绑定在WPF Datagrid第二行标题中不起作用

Question

My Xaml-

 <Grid>
        <DataGrid Name="DataGrid" AutoGenerateColumns="False">
            <DataGrid.RowHeaderTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal" VerticalAlignment="Center" HorizontalAlignment="Center">
                        <TextBlock Text="19" />
                        <TextBlock Text="{Binding Path=Items.Year, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=DataGridRowHeader}}" Foreground="#9493CF" FontSize="16" />                        
                    </StackPanel>
                </DataTemplate>
            </DataGrid.RowHeaderTemplate>
            <DataGrid.Columns>                
                <DataGridTextColumn Header="Name" Binding="{Binding Path=Name}" />
                <DataGridTextColumn Header="Course" Binding="{Binding Path=Course}" />
            </DataGrid.Columns>        
        </DataGrid>
    </Grid>

in C#

  var itemList = new List<Items>();

  itemList.Add(new Items { Year = 22, Course = "B.SC", Name = "Jegadees" });
  itemList.Add(new Items { Year = 23, Course = "M.SC", Name = "Arun" });
  itemList.Add(new Items { Year = 55, Course = "B.Tech", Name = "Kanaga" });

  DataGrid.ItemsSource = itemList;

Item Collection -

 public class Items
    {        
        public string Name { get; set; }
        public string Course { get; set; }
        public int Year { get; set; }
    }

Answer 1

The ancestor with a DataContext of Item is the DataGridRow of the corosponding DataGridRowHeader

 <TextBlock Text="{Binding Path=DataContext.Year, 
                           RelativeSource={RelativeSource Mode=FindAncestor, 
                                            AncestorType=DataGridRow}}" /> 

Answer 2

With this piece of code RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=DataGridRowHeader}}" , you are travelling upto Visual Tree till you find first DataGridRowHeader .

Issue is in your Path - Path=Items.Year .

It will search for property Items in DataGridRowHeader which obviously it doesn't have.

You need to change Path to like this DataContext.Year because DataContext will get you actual object it's binded to ie an instance of Items class and then bind to its property Year in that instance.

So correct binding would be like this:

<TextBlock Text="{Binding Path=DataContext.Year,
                 RelativeSource={RelativeSource Mode=FindAncestor, 
                                    AncestorType=DataGridRowHeader}/>