After the Windows Forms DataGrid is connected to a database, you can monitor which cell the user clicked.

To detect when the user of the DataGrid selects a different cell

• In the CurrentCellChanged event handler, write code to respond appropriately.
  ' Visual Basic
  Private Sub myDataGrid_CurrentCellChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles myDataGrid.CurrentCellChanged
     MessageBox.Show("Col is " & myDataGrid.CurrentCell.ColumnNumber _
        & ", Row is " & myDataGrid.CurrentCell.RowNumber _
        & ", Value is " & myDataGrid.Item(myDataGrid.CurrentCell))
  End Sub
  
  // C#
  private void myDataGrid_CurrentCellChanged(object sender, 
  System.EventArgs e)
  {
     MessageBox.Show ("Col is " + myDataGrid.CurrentCell.ColumnNumber
        + ", Row is " + myDataGrid.CurrentCell.RowNumber 
        + ", Value is " + myDataGrid[myDataGrid.CurrentCell] );
  }

  Visual C# Note   Be sure that the necessary code to enable the event handler is present. In this case, it would be similar to the following:

  this.myDataGrid.CurrentCellChanged += new

  System.EventHandler(this.myDataGrid_CurrentCellChanged);

To determine which part of the DataGrid the user clicked

• Call the HitTest method in an appropriate event handler, such as for the MouseDown or Click event.

  The HitTest method returns a DataGrid.HitTestInfo object that contains the row and column of a clicked area.

  ' Visual Basic
  Private Sub myDataGrid_MouseDown(ByVal sender As Object, _
  ByVal e As MouseEventArgs) Handles myDataGrid.MouseDown
     Dim myGrid As DataGrid = CType(sender, DataGrid)
     Dim hti As System.Windows.Forms.DataGrid.HitTestInfo
     hti = myGrid.HitTest(e.X, e.Y)
     Dim message As String = "You clicked "
  
     Select Case hti.Type
        Case System.Windows.Forms.DataGrid.HitTestType.None
           message &= "the background."
        Case System.Windows.Forms.DataGrid.HitTestType.Cell
           message &= "cell at row " & hti.Row & ", col " & hti.Column
        Case System.Windows.Forms.DataGrid.HitTestType.ColumnHeader
           message &= "the column header for column " & hti.Column
        Case System.Windows.Forms.DataGrid.HitTestType.RowHeader
           message &= "the row header for row " & hti.Row
        Case System.Windows.Forms.DataGrid.HitTestType.ColumnResize
           message &= "the column resizer for column " & hti.Column
        Case System.Windows.Forms.DataGrid.HitTestType.RowResize
           message &= "the row resizer for row " & hti.Row
        Case System.Windows.Forms.DataGrid.HitTestType.Caption
           message &= "the caption"
        Case System.Windows.Forms.DataGrid.HitTestType.ParentRows
           message &= "the parent row"
     End Select
  
     Console.WriteLine(message)
  End Sub
  
  // C#
  private void myDataGrid_MouseDown(object sender, 
  System.Windows.Forms.MouseEventArgs e)
  {
     DataGrid myGrid = (DataGrid) sender;
     System.Windows.Forms.DataGrid.HitTestInfo hti;
     hti = myGrid.HitTest(e.X, e.Y);
     string message = "You clicked ";
  
     switch (hti.Type) 
     {
        case System.Windows.Forms.DataGrid.HitTestType.None :
           message += "the background.";
           break;
        case System.Windows.Forms.DataGrid.HitTestType.Cell :
           message += "cell at row " + hti.Row + ", col " + hti.Column;
           break;
        case System.Windows.Forms.DataGrid.HitTestType.ColumnHeader :
           message += "the column header for column " + hti.Column;
           break;
        case System.Windows.Forms.DataGrid.HitTestType.RowHeader :
           message += "the row header for row " + hti.Row;
           break;
        case System.Windows.Forms.DataGrid.HitTestType.ColumnResize :
           message += "the column resizer for column " + hti.Column;
           break;
        case System.Windows.Forms.DataGrid.HitTestType.RowResize :
           message += "the row resizer for row " + hti.Row;
           break;
        case System.Windows.Forms.DataGrid.HitTestType.Caption :
           message += "the caption";
           break;
        case System.Windows.Forms.DataGrid.HitTestType.ParentRows :
           message += "the parent row";
           break;
        }
  
        Console.WriteLine(message);
  }

  Visual C# Note   Be sure that the necessary code to enable the event handler is present. In this case, it would be similar to the following:

  this.myDataGrid.MouseDown += new
     System.Windows.Forms.MouseEventHandler
     (this.myDataGrid_MouseDown);

See Also

DataGrid Control (Windows Forms) | Changing Displayed Data at Run Time in the Windows Forms DataGrid Control