我正在使用FCM进行Topic Messaging on Android。
如果我多次致电/* tslint:disable:component-selector-name component-selector-type */
@Component({
selector: 'datepicker[ngModel]',
template: `
<datepicker-inner [activeDate]="activeDate"
(update)="onUpdate($event)"
[datepickerMode]="datepickerMode"
[initDate]="initDate"
[minDate]="minDate"
[maxDate]="maxDate"
[minMode]="minMode"
[maxMode]="maxMode"
[showWeeks]="showWeeks"
[formatDay]="formatDay"
[formatMonth]="formatMonth"
[formatYear]="formatYear"
[formatDayHeader]="formatDayHeader"
[formatDayTitle]="formatDayTitle"
[formatMonthTitle]="formatMonthTitle"
[startingDay]="startingDay"
[yearRange]="yearRange"
[customClass]="customClass"
[dateDisabled]="dateDisabled"
[onlyCurrentMonth]="onlyCurrentMonth"
[shortcutPropagation]="shortcutPropagation"
(selectionDone)="onSelectionDone($event)">
<daypicker tabindex="0"></daypicker>
<monthpicker tabindex="0"></monthpicker>
<yearpicker tabindex="0"></yearpicker>
</datepicker-inner>
`,
providers: [NgModel]
})
/* tslint:enable:component-selector-name component-selector-type */
export class DatePickerComponent implements ControlValueAccessor {
@Input() public datepickerMode:string;
@Input() public initDate:Date;
@Input() public minDate:Date;
@Input() public maxDate:Date;
@Input() public minMode:string;
@Input() public maxMode:string;
@Input() public showWeeks:boolean;
@Input() public formatDay:string;
@Input() public formatMonth:string;
@Input() public formatYear:string;
@Input() public formatDayHeader:string;
@Input() public formatDayTitle:string;
@Input() public formatMonthTitle:string;
@Input() public startingDay:number;
@Input() public yearRange:number;
@Input() public onlyCurrentMonth:boolean;
@Input() public shortcutPropagation:boolean;
@Input() public customClass:Array<{date:Date, mode:string, clazz:string}>;
// todo: change type during implementation
@Input() public dateDisabled:any;
@Output() public selectionDone:EventEmitter<Date> = new EventEmitter<Date>(undefined);
public onChange:any = Function.prototype;
public onTouched:any = Function.prototype;
public cd:NgModel;
private _now:Date = new Date();
private _activeDate:Date;
@ViewChild(DatePickerInnerComponent) private datePicker: DatePickerInnerComponent;
@Input()
public get activeDate():Date {
return this._activeDate || this._now;
}
public constructor(@Self() cd:NgModel) {
this.cd = cd;
// hack
cd.valueAccessor = this;
}
public set activeDate(value:Date) {
this._activeDate = value;
}
public onUpdate(event:any):void {
this.cd.viewToModelUpdate(event);
}
public onSelectionDone(event:Date):void {
this.selectionDone.emit(event);
}
// todo: support null value
public writeValue(value:any):void {
if (this.datePicker.compare(value, this._activeDate) === 0) {
return;
}
if (value && value instanceof Date) {
this.activeDate = value;
this.datePicker.select(value);
return;
}
this.activeDate = value ? new Date(value) : void 0;
}
public registerOnChange(fn:(_:any) => {}):void {
this.onChange = fn;
}
public registerOnTouched(fn:() => {}):void {
this.onTouched = fn;
}
}
订阅新闻＆＃39;话题，会发生什么？
我花了很多时间寻找它，但我不能。我在我的MainActivity中使用该方法，因此每次启动应用程序时都会调用它。根据我的经验，获取推送消息并不是问题，我还无法找到任何问题。但是当我多次打电话时，我想知道它。
答案 0 :(得分：7)
您只能订阅一次主题。
对同一主题的subscribeToTopic()的额外调用基本上是禁止操作，它们没有区别。