为了防止浏览器刷新，关闭窗口等（有关问题的详细信息，请参见@ChristopheVidal对Günter的回答的评论），我发现将@HostListener装饰器添加到类的canDeactivate实现中以侦听beforeunload window事件也很有帮助。如果配置正确，则可以同时防止应用内和外部导航。
例如：
零件：
import { ComponentCanDeactivate } from './pending-changes.guard';
import { HostListener } from '@angular/core';
import { Observable } from 'rxjs/Observable';
export class MyComponent implements ComponentCanDeactivate {
// @HostListener allows us to also guard against browser refresh, close, etc.
@HostListener('window:beforeunload')
canDeactivate(): Observable<boolean> | boolean {
// insert logic to check if there are pending changes here;
// returning true will navigate without confirmation
// returning false will show a confirm dialog before navigating away
}
}
守卫：
import { CanDeactivate } from '@angular/router';
import { Injectable } from '@angular/core';
import { Observable } from 'rxjs/Observable';
export interface ComponentCanDeactivate {
canDeactivate: () => boolean | Observable<boolean>;
}
@Injectable()
export class PendingChangesGuard implements CanDeactivate<ComponentCanDeactivate> {
canDeactivate(component: ComponentCanDeactivate): boolean | Observable<boolean> {
// if there are no pending changes, just allow deactivation; else confirm first
return component.canDeactivate() ?
true :
// NOTE: this warning message will only be shown when navigating elsewhere within your angular app;
// when navigating away from your angular app, the browser will show a generic warning message
// see http://stackoverflow.com/a/42207299/7307355
confirm('WARNING: You have unsaved changes. Press Cancel to go back and save these changes, or OK to lose these changes.');
}
}
路线：
import { PendingChangesGuard } from './pending-changes.guard';
import { MyComponent } from './my.component';
import { Routes } from '@angular/router';
export const MY_ROUTES: Routes = [
{ path: '', component: MyComponent, canDeactivate: [PendingChangesGuard] },
];
模块：
import { PendingChangesGuard } from './pending-changes.guard';
import { NgModule } from '@angular/core';
@NgModule({
// ...
providers: [PendingChangesGuard],
// ...
})
export class AppModule {}
注意：正如@JasperRisseeuw所指出的那样，IE和Edge处理beforeunload事件的方式与其他浏览器不同，并且false在beforeunload事件激活时（例如，浏览器刷新，关闭窗口等），将在确认对话框中包含单词。在Angular应用中导航不会受影响，并且会正确显示您指定的确认警告消息。那些需要支持IE / Edge并不想false在beforeunload事件激活时在确认对话框中显示/想要更详细的消息的人可能还希望查看@JasperRisseeuw的解决方案。