Mega Code Archive
Drawing in TMemo
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Title: Drawing in TMemo
Question: How can I draw something on the TMemo?
Answer:
For drawing on TMemo surface we should create our component derived from TMemo and override its drawing. Something like this:
type
TMyMemo = class(TMemo)
protected
procedure WMPaint(var Message: TWMPaint); message WM_PAINT;
end;
And insert realisation of this procedure:
procedure TMyMemo.WMPaint(var Message: TWMPaint);
var
MCanvas: TControlCanvas;
DrawBounds : TRect;
Begin
inherited;
MCanvas:=TControlCanvas.Create;
DrawBounds := ClientRect; // Work with temporary TRect record.
Try
MCanvas.Control:=Self;
With MCanvas do
Begin
Brush.Color := clBtnFace;
FrameRect( DrawBounds );
InflateRect( DrawBounds, -1, -1);
FrameRect( DrawBounds );
FillRect ( DrawBounds );
MoveTo ( 33, 0 );
Brush.Color := clWhite;
LineTo ( 33, ClientHeight );
PaintImages;
end;
finally
MCanvas.Free;
End;
end;
The PaintImages procedure paint images on the Memo's canvas.
procedure TMyMemo.PaintImages;
var
MCanvas: TControlCanvas;
DrawBounds : TRect;
i, j : Integer;
OriginalRegion : HRGN;
ControlDC : HDC;
begin
MCanvas:=TControlCanvas.Create;
DrawBounds := ClientRect; // Work with temporary TRect record.
try
MCanvas.Control:=Self;
ControlDC := GetDC ( Handle );
MCanvas.Draw(0, 1, Application.Icon);
finally
MCanvas.Free;
end;
end;
Now you have your custom drawing memo.
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