我是Angular的新手。我希望使页面具有动态添加文本输入的功能。我使用FormGroup来解决此问题。这是我的代码:
createInputDynamicly.ts
export class CreateInputsDynamicly implements OnInit {
orderForm: FormGroup;
items: FormArray;
strings: string[];
constructor(private formBuilder: FormBuilder) { }
ngOnInit() {
this.orderForm = this.formBuilder.group({
items: this.formBuilder.array([ this.createItem() ])
});
this.strings.push('');
}
createItem(): FormGroup {
return this.formBuilder.group({
newText: ''
});
}
addItem(): void {
this.items = this.orderForm.get('items') as FormArray;
this.items.push(this.createItem());
this.strings.push('');
}
showString() {
console.log(this.strings);
}
}
createInputDynamicly.html
<div formArrayName="items"
*ngFor="let item of orderForm.get('items').controls; let i = index;">
<div [formGroupName]="i">
<input formControlName="newText" [(ngModel)]="strings[i]">
</div>
</div>
<button (click)="addItem()" type="button">Add new input</button>
<button (click)="showStrings()" type="button">Show</button>
问题是,每当我按下“添加新输入”按钮时,都会在div和添加项方法中得到“无法读取未定义的属性'get'”。我不明白我在做什么错。
这是工作示例
在模板中
<form [formGroup]="orderForm">
<div formArrayName="items">
<div [formGroupName]="i" *ngFor="let item of items.controls; let i = index;">
<input formControlName="newText" >
</div>
</div>
<button (click)="addItem()" type="button">Add new input</button>
<button (click)="showStrings()" type="button">Show</button>
</form>
in .ts
export class CreateInputsDynamicly implements OnInit {
orderForm: FormGroup;
get items(): FormArray {
return this.orderForm.get("items") as FormArray;
}
constructor(private formBuilder: FormBuilder) { }
ngOnInit() {
this.orderForm = this.formBuilder.group({
items: this.formBuilder.array([ this.createItem() ])
});
}
createItem(): FormGroup {
return this.formBuilder.group({
newText: ''
});
}
addItem(): void {
this.items.push(this.createItem());
}
showString() {
console.log( this.items.value);
}
}
strings
未定义,它将产生错误strings
属性,您可以获得this.orderForm.get('items').value
OnInit
导入@angular/core