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

Note
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)