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我做一個簡單的項目空數組:角2:在組分HTML
有2個輸入滑塊和按鈕「計算」,當按下按鈕時,計算完成和印刷到表中。
我有一個小問題,當我按下按鈕時,表組件顯示答案數組是空的,但如果我從構造函數將它打印到控制檯,一切都會顯示出來。
有人可以幫忙嗎? 我想做一個*ngFor
並稍後循環遍歷元素。
服務:
@Injectable()
export class DataService {
loanArray: Payment[] = [];
setCalculatedPayments(loanSum: number, loanTime:number) {
this.loanArray = new PaymentsCalculated(loanSum, loanTime).calculateLoanDetails();
}
getCalculatedPayments() {
return this.loanArray;
}
}
貸款部分:
export class LoanTablesComponent implements OnInit {
loanArray: Payment[] = []; // is it always empty?
constructor(private DataService: DataService) {
this.loanArray = this.DataService.getCalculatedPayments();
// here it prints the loanArray as required
// but if I print out in the .html, it is always zero
}
ngOnInit() {
}
}
計算部件:
export class CalculatorComponent implements OnInit {
loanSum: number;
loanTime: number;
constructor(private DataService: DataService) {
setTimeout(() => this.loanSum = 500);
setTimeout(() => this.loanTime = 1);
// for input sliders
}
ngOnInit() {
}
calculatePayments(): void{
this.DataService.setCalculatedPayments(this.loanSum, this.loanTime);
}
}
感謝您的幫助,剛開始學習和尋求建議(:
'CalculatorComponent'和'LoanTablesComponent'之間的關係是什麼? – AngularChef
計算器顯示用於計算的輸入的輸入UI,當按下按鈕時它將數據提供給數據服務,貸款表輸出表,從數據服務中取數據 –
好的。但我的意思是他們如何在組件樹**中關聯**? (例如,是否是另一個的孩子?)看起來你有一個時間問題:一旦'LoanTablesComponent'實例化,你嘗試讀取數據,但直到你調用setCalculatedPayments()'它才被設置。如果'loanArray'包含非原始值,我認爲變更檢測不能用於您的設置。也許嘗試用[get property](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/get)替換'LoanTablesComponent'中的'loanArray'? – AngularChef