Angular 在表单数组(被动表单)中添加和删除输入字段
我有一个局部变量,其中后端数据作为数组接收,如下所示:Angular 在表单数组(被动表单)中添加和删除输入字段,angular,angular7,reactive-forms,Angular,Angular7,Reactive Forms,我有一个局部变量,其中后端数据作为数组接收,如下所示: itemsFromBackend: ["Item1", "Item2"] 创建新数组 items: FormArray 在formgroup中: ngOnInit() { this.form = this.formBuilder.group({ items: this.formBuilder.array([ this.createItem() ]) }); } 创建项目 createItem(): FormGroup
itemsFromBackend: ["Item1", "Item2"]
创建新数组
items: FormArray
在formgroup中:
ngOnInit() {
this.form = this.formBuilder.group({
items: this.formBuilder.array([ this.createItem() ])
});
}
创建项目
createItem(): FormGroup {
return this.formBuilder.group({
name: ''
});
}
添加项目:
addItem(): void {
this.items = this.form.get('items') as FormArray;
this.items.push(this.createItem());
}
在HTML中
<div formArrayName="items" *ngFor="let item of form.get('items').controls; let i = index ">
<div *ngFor="let item of itemsFromBackEnd" [formGroupName]="i">
<input value={{item}} />
<section>
<button
mat-raised-button
color="primary"
type="button"
(click)="addItem()"
>
<i class="material-icons"> add </i>
</button>
</section>
</div>
</div>
添加
我现在收到两个带有后端值的字段,但是当我单击add按钮时,它应该会显示一个新的输入字段,但是它正在添加另外两个带有后端值的输入字段。当我点击add按钮时,我需要一些帮助来显示一个新的输入字段。谢谢。通过这些更改,它将按照您的要求运行 html:
添加
ts:
itemsfrombend=['Item1','Item2'];
表格:表格组;
构造函数(私有formBuilder:formBuilder){}
恩戈尼尼特(){
this.form=this.formBuilder.group({
项:this.formBuilder.array([])
});
this.itemsfrombend.forEach(i=>this.addItem(i));
}
getItems(){
return(this.form.get('items')).controls;
}
itemValue(项目:任何){
返回item.controls.value.value;
}
createItem(名称?:字符串):FormGroup{
返回此.formBuilder.group({
值:名称?名称:“”
});
}
附加项(名称?:字符串):无效{
const items=this.form.get('items')作为FormArray;
items.push(this.createItem(name));
}
<div [formGroup]="form">
<div formArrayName="items" *ngFor="let item of getItems(); let i = index">
<input value="{{ itemValue(item) }}" />
</div>
<section>
<button mat-raised-button color="primary" type="button" (click)="addItem()">
<i class="material-icons"> add </i>
</button>
</section>
</div>
itemsFromBackEnd = ['Item1', 'Item2'];
form: FormGroup;
constructor(private formBuilder: FormBuilder) {}
ngOnInit() {
this.form = this.formBuilder.group({
items: this.formBuilder.array([])
});
this.itemsFromBackEnd.forEach(i => this.addItem(i));
}
getItems() {
return (<FormArray>this.form.get('items')).controls;
}
itemValue(item: any) {
return item.controls.value.value;
}
createItem(name?: string): FormGroup {
return this.formBuilder.group({
value: name ? name : ''
});
}
addItem(name?: string): void {
const items = this.form.get('items') as FormArray;
items.push(this.createItem(name));
}