Spread Windows Forms 18
Spread Windows Forms 18 Product Documentation / Developer's Guide / Cell Types / Understanding Additional Features of Cell Types / Creating a Custom Cell Type
In This Topic
    Creating a Custom Cell Type
    In This Topic

    You can implement your own types of cells by creating a subclass that inherits an existing cell type (that is, overriding each method in that class). The custom cell type class should be marked as serializable if the Clipboard will be used with it or if the export to Excel methods are used.

    or information on other features of cell types, refer to Understanding Additional Features of Cell Types.

    Using Code

    This example subclasses the check box cell type to illustrate the use of the methods.

    C#
    Copy Code 
    class myCkBox : FarPoint.Win.Spread.CellType.CheckBoxCellType
                {
                CheckBox ckbx = new CheckBox();
                
                public myCkBox()
                {
                }
                new event EventHandler EditingCanceled;
                new event EventHandler EditingStopped;
                
                public override void StartEditing(EventArgs e, bool selectAll, bool autoClipboard)
                {
                   return;
                }
                public override void CancelEditing()
                {
                   EditingCanceled(ckbx, EventArgs.Empty);
                   base.FireEditingCanceled();
                }
                public override bool StopEditing()
                {
                   if (EditingStopped != null)
                   {
                      EditingStopped(ckbx, EventArgs.Empty);
                      base.FireEditingStopped();
                      return true;
                   }
                   else
                   {
                      return false;
                   }
                }
                
                public override bool IsReservedKey(KeyEventArgs e)
                {
                   return base.IsReservedKey(e);
                }
                public override object IsReservedLocation(Graphics g, int x, int y, Rectangle r, FarPoint.Win.Spread.Appearance appr, object
                value, float zoom)
                {
                   return base.IsReservedLocation(g, x, y, r, appr, value, zoom);
                }
                public override Size GetPreferredSize(Graphics g, Size size, FarPoint.Win.Spread.Appearance appr, object value, float zoom)
                {
                   return base.GetPreferredSize(g, size, appr, value, zoom);
                }
                public override object Parse(string s)
                {
                   return base.Parse(s);
                }
                public override string Format(object o)
                {
                   return base.Format(o.ToString());
                }
                public override Control GetEditorControl(FarPoint.Win.Spread.Appearance appearance, float zoomFactor)
                {
                   return ckbx;
                }
                public override object GetEditorValue()
                {
                   return ckbx.CheckState;
                }
                public override void PaintCell(Graphics g, Rectangle r, FarPoint.Win.Spread.Appearance appr, object value, bool issel, bool
                islocked, float zoom)
                {
                   GetEditorValue();
                   if (ckbx.CheckState == CheckState.Checked)
                   {
                      ControlPaint.DrawCheckBox(g, r.X, r.Y, r.Width - 40, r.Height - 6, ButtonState.Checked);
                   }
                   else if (ckbx.CheckState == CheckState.Unchecked)
                   {
                     ControlPaint.DrawCheckBox(g, r.X, r.Y, r.Width - 40, r.Height - 6, ButtonState.Normal);
                   }
                }
                public override void SetEditorValue(object value)
                {
                   ckbx.CheckState = CheckState.Checked;
                }
                public override Cursor GetReservedCursor(object o)
                {
                   return base.GetReservedCursor(o);
                }
                }
                
                private void menuItem4_Click(object sender, System.EventArgs e)
                {
                   myCkBox ckbx = new myCkBox();
                   fpSpread1.ActiveSheet.Cells[0, 0].CellType = ckbx;
                }
    Visual Basic
    Copy Code 
    Public Class myCkBox
                Inherits FarPoint.Win.Spread.CellType.CheckBoxCellType
                
                Dim ckbx As New CheckBox()
                
                Sub New()
                
                End Sub
                
                Public Shadows Event EditingStopped(ByVal sender As Object, ByVal e As EventArgs)
                
                Public Shadows Event EditingCancelled(ByVal sender As Object, ByVal e As EventArgs)
                
                Public Overrides Sub StartEditing(ByVal e As EventArgs, ByVal selectAll As Boolean, ByVal autoClipboard As Boolean)
                   MyBase.StartEditing(e, selectAll, autoClipboard)
                End Sub
                
                Public Overrides Sub CancelEditing()
                   RaiseEvent EditingCancelled(ckbx, EventArgs.Empty)
                   MyBase.FireEditingCanceled()
                End Sub
                
                Public Overrides Function StopEditing() As Boolean
                   RaiseEvent EditingStopped(ckbx, EventArgs.Empty)
                   MyBase.FireEditingStopped()
                   Return True
                End Function
                
                Public Overrides Function IsReservedKey(ByVal e As KeyEventArgs) As Boolean
                   Return MyBase.IsReservedKey(e)
                End Function
                
                Public Overrides Function IsReservedLocation(ByVal g As Graphics, ByVal x As Integer, ByVal y As Integer, ByVal r As Rectangle,
                ByVal appr As FarPoint.Win.Spread.Appearance, ByVal value As Object, ByVal zoom As Single) As Object
                   Return MyBase.IsReservedLocation(g, x, y, r, appr, value, zoom)
                End Function
                
                Public Overrides Function GetPreferredSize(ByVal g As Graphics, ByVal s As Size, ByVal appr As FarPoint.Win.Spread.Appearance,
                ByVal value As Object, ByVal zoom As Single) As Size
                   Return MyBase.GetPreferredSize(g, s, appr, value, zoom)
                End Function
                
                Public Overrides Function Parse(ByVal s As String) As Object
                   Return MyBase.Parse(s)
                End Function
                
                Public Overrides Function Format(ByVal o As Object) As String
                   Return MyBase.Format(o)
                End Function
                
                Public Overrides Function GetEditorControl(ByVal appr As FarPoint.Win.Spread.Appearance, ByVal zoom As Single) As Control
                   Return ckbx
                End Function
                
                Public Overrides Function GetEditorValue() As Object
                   Return ckbx.CheckState
                End Function
                
                Public Overrides Sub PaintCell(ByVal g As Graphics, ByVal r As Rectangle, ByVal appr As FarPoint.Win.Spread.Appearance, ByVal
                Value As Object, ByVal issel As Boolean, ByVal islocked As Boolean, ByVal zoom As Single)
                   GetEditorValue()
                   If ckbx.CheckState = CheckState.Checked Then
                      ControlPaint.DrawCheckBox(g, r.X, r.Y, r.Width - 40, r.Height - 6, ButtonState.Checked)
                   ElseIf ckbx.CheckState = CheckState.Unchecked Then
                      ControlPaint.DrawCheckBox(g, r.X, r.Y, r.Width - 40, r.Height - 6, ButtonState.Normal)
                   End If
                End Sub
                
                Public Overrides Sub SetEditorValue(ByVal value As Object)
                   ckbx.CheckState = CheckState.Checked
                End Sub
                
                Public Overrides Function GetReservedCursor(ByVal o As Object) As Cursor
                   Return MyBase.GetReservedCursor(o)
                End Function
                End Class
                
                Private Sub MenuItem1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MenuItem1.Click
                   Dim ckbx As New myCkBox()
                   fpSpread1.ActiveSheet.Cells(0, 0).CellType = ckbx
                End Sub