angular-docs-cn/public/docs/_examples/router/ts/app/dialog.service.ts

// #docregion
import { Injectable } from '@angular/core';
/**
 * Async modal dialog service
 * DialogService makes this app easier to test by faking this service.
 * TODO: better modal implemenation that doesn't use window.confirm
 */
@Injectable()
export class DialogService {
  /**
   * Ask user to confirm an action. `message` explains the action and choices.
   * Returns promise resolving to `true`=confirm or `false`=cancel
   */
  confirm(message?: string) {
    return new Promise<boolean>((resolve, reject) =>
      resolve(window.confirm(message || 'Is it OK?')));
  };
}