using System.ComponentModel.DataAnnotations; namespace dy.net.dto { public class DouyinVideoPageRequestDto : PageRequestDto { // 3. 引用类型(string)如果允许为null,显式声明为 string? public string? Tag { get; set; } public string? Author { get; set; } public string? ViedoType { get; set; } // 4. 泛型集合(List)允许为null,声明为 List? public List? Dates { get; set; } } public class PageRequestDto { public int PageIndex { get; set; } public int PageSize { get; set; } = 10; } }