Question

I have a DataGrid containing a small table. Until now, I had a double click handler on this grid which iterated over all rows to find the selected one:

DataTable table = (DataTable)this.dataGrid.DataSource;
int selectedRow = -1;
for (int i=0; i<table.Rows.Count; i++)
  if (this.dataGrid.IsSelected(i))
    selectedRow = i;
    break;
  }
if ( selectedRow != -1 ) {
  DataRow row = table.Rows[selectedRow];
  // More code ...
}

Problem: When the user clicks on a column header and sort the table, table.Rows does not return the right rows. It still contains the unsorted rows.

How can I get the right column?

Edit 1: I have a System.Windows.Forms.DataGrid, not a DataGridView. I don’t know the difference, because I don’t know .Net very much. Can I simply replace DataGrid with DataGridView?

Answer 1

DataGrid (Windows)

Try DataGrid.GetSelectedDataRows below, where MyBase is the name of your DataGrid.

    Public Function GetSelectedDataRows() As DataRow()
        Dim oSelectedRows As New ArrayList
        Dim oDataTable As DataTable = DirectCast(MyBase.DataSource, DataTable)
        For i As Integer = 0 To oDataTable.Rows.Count - 1
            If MyBase.IsSelected(i) Then
                oSelectedRows.Add(oDataTable.DefaultView(i).Row)
            End If
        Next
        Return DirectCast(oSelectedRows.ToArray(GetType(DataRow)), DataRow())
    End Function

DataGridView

Use the SelectedRows property. It returns the collection of DataGridViewRow objects. Since you know you are binding a DataTable, the DataGridViewRow.DataBoundItem property will be a DataRow. Check the above object help topics for examples.

References

• Differences Between the Windows Forms DataGridView and DataGrid Controls at http://msdn.microsoft.com/en-us/library/ms171628.aspx

• DataGridView Class at
  http://msdn.microsoft.com/en-us/library/system.windows.forms.datagridview.aspx

• DataGrid Class at http://msdn.microsoft.com/en-us/library/system.windows.forms.datagrid.aspx

Excerpts

The DataGrid control is retained for
backward compatibility and for special
needs. For nearly all purposes, you
should use the DataGridView control.
The only feature that is available in
the DataGrid control that is not
available in the DataGridView control
is the hierarchical display of
information from two related tables in
a single control. You must use two
DataGridView controls to display
information from two tables that are
in a master/detail relationship.