How to calculate the "Left" Property to center a Text in a DBGrid Cell?

Question

Continuing with the project started in:

How to auto fit/scale DBGrid's (or other similar) columns widths according to its contents?

How to calculate the "Left" Property to center a Text in a DBGrid Cell?

When we call OnDrawColumnCell and use the Canvas to write a text in replacement of the default draw of the grid, how may we calculate the position of the text when we want to center it on the cell?

Answer 1

Don't. Paint the text with DrawText/DrawTextEx and specify DT_CENTER in the format parameter. See also Draw text multiline in the centre of a rect.

Or if you want or need to calculate it yourself:

procedure DrawCenteredText(Canvas: TCanvas; const S: String; R: TRect);
var
  Left: Integer;
begin
  Left := R.Left + (R.Right - R.Left - Canvas.TextWidth(S)) div 2;

Answer 2

An easier way with more possibilities will be:

Canvas.TextRect(Rect,s,[tfCenter,tfVerticalCenter,tfSingleLine]);