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

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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 DataGrid.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