Заголовок в DBGrid

Решение:

unit bdbgrid;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, Grids,
  DBGrids, Math;

type
  TOnDrawTitleEvent = procedure(ACol: integer; ARect: TRect;
                                var TitleText: string) of object;

  TBitDBGrid = class(TDBGrid)
  private
    FBitmapBrowse: TBitmap;
    FBitmapEdit: TBitmap;
    FBitmapInsert: TBitmap;
    FBitmapFill: TBitmap;
    FRealTitleFont: TFont;
    FOnDrawTitle: TOnDrawTitleEvent;
    FResizeFlag: boolean;
    procedure SetRealTitleFont(Value : TFont);
    procedure UpdateTitlesHeight;
  protected
    procedure DrawCell(ACol, ARow: Longint; ARect: TRect;
                       AState: TGridDrawState); override;
    procedure MouseDown(Button: TMouseButton; Shift: TShiftState;
                        X, Y: Integer); override;
    procedure MouseUp(Button: TMouseButton; Shift: TShiftState;
                      X, Y: Integer); override;
  public
    constructor Create(AOwner : TComponent);override;
    destructor Destroy; override;
  published
    property OnDrawTitle : TOnDrawTitleEvent read FOnDrawTitle write FOnDrawTitle;
    property RealTitleFont : TFont read FRealTitleFont write SetRealTitleFont;
end;

procedure Register;

implementation

var
  DrawBitmap: TBitmap;

function Max(X, Y: Integer): Integer;
begin
  Result := Y;
  if X > Y then Result := X;
end;

procedure WriteText(ACanvas: TCanvas; ARect: TRect; DX, DY: Integer;
                    const Text: string; Alignment: TAlignment);
const
  AlignFlags: array [TAlignment] of Integer =
              (DT_LEFT or DT_WORDBREAK or DT_EXPANDTABS or DT_NOPREFIX,
               DT_RIGHT or DT_WORDBREAK or DT_EXPANDTABS or DT_NOPREFIX,
               DT_CENTER or DT_WORDBREAK or DT_EXPANDTABS or DT_NOPREFIX);
var
  B, R: TRect;

begin
  with DrawBitmap, ARect do begin
    Width := Max(Width, Right - Left);
    Height := Max(Height, Bottom - Top);
    R := Rect(DX, DY, Right - Left - 1, Bottom - Top - 1);
    B := Rect(0, 0, Right - Left, Bottom - Top);
  end;
  with DrawBitmap.Canvas do begin
    DrawBitmap.Canvas.CopyRect(B, ACanvas, ARect);
    Font := ACanvas.Font;
    Font.Color := ACanvas.Font.Color;
    Brush := ACanvas.Brush;
    SetBkMode(Handle, TRANSPARENT);
    DrawText(Handle, PChar(Text), Length(Text), R, AlignFlags[Alignment]);
  end;
  ACanvas.CopyRect(ARect, DrawBitmap.Canvas, B);
end;

constructor TBitDBGrid.Create(AOwner: TComponent);
begin
  inherited Create(Aowner);
  FRealTitleFont := TFont.Create;
  FResizeFlag := false;
end;

destructor TBitDBGrid.Destroy;
begin
  FRealTitleFont.Free;
  inherited Destroy;
end;

procedure TBitDBGrid.UpdateTitlesHeight;
var
  Loop: integer;
  MaxTextHeight: integer;
  RRect: TRect;
begin
  MaxTextHeight := 0;
  for loop := 0 to Columns.Count - 1 do begin
    RRect := CellRect(0, 0);
    RRect.Right := Columns[Loop].Width;
    RRect.Left := 0;
    Canvas.Font := RealTitleFont;
    MaxTextHeight := Max(MaxTextHeight, DrawText(Canvas.Handle,
                         PChar(Columns[Loop].Title.Caption),
                         Length(Columns[Loop].Title.Caption), RRect,
                         DT_CALCRECT + DT_WORDBREAK));
  end;
  if TitleFont.Height <> - MaxTextHeight then TitleFont.Height := - MaxTextHeight;
end;

procedure TBitDBGrid.MouseDown(Button: TMouseButton; Shift: TShiftState;
                               X, Y: Integer);
begin
  if MouseCoord(X, Y).Y = 0 then FResizeFlag := True;
  inherited MouseDown(Button, Shift, X, Y);
end;

procedure TBitDBGrid.MouseUp(Button: TMouseButton; Shift: TShiftState;
                             X, Y: Integer);
begin
  inherited MouseUp(Button, Shift, X, Y);
  if FResizeFlag then begin
    FResizeFlag := False;
    UpdateTitlesHeight;
  end;
end;

procedure TBitDBGrid.DrawCell(ACol, ARow: Longint; ARect: TRect;
                              AState: TGridDrawState);
var
  TitleText: string;
  Al: TAlignment;
begin
  if not ((gdFixed in AState) and ((ARow = 0) and (dgTitles in Options)
      and (ACol <> 0))) then inherited DrawCell(ACol, ARow, ARect, AState)
  else begin
    if DefaultDrawing then begin
      DrawEdge(Canvas.Handle, ARect, BDR_RAISEDINNER, BF_BOTTOMLEFT);
      DrawEdge(Canvas.Handle, ARect, BDR_RAISEDINNER, BF_TOPRIGHT);
      InflateRect(ARect, -1, -1);
      Canvas.Brush.Color := FixedColor;
      Canvas.FillRect(ARect);
    end;
    TitleText := Columns[ACol - 1].Title.Caption;
    if Assigned(OnDrawTitle) then OnDrawTitle(ACol, ARect, TitleText);
    if DefaultDrawing and (TitleText <> '') then begin
      Canvas.Brush.Style := bsClear;
      Canvas.Font := RealTitleFont;
      if ACol > 0 then Al := Columns[ACol - 1].Title.Alignment
      else Al := Columns[0].Title.DefaultAlignment;
      WriteText(Canvas, ARect, 2, 2, TitleText, Al);
    end;
  end;
end;

procedure TBitDBGrid.SetRealTitleFont(Value: TFont);
begin
  FRealTitleFont.Assign(Value);
  Repaint;
end;

procedure Register;
begin
  RegisterComponents('Andre VCL', [TBitDBGrid]);
end;

initialization
  DrawBitmap := TBitmap.Create;

finalization
  DrawBitmap.Free;

end.