changed property

MySelectorValueChanged<T>? get changed

用户做出了明确操作时返回 MySelectorValueChanged，否则返回 null。

比 switch 更简洁的用法：

final result = await MySelector.show<String>(...);
final changed = result.changed;
if (changed != null) {
  selectedItem = changed.item; // 直接获取完整 item，无需 firstWhere
}

Implementation

MySelectorValueChanged<T>? get changed => this is MySelectorValueChanged<T>
    ? this as MySelectorValueChanged<T>
    : null;