ngOnInit varible change爲什麼不影響角度爲2/4的html？

Question

我有用戶對象，我訂閱。如果用戶等於某個名稱，則不應顯示按鈕。我不知道爲什麼它不會影響html中的ngIf。

我的HTML

<input *ngIf = "showDelete" type = "button" (click) = 
"deleteCustomer(customer._id)" value = "Delete" class = "btn btn-danger"> 

我ngOnInit在appcomponent.ts

ngOnInit() { 

let showDelete:boolean =true; 

this.authService.getProfile().subscribe(profile => { 
    this.username = profile.user.name 

    if (this.username=="admin"){ 

    showDelete=false; 
    } 
}, 

如果我CONSOLE.LOG的this.username並顯示刪除我得到的預期值，但不改變html中的邏輯

Answer 1

您應該聲明showDelete變量作爲組件的一部分，以便可以從模板訪問該變量：

public showDelete: boolean = true; 

ngOnInit(): void { 
    this.authService.getProfile().subscribe(profile => { 
     this.username = profile.user.name; 
     if (this.username == "admin") { 
      this.showDelete = false; 
     } 
    }); 
} 

Answer 2

你必須從模板的showDelete進不去，因爲它是內ngOnInit（）定義

嘗試定義這樣的：

class MyClass { 
    showDelete:boolean; 

    ngOnInit() { 
    this.authService.getProfile().subscribe(profile => { 
     this.username = profile.user.name 
     if (this.username=="admin"){ 
     this.showDelete = false; 
     } 
    } 
}