DBGrid selber zeichnen

[Dietmar Maier]

Hallo alle zusammen,

anbei meinen Source zum selber zeichnen des Gridinhaltes mit dem Ereigniss OnDrawColumnCell.

Das Zeichnen einer gesamten Zeile (dgRowSelect, dgAlwaysShowSelection, dgMultiSelect), welches im Normalfall vom Grid erledigt wird ist bei Verwendung von OnDrawColumnCell mit dem normalen Grid nicht möglich, da die benötigten Propertys dazu private oder protected sind.

Deswegen habe ich die Komponente TdmDBGrid von TDBGrid abgeleitet und um die benötigten Propertys erweitert.

type
TdmDBGrid = class(TDBGrid)
protected
iDrawCol : Longint;
iDrawRow : Longint;
procedure DrawCell(ACol, ARow: Longint; ARect: TRect; AState: TGridDrawState); override;
public
constructor Create(AOwner: TComponent); override;
property Col;
property Row;
property DrawCol : Longint read iDrawCol;
property DrawRow : Longint read iDrawRow;
end;

constructor TdmDBGrid.Create(AOwner: TComponent);
begin
iDrawCol := -1;
iDrawRow := -1;

inherited;
end;
//------------------------------------------------------------------------------

procedure TdmDBGrid.DrawCell(ACol, ARow: Integer; ARect: TRect; AState: TGridDrawState);
begin
iDrawCol := ACol;
iDrawRow := ARow;

inherited;
end;
//------------------------------------------------------------------------------

procedure GridsDrawColumnCell(Sender: TObject;
const Rect: TRect; DataCol: Integer; Column: TColumn;
State: TGridDrawState; Canvas : TCanvas;
FontColor, BrushColor : TColor);
var
sText : String;
iTextWidth : Integer;
iOffset : Integer;
Index: Integer;
begin
sText := '';
if Assigned(Column.Field) then
begin
sText := Column.Field.DisplayText;
end;

iTextWidth := Canvas.TextWidth(sText);
iOffset := 2;

case Column.Alignment of
taCenter : iOffset := (Rect.Right - Rect.Left - iTextWidth) div 2;
taRightJustify : iOffset := (Rect.Right - Rect.Left - iTextWidth) - 2;
end;

if (State = [gdFixed]) then
begin
BrushColor := TDBGrid(Sender).FixedColor;
end;

// Farbänderung im Grid ermöglichen
if (Column.Color <> Column.Grid.Brush.Color) then
begin
BrushColor := Column.Color;
end;

if (State = [gdSelected, gdFocused]) then
begin
FontColor := clWhite;
BrushColor := clNavy;
end;

if (Column.Grid is TdmDBGrid) then
begin
if (TdmDBGrid(Column.Grid).DrawRow = TdmDBGrid(Column.Grid).Row) and
(((dgRowSelect in TDBGrid(Column.Grid).Options) and (TDBGrid(Column.Grid).Focused)) or
(dgAlwaysShowSelection in TDBGrid(Column.Grid).Options)) then
begin
FontColor := clWhite;
BrushColor := clNavy;
end;
end;

if TDBGrid(Column.Grid).SelectedRows.CurrentRowSelect ed then
begin
FontColor := clWhite;
BrushColor := clNavy;
end;

Canvas.Font.Color := FontColor;
Canvas.Brush.Color := BrushColor;
Canvas.TextRect(Rect, Rect.Left + iOffset, Rect.Top + 2, sText);
end;
//------------------------------------------------------------------------------

procedure GridsDrawColumnCell_Ext(Sender: TObject;
const Rect: TRect; DataCol: Integer; Column: TColumn;
State: TGridDrawState; Canvas : TCanvas;
FontColor, BrushColor, ReadOnlyColor, ToggleColor : TColor);
var
iRecNo : Longint;
begin
if Assigned(Column.Field) then
begin
if (ToggleColor <> clNone) then
begin
iRecNo := Column.Field.DataSet.RecNo;

{$IFDEF DB_ORACLE}
if (iRecNo < 1) then
begin
if Assigned(Column.Field.DataSet.FindField('ROWNUM')) then
begin
iRecNo := Column.Field.DataSet.FieldByName('ROWNUM').AsInteg er;
end;
end;
{$ENDIF}

if (iRecNo mod 2 = 0) then
begin
BrushColor := ToggleColor;
end;
end;

if (ReadOnlyColor <> clNone) then
begin
if (Column.Field.ReadOnly) or (Column.ReadOnly) then
begin
BrushColor := ReadOnlyColor;

if (FontColor = clWindowText) then
begin
FontColor := clGrayText;
end;
end;
end;
end;

GridsDrawColumnCell(Sender, Rect, DataCol, Column, State,
TDBGrid(Sender).Canvas, FontColor, BrushColor);
end;
//------------------------------------------------------------------------------

Verwendet wird es z.B.:

procedure TmeinFormular.dmDBGrid1DrawColumnCell(Sender: TObject;
const Rect: TRect; DataCol: Integer; Column: TColumn; State: TGridDrawState);
var
FontColor : TColor;
BrushColor : TColor;
begin
FontColor := TDBGrid(Sender).Font.Color;
BrushColor := TDBGrid(Sender).Color;

if Assigned(Column.Field.DataSet.FindField('Droge_Che mikalie')) then
begin
if (Column.Field.DataSet.FieldByName('Droge_Chemikali e').AsString = 'D') then
begin
BrushColor := cclDROGE;
end;
end;

if Assigned(Column.Field.DataSet.FindField('BTM')) then
begin
if (Column.Field.DataSet.FieldByName('BTM').AsString = 'B') then
begin
BrushColor := cclBETEUBUNGSMITTEL;
end;
end;

if Assigned(Column.Field.DataSet.FindField('Vertriebs status')) then
begin
if (Column.Field.DataSet.FieldByName('Vertriebsstatus ').AsString = 'AV') then
begin
BrushColor := cclVERTRIEBSSTATUS;
end;
end;

GridsDrawColumnCell(Sender, Rect, DataCol, Column, State,
TDBGrid(Sender).Canvas, FontColor, BrushColor);
end;
//------------------------------------------------------------------------------

mfg. Dietmar Maier
(maier-soft)