angular-docs-cn/modules/@angular/docs/cheatsheet/class-decorators.md

@cheatsheetSection
Class decorators
@cheatsheetIndex 4
@description
{@target ts}`import {Directive, ...} from '@angular/core';`{@endtarget}
{@target js}Available from the `ng.core` namespace{@endtarget}
{@target dart}`import 'package:angular2/core.dart';`{@endtarget}

@cheatsheetItem
syntax(ts):
`@Component({...})
class MyComponent() {}`|`@Component({...})`
syntax(js):
`var MyComponent = ng.core.Component({...}).Class({...})`|`ng.core.Component({...})`
syntax(dart):
`@Component(...)
class MyComponent() {}`|`@Component(...)`
description:
Declares that a class is a component and provides metadata about the component.

@cheatsheetItem
syntax(ts):
`@Directive({...})
class MyDirective() {}`|`@Directive({...})`
syntax(js):
`var MyDirective = ng.core.Directive({...}).Class({...})`|`ng.core.Directive({...})`
syntax(dart):
`@Directive(...)
class MyDirective() {}`|`@Directive(...)`
description:
Declares that a class is a directive and provides metadata about the directive.

@cheatsheetItem
syntax(ts):
`@Pipe({...})
class MyPipe() {}`|`@Pipe({...})`
syntax(js):
`var MyPipe = ng.core.Pipe({...}).Class({...})`|`ng.core.Pipe({...})`
syntax(dart):
`@Pipe(...)
class MyPipe() {}`|`@Pipe(...)`
description:
Declares that a class is a pipe and provides metadata about the pipe.

@cheatsheetItem
syntax(ts):
`@Injectable()
class MyService() {}`|`@Injectable()`
syntax(js):
`var OtherService = ng.core.Class({constructor: function() { }});
var MyService = ng.core.Class({constructor: [OtherService, function(otherService) { }]});`|`var MyService = ng.core.Class({constructor: [OtherService, function(otherService) { }]});`
syntax(dart):
`@Injectable()
class MyService() {}`|`@Injectable()`
description:
{@target ts dart}Declares that a class has dependencies that should be injected into the constructor when the dependency injector is creating an instance of this class.
{@endtarget}
{@target js}
Declares a service to inject into a class by providing an array with the services with the final item being the function which will receive the injected services.
{@endtarget}