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How to: Respond to Clicks in the Windows Forms DataGrid Control

NoteNote

The DataGridView control replaces and adds functionality to the DataGrid control; however, the DataGrid control is retained for both backward compatibility and future use, if you choose. For more information, see Differences Between the Windows Forms DataGridView and DataGrid Controls.

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.

    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
    
    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#) Place the following code in the form's constructor to register the event handler.

    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 HitTestInfo object that contains the row and column of a clicked area.

    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
    
    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#) Place the following code in the form's constructor to register the event handler.

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

See Also

Tasks

How to: Change Displayed Data at Run Time in the Windows Forms DataGrid Control

Other Resources

DataGrid Control (Windows Forms)