# .NET MVC 日期選擇器衍生 ---- ###### tags: `.NET` `MVC` 前端code ```csharp= <div class="form-group input-group-sm"> @Html.LabelFor(m => m.TestDate) @Html.TextBoxFor(m => m.TestDate, new { @class = "form-control datepicker", placeholder = "Enter Drop-off date here..." }) @Html.ValidationMessageFor(m => m.TestDate) </div> ``` ```javascript= @section Scripts{ // 引入jQ $('.datepicker').datetimepicker({ format: 'YYYY/MM/DD HH:mm', }); } ``` 後端接值 ViewModel 分成兩種 ```csharp= [Display(Name = "日期")] [Required] [DataType(DataType.DateTime)] [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:YYYY/MM/DD HH:mm}")] public DateTime TestDate { get; set; } ``` 多出`?`的 ```csharp= [Display(Name = "日期")] [Required] [DataType(DataType.DateTime)] [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:YYYY/MM/DD HH:mm}")] public DateTime? TestDate { get; set; } ``` Controller寫的方式不同 ```csharp= // 不能加? DateTime time = model.TestDate; // 加上?後 DateTime time = model.TestDate.GetValueOrDefault(); var time2 = model.TestDate.GetValueOrDefault(); return Content(time.ToString()); ```