How-to-create-a-Combobox-winthin-in-a-Stringgrid


            Title: How to create a Combobox winthin in a Stringgrid
Question: How to dynamically create a Combobox within a Cell of a StringGrid 
Answer:
You need a descendent of TStringgrid that properly reflects WM_COMMAND to 
embedded controls. The standard grid does not do it since it is not intended 
to play parent to other controls.
Additionaly simply declare a Set- and GetMethod to access the items of die combobox 
best regards
Boris Benjamin Wittfoth
unit BWControlStringGrid;
interface
uses
 Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
 Grids,stdctrls;
type
 TBWControlStringGrid = class(TStringGrid)
 private
 fComboBox:TCombobox;
 Procedure WMCommand( var msg: TWMCommand ); message WM_COMMAND;
 procedure DblClick;override;
 procedure Click;override;
 procedure RelocateComboBox;
 procedure HideCombobox;
 protected
 procedure KeyPress(var Key: Char); override;
 public
 Constructor Create(AOWner:TComponent);override;
 Destructor Destroy;override;
 published
 end;
procedure Register;
implementation
procedure Register;
begin
 RegisterComponents('hEaDRoOm', [TBWControlStringGrid]);
end;
procedure TBWControlStringGrid.WMCommand(var msg: TWMCommand);
begin
 If EditorMode and ( msg.Ctl = fComboBox.Handle ) Then
 inherited
 Else
 If msg.Ctl 0 Then
 msg.result :=
 SendMessage( msg.ctl, CN_COMMAND,
 TMessage(msg).wparam,
 TMessage(msg).lparam );
end;
procedure TBWControlStringGrid.KeyPress(var Key: Char);
begin
 if Key=#13 then
 RelocateComboBox
 else HideCombobox;
end;
procedure TBWControlStringGrid.DblClick;
begin
 inherited;
 RelocateComboBox;
end;
procedure TBWControlStringGrid.Click;
begin
 inherited;
 HideCombobox;
end;
procedure TBWControlStringGrid.RelocateComboBox;
begin
 fcombobox.boundsrect := CellRect( Selection.Left, Selection.Top);
 fcomboBox.Visible:=TRUE;
 fcombobox.setfocus;
end;
procedure TBWControlStringGrid.HideCombobox;
begin
 fcomboBox.Visible:=false;
end;
Constructor TBWControlStringGrid.Create(AOWner:TComponent);
begin
 inherited Create(Aowner);
 fComboBox:=TComboBox.Create(self);
 fComboBox.Parent:=self;
 fComboBox.Visible:=FALSE;
 Options:=Options-[goRangeSelect];
end;
Destructor TBWControlStringGrid.Destroy;
begin
 fComboBox.Destroy;
 inherited destroy;
end;
end.
VCL Delphi
