我使用ng2-tel-input与反应形式方法（Angular） .

Issue:
当我打开标记下拉列表并选择一个值时，它工作正常 . 值正确显示在输入中，但国家标志不会更改，并显示默认标志 .

当我在输入中手动更改值时，标志会自动更改，否则显示默认国家标志 .

Example:
值格式： +917878747474
所选国家： India
默认国家/地区： us

when i press on set value. phone no set on input but flag remain same

html

<form [formGroup]="form">
        <small class="phone-text">{{ placeHolder }}</small>
        <md-input-container class="full-width pt-0">
            <input type="text"
                   mdInput
                   formControlName="phone"
                   ng2TelInput
                   [ng2TelInputOptions]="{initialCountry: initialCountry}"
                   (hasError)="hasError($event)"
                   (ng2TelOutput)="hasOutPut($event)"
                   #phoneInput
                   maxlength="45"/>
        </md-input-container>
       <button type="button" (click)="setValue()">Set Value</button>
    </form>

Component

import {Attribute, Component, forwardRef, Input} from '@angular/core';
import {FormBuilder, FormGroup} from '@angular/forms';

@Component({
    selector: 'app-phone',
    templateUrl: './phone.component.html',
    styleUrls: ['./phone.component.scss']
})
export class PhoneComponent implements ControlValueAccessor, Validator {
    placeHolder = 'Default Value';
    initialCountry = 'us';
    form: FormGroup;

    constructor(private _fb: FormBuilder) {
        this._initForm();
    }

    setValue(): void {
        const phone = '+917878747416'
        this.form.setValue({phone: phone});
    }

    private _initForm(): void {
        this.form = this._fb.group({
            'phone': ['']
        });
    }

    hasError(event: any): void {
        if (!event && this.form.value.phone !== '') {
            this.form.get('phone').setErrors(['invalid_cell_phone', true]);
        }
    }

    hasOutPut(event: any): void {
        this.form.patchValue({phone: event});
    }
}

任何帮助，将不胜感激 .

angular