问题的解决方法是使用ngOnChanges钩子，并在新值被检测到时手动更新FormControl的值。下面是示例代码：

@Component({ selector: 'app-custom-input', template: , providers: [ { provide: NG_VALUE_ACCESSOR, useExisting: forwardRef(() => CustomInputComponent), multi: true } ], }) export class CustomInputComponent implements ControlValueAccessor, OnChanges { @Input() placeholder: string; @Input() disabled: boolean; @Output() valueChange = new EventEmitter(); onChange: (value: string) => void = () => {}; onTouched = () => {}; value: string;

ngOnChanges(changes: SimpleChanges) { if (changes.value && changes.value.currentValue !== this.value) { this.value = changes.value.currentValue; this.onChange(this.value); this.valueChange.emit(this.value); } }

writeValue(value: string) { this.value = value; }

registerOnChange(fn: (value: string) => void) { this.onChange = fn; }

registerOnTouched(fn: () => {}) { this.onTouched = fn; }

onBlur() { this.onTouched(); } }

使用上面的代码，就可以在使用自定义mat-input组件时更新FormGroup中FormControl的值。