响应式表单单选按钮默认值checked

Question

我希望单选按钮的默认值为checked。我尝试了以下操作，但没有成功。

form: FormGroup;
gifts: IGift;
this.form = this.fb.group({
phone: ['', [Validators.required, Validators.pattern('^[0][5][0-9]{8}$')]],
email: ['', [CustomValidators.email]],
k_gift: ['', [Validators.required, CustomValidators.gt(0)]],
});
this._giftService.getUserGifts()
.subscribe(g => {
this.gifts = g;
},
error => {
if (error.includes("401")) {
localStorage.removeItem("token");
location.reload();
})

<input type="radio" [value]="gifts.k_gift" aria-checked="false" attr.id="gift{{gift.k_gift}}" formControlName="k_gift" >
<label class='control-label' attr.for="gift{{gift.k_gift}}">
{{gift.desc_k_gift}}
</label>

插入礼品的值。k_gift是1。我试过[value] = 1，也试过k_gift: [1, [Validators.required, CustomValidators.gt(0)]],也尝试了checked在htmlinput标签。

都不适合我。如何将此单选按钮的默认值设置为checked?

Answer 1

您正在使用模型驱动的表单。在模板中不使用[value]输入，而是相应地设置模型:

this._giftService.getUserGifts()
.subscribe(g => {
// here
this.gifts = g;
this.form.patchValue({ k_gift: /* insert desired value */ });
},