xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk"
添加System.Windows.Controls.Data.Toolkit 引用
<sdk:DatePicker x:Name="SDate" Height="25" IsTodayHighlighted="True" SelectedDate="{Binding sdatetime,Mode=TwoWay,ValidatesOnDataErrors=True, ValidatesOnExceptions=True}" />