Checkbox-Transparent başlıklı checkbox

procedure EditWinIni;

type

TMyCheckBox = class(TCheckBox)

protected

procedure CNDrawItem(var Message: TWMDrawItem); message CN_DRAWITEM;

procedure CreateParams(var Params: TCreateParams); override;

procedure CreateWnd; override;

procedure SetButtonStyle;

end;

procedure TMyCheckBox.CNDrawItem(var Message: TWMDrawItem);

var

XCanvas: TCanvas;

XCaptionRect, XGlyphRect: TRect;

procedure xxDrawBitMap(ACanvas: TCanvas);

const xx_h = 13;xx_w = 13;

var  xxGlyph: TBitmap; xxX, xxY, xxStepY, xxStepX: integer;

begin

xxGlyph := TBitmap.Create;

try

xxGlyph.Handle := LoadBitmap(0, PChar(OBM_CHECKBOXES));

xxY := XGlyphRect.Top + (XGlyphRect.Bottom - XGlyphRect.Top - xx_h) div 2;

xxX := 2;

xxStepX := 0;

xxStepY := 0;

case State of

cbChecked: xxStepX := xxStepX + xx_w;

cbGrayed:  xxStepX := xxStepX + xx_w * 3;

end;

ACanvas.CopyRect(Rect(xxX, xxY, xxX + xx_w,  xxY + xx_h), xxGlyph.Canvas,

Rect(xxStepX, xxStepY, xx_w + xxStepX, xx_h + xxStepY));

finally

xxGlyph.Free;

end;end;

procedure xxDrawCaption;

var

xXFormat: longint;

begin

xXFormat := DT_VCENTER + DT_SINGLELINE + DT_LEFT;

xXFormat := DrawTextBiDiModeFlags(xXFormat);

DrawText(Message.DrawItemStruct.hDC, PChar(Caption), length(Caption), XCaptionRect, xXFormat);

end;

begin

XGlyphRect := Message.DrawItemStruct.rcItem;

XGlyphRect.Right := 20;

XCaptionRect := Message.DrawItemStruct.rcItem;

XCaptionRect.Left := XGlyphRect.Right;

XCanvas := TCanvas.Create;

try

XCanvas.Handle := Message.DrawItemStruct.hDC;

XCanvas.Brush.Style := bsClear;

xxDrawBitMap(XCanvas);

xxDrawCaption;

finally

XCanvas.Free;

end; end;

procedure TMyCheckBox.CreateParams(var Params: TCreateParams);

begin

inherited CreateParams(Params);

Params.ExStyle := Params.ExStyle or WS_EX_Transparent;

end;

procedure TMyCheckBox.CreateWnd;

begin

inherited CreateWnd;

SetButtonStyle;

end;

procedure TMyCheckBox.SetButtonStyle;

const

BS_MASK = $000F;

var

Style: Word;

begin

if HandleAllocated then

begin

Style := BS_CHECKBOX or BS_OWNERDRAW;

if GetWindowLong(Handle, GWL_STYLE) and BS_MASK <> Style then

SendMessage(Handle, BM_SETSTYLE, Style, 1);

end;end;