The bidirectional binding requires “Path” or “XPath” exception

Question

Hi

exception occurs when I leave a cell in my datagrid - but I didn't know where to find the error

<DataGrid ItemsSource="{Binding}" ...


<DataGrid.Columns>
                <DataGridTextColumn Width="40" Header="ID" Binding="{Binding ID}" >
                    <DataGridTextColumn.ElementStyle>
                        <Style TargetType="TextBlock">
                            <Setter Property="HorizontalAlignment" Value="Center" />
                        </Style>
                    </DataGridTextColumn.ElementStyle>
                </DataGridTextColumn>

                <DataGridTextColumn Width="250" Header="Name" Binding="{Binding Name}" >
                    <DataGridTextColumn.ElementStyle>
                        <Style TargetType="TextBlock">
                            <Setter Property="HorizontalAlignment" Value="Center" />
                        </Style>
                    </DataGridTextColumn.ElementStyle>
                </DataGridTextColumn>

My xaml looks like this ... and this is code behind

  InitializeComponent();
    dGrid.DataContext = DT.Datatable;

Any Idea?

Answer 1

I used your code in xmal and the background code uses the following code . Exception does not occur when I leave a cell in my datagrid. Did I do something less or is it different from yours? Please show me more relevant steps and codes to reproduce and analyze the problem.
The code of xaml is as follows:

<Grid>  
        <DataGrid x:Name="dGrid" ItemsSource="{Binding}" AutoGenerateColumns="False"  >  
            <DataGrid.Columns>  
                <DataGridTextColumn Header="ID" Width="80" Binding="{Binding ID}"  >  
                    <DataGridTextColumn.ElementStyle>  
                        <Style TargetType="TextBlock">  
                            <Setter Property="HorizontalAlignment" Value="Center" />  
                        </Style>  
                    </DataGridTextColumn.ElementStyle>  
                </DataGridTextColumn>  
                <DataGridTextColumn Header="Name" Width="80" Binding="{Binding Name}">  
                    <DataGridTextColumn.ElementStyle>  
                        <Style TargetType="TextBlock">  
                            <Setter Property="HorizontalAlignment" Value="Center" />  
                        </Style>  
                    </DataGridTextColumn.ElementStyle>  
                </DataGridTextColumn>  
            </DataGrid.Columns>  
        </DataGrid>  
  </Grid>  

The code of xaml.cs is as follows:

using System.Data;  
using System.Windows;  
namespace BidirectionalBindingException  
{  
  public partial class MainWindow : Window  
  {   
    public MainWindow()  
    {  
      InitializeComponent();  
      dGrid.DataContext = GetDummyData();  
    }  
    private static DataTable GetDummyData()  
    {  
      DataTable dt = new DataTable();  
      DataColumn ID = new DataColumn("ID", typeof(int));  
      dt.Columns.Add(ID);  
      dt.Columns.Add("Name", typeof(string));  
      dt.PrimaryKey = new DataColumn[] { ID };  
      dt.Rows.Add(1, "Name1");  
      dt.Rows.Add(2, "Name2");  
      return dt;  
    }  
  }  
}  

The result is shown in the figure:

Answer 2

Aaarg - I just wanted to post more - then the error blinks in my eyes :))

Binding line in column 3

<DataGridTextColumn Width="250" Header="Visual" Binding="{Binding VS}" >

DT.Columns.Add("Vs", typeof(string));

Mistyping Name

thanks for your help