获取筛选表的选定索引

Question

我有绑定到视图模型上datatable的datagrid，我有用于过滤相关行的filter按钮。我想在筛选完表格后获取选定的索引

<DataGrid    
   DataContext="{Binding MyVM, Source={StaticResource Locator}}"                                  
   CanUserAddRows="False"
   IsReadOnly="True"
   SelectionUnit="FullRow"
   AutoGenerateColumns="False"
   SelectedIndex="{Binding SelectedIndexDDG}"
   SelectedValue="{Binding SelectionValueDDG}" 
   ItemsSource="{Binding JobsViewDT, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}">

ViewModel：

 void FilterBtnCommand()
 {   
    JobsViewDT.DefaultView.RowFilter = $"DateTime >= {DateTime.Now} AND DateTime <= {DateTime.Now.AddDays(5)}";
 }
 ...
 public DataTable JobsViewDT
 {
     get{return jobsViewDT;}
        set
        {
            Set(() => JobsViewDT, ref jobsViewDT, value);
            RaisePropertyChanged("JobsViewDT");
        }
 }

  

但是在表被过滤后，我选择了某行，它将所选的行索引视为原始表，而不是已过滤的表。