): constructor(myService: MyService, ...) { ... }|constructor(myService: MyService, ...) syntax(dart): MyAppComponent(MyService myService, ...) { ... }|MyAppComponent(MyService myService, ...) description: The class constructor is called before any other lifecycle hook. Use it to inject dependencies, but avoid any serious work here.

@cheatsheetItem syntax: ngOnChanges(changeRecord) { ... }|ngOnChanges(changeRecord) description: Called after every change to input properties and before processing content or child views.

@cheatsheetItem syntax: ngOnInit() { ... }|ngOnInit() description: Called after the constructor, initializing input properties, and the first call to ngOnChanges.

@cheatsheetItem syntax: ngDoCheck() { ... }|ngDoCheck() description: Called every time that the input properties of a component or a directive are checked. Use it to extend change detection by performing a custom check.

@cheatsheetItem syntax: ngAfterContentInit() { ... }|ngAfterContentInit() description: Called after ngOnInit when the component's or directive's content has been initialized.

@cheatsheetItem syntax: ngAfterContentChecked() { ... }|ngAfterContentChecked() description: Called after every check of the component's or directive's content.

@cheatsheetItem syntax: ngAfterViewInit() { ... }|ngAfterViewInit() description: Called after ngAfterContentInit when the component's view has been initialized. Applies to components only.

@cheatsheetItem syntax: ngAfterViewChecked() { ... }|ngAfterViewChecked() description: Called after every check of the component's view. Applies to components only.

@cheatsheetItem syntax: ngOnDestroy() { ... }|ngOnDestroy() description: Called once, before the instance is destroyed.