How to draw a "not" colored text?
I'm looking for a way to draw text with inverted colors.
For shapes, we have TPenMode
that can b开发者_JAVA技巧e set to pmNot
, but we can't do this for text. How can I do this instead?
This does it:
procedure DrawTextNOT(const hDC: HDC; const Font: TFont; const Text: string; const X, Y: integer);
begin
with TBitmap.Create do
try
Canvas.Font.Assign(Font);
with Canvas.TextExtent(Text) do
SetSize(cx, cy);
Canvas.Brush.Color := clBlack;
Canvas.FillRect(Rect(0, 0, Width, Height));
Canvas.Font.Color := clWhite;
Canvas.TextOut(0, 0, Text);
BitBlt(hDC, X, Y, Width, Height, Canvas.Handle, 0, 0, SRCINVERT);
finally
Free;
end;
end;
Example:
procedure TForm1.FormClick(Sender: TObject);
begin
Canvas.Brush.Color := clRed;
Canvas.FillRect(ClientRect);
DrawTextNOT(Canvas.Handle, Canvas.Font, 'This is a test.', 20, 100);
// DrawTextNOT(Canvas.Handle, Canvas.Font, 'This is a test.', 20, 100);
end;
You probably also want to disable ClearType. To do that, I refer you to a previous SO question.
GDI text isn't drawn with a pen. Have you considered drawing the text to a temporary bitmap, and copying with BitBlt
? There's probably a combination of the dwRop
raster operations that can get the effect you're looking for.
精彩评论