Angular 可观察的';s订阅触发两次
我对observable的订阅有问题。我有一个Angular 可观察的';s订阅触发两次,angular,observable,subscribe,Angular,Observable,Subscribe,我对observable的订阅有问题。我有一个NotificationService,用于将响应中的任何组件的数据传输到NotificationComponent。现在我只需要订阅一次,但我得到两次 这是我的通知服务: export class NotificationSharedService { private emitChangeSource = new Subject<any>(); changeEmitted = this.emitChangeSource.
NotificationService
,用于将响应中的任何组件的数据传输到NotificationComponent
。现在我只需要订阅一次,但我得到两次
这是我的通知服务:
export class NotificationSharedService {
private emitChangeSource = new Subject<any>();
changeEmitted = this.emitChangeSource.asObservable();
emitChange(change: any) {
console.log(change);
this.emitChangeSource.next(change);
}
getData(): Observable<any> {
return this.changeEmitted;
}
}
const setDefaultImageRequest = this.images.defaultImage(id_image)
.map((data: ResponseService) => {
return Image.createFromObject(data.data);
})
.subscribe((data) => {
console.log(data);
this.defaultImage.id = data.id;
this.propertyGalleryStatus = true;
const status = {
'message': 'Изображение по-умолчанию установлено успешно',
'status': true
};
this.notificationShared.emitChange(status);
}, (errors) => {
console.log(errors);
this.propertyGalleryStatus = true;
});
this.subscriptions.push(setDefaultImageRequest);
constructor(public sharedData: NotificationSharedService) {
const getSharedData = this.sharedData.getData().subscribe((data) => {
console.log(data);
this.status = false;
this.statusError = false;
this.state = true;
if (data.internet_connection !== undefined) {
if (!data.internet_connection) {
console.log(data);
this.message = this.messages.internet_error;
this.statusError = data.statusError;
console.log(this.message);
return;
}
}
this.message = data.message;
this.status = data.status;
this.statusError = data.statusError;
this.fadeNotification = setTimeout(() => {
this.state = false;
setTimeout(() => {
this.status = false;
}, 5000);
this.statusError = false;
}, 4000);
});
this.subscriptions.push(getSharedData);
}
这是我订阅的通知组件:
export class NotificationSharedService {
private emitChangeSource = new Subject<any>();
changeEmitted = this.emitChangeSource.asObservable();
emitChange(change: any) {
console.log(change);
this.emitChangeSource.next(change);
}
getData(): Observable<any> {
return this.changeEmitted;
}
}
const setDefaultImageRequest = this.images.defaultImage(id_image)
.map((data: ResponseService) => {
return Image.createFromObject(data.data);
})
.subscribe((data) => {
console.log(data);
this.defaultImage.id = data.id;
this.propertyGalleryStatus = true;
const status = {
'message': 'Изображение по-умолчанию установлено успешно',
'status': true
};
this.notificationShared.emitChange(status);
}, (errors) => {
console.log(errors);
this.propertyGalleryStatus = true;
});
this.subscriptions.push(setDefaultImageRequest);
constructor(public sharedData: NotificationSharedService) {
const getSharedData = this.sharedData.getData().subscribe((data) => {
console.log(data);
this.status = false;
this.statusError = false;
this.state = true;
if (data.internet_connection !== undefined) {
if (!data.internet_connection) {
console.log(data);
this.message = this.messages.internet_error;
this.statusError = data.statusError;
console.log(this.message);
return;
}
}
this.message = data.message;
this.status = data.status;
this.statusError = data.statusError;
this.fadeNotification = setTimeout(() => {
this.state = false;
setTimeout(() => {
this.status = false;
}, 5000);
this.statusError = false;
}, 4000);
});
this.subscriptions.push(getSharedData);
}
这里是订阅触发两次的响应:
export class NotificationSharedService {
private emitChangeSource = new Subject<any>();
changeEmitted = this.emitChangeSource.asObservable();
emitChange(change: any) {
console.log(change);
this.emitChangeSource.next(change);
}
getData(): Observable<any> {
return this.changeEmitted;
}
}
const setDefaultImageRequest = this.images.defaultImage(id_image)
.map((data: ResponseService) => {
return Image.createFromObject(data.data);
})
.subscribe((data) => {
console.log(data);
this.defaultImage.id = data.id;
this.propertyGalleryStatus = true;
const status = {
'message': 'Изображение по-умолчанию установлено успешно',
'status': true
};
this.notificationShared.emitChange(status);
}, (errors) => {
console.log(errors);
this.propertyGalleryStatus = true;
});
this.subscriptions.push(setDefaultImageRequest);
constructor(public sharedData: NotificationSharedService) {
const getSharedData = this.sharedData.getData().subscribe((data) => {
console.log(data);
this.status = false;
this.statusError = false;
this.state = true;
if (data.internet_connection !== undefined) {
if (!data.internet_connection) {
console.log(data);
this.message = this.messages.internet_error;
this.statusError = data.statusError;
console.log(this.message);
return;
}
}
this.message = data.message;
this.status = data.status;
this.statusError = data.statusError;
this.fadeNotification = setTimeout(() => {
this.state = false;
setTimeout(() => {
this.status = false;
}, 5000);
this.statusError = false;
}, 4000);
});
this.subscriptions.push(getSharedData);
}
这是两次触发通知模板的屏幕截图:
这是通知模板
<div on-mouseover="hoverNotification()" on-mouseout="unhoverNotification()" [ngClass]="{sbNotificationActive: state, sbNotificationSuccess: status, sbNotificationFailure: statusError}" class="sb-notification">
<div class="sb-notification__wrapper">
<div class="sb-notification__box">
<span class="sb-notification__message">{{message}}</span>
<a *ngIf="!linkStatus" role="button" (click)="reloadPage()" class="sb-notification__reload">Reload page</a>
</div>
<div (click)="close()" class="sb-notification__close-button">
<i class="sb-notification__icon flaticon-cancel"></i>
</div>
</div>
{{message}}
重新加载页面
您可以使用简单标志来防止这种情况
this.isDataLoaded = false;
// use OnInit instead of constructor
constructor(public sharedData: NotificationSharedService) {
const getSharedData = this.sharedData.getData().subscribe((data) => {
console.log(data);
if(this.isDataLoaded) { this.isDataLoaded = false; return; }
if(!this.isDataLoaded) {
this.isDataLoaded = true;
// do other stuff
}
}
您不能从订阅一个可观察对象的订阅中获得多个输出。你的服务是单身。在您的通知服务中此
控制台.log(更改)代码>和在通知组件中此控制台.log(数据)代码>多次打印该消息。从NotificationService中删除console.log()
,您应该只看到一个输出。在屏幕截图上,您可以看到控制台只在第29行触发了两次。我添加了新的屏幕截图,您可以在其中看到两次触发的通知div。您可以展示如何将数据放入模板吗?好像它打印了两次,这意味着有两个订阅是的,当然。我加了一句。你如何显示通知?因为这个模板被渲染了两次,对吗?如何打开它?在NotificationComponent中显示@Component decorator。