自动调整最合适的DBGrid的宽度

(*

--- english -------------------------------------------------------------------

This will change (reduce or extend) the width of column(s) so they all

fit in the Grid.

If aChangeAll = False then only the last col will be modified.

--- german --------------------------------------------------------------------

Anpassung (Vergr ßerung oder Verkleinerung) der Spaltenbreite(n).

Wenn aChangeAll = False, dann wird nur die letzte Spalte ver ändert.

*)

procedure ChangeColumnWidths(DBGrid: TDBGrid; aChangeAll: boolean);

var

 NewWidth,

 TotalColumnWidth,

 ColumnCount,

 GridClientWidth,

 StepWidth,

 i: integer;

begin

 ColumnCount := DBGrid.Columns.Count;

 if ColumnCount = 0 then Exit;

 // Ermitteln der momentanen Breite des Grids

 // look for the actual size of all columns

 TotalColumnWidth := 0;

 for i := 0 to ColumnCount-1 do

   TotalColumnWidth := TotalColumnWidth + DBGrid.Columns[i].Width;

 if dgColLines in DBGrid.Options then

   TotalColumnWidth := TotalColumnWidth + ColumnCount;

 // Ermitteln der max. Breite des Grids

 // What's the total Grid width?

 GridClientWidth := DBGrid.Width - GetSystemMetrics(SM_CXVSCROLL);

 if dgIndicator in DBGrid.Options then begin

   GridClientWidth := GridClientWidth - IndicatorWidth;

   if dgColLines in DBGrid.Options then

     Dec(GridClientWidth);

 end;

 if DBGrid.BorderStyle = bsSingle then begin

   if DBGrid.Ctl3D then // 2 * 2 Pixel

     GridClientWidth := GridClientWidth - 4

   else // 2 * 1 Pixel

     GridClientWidth := GridClientWidth - 2;

 end;

 // Neue Spaltenbreiten setzen: vergößern

 // change the width(s): extend size/width

 if TotalColumnWidth < GridClientWidth then begin

   StepWidth := (GridClientWidth - TotalColumnWidth) div ColumnCount;

   // Alle Spalten anpassen

   // for all columns

   if aChangeAll then begin

     for i := 0 to ColumnCount-1 do

       DBGrid.Columns[i].Width := DBGrid.Columns[i].Width + StepWidth;

   // Nur letzte Splate anpassen

   // only for the last one

   end else

     DBGrid.Columns[ColumnCount-1].Width := DBGrid.Columns[ColumnCount-1].Width + ColumnCount * StepWidth;

 end

 // Neue Spaltenbreiten setzen: verkleinern

 // change the width(s): reduce size/width

 else if TotalColumnWidth > GridClientWidth then begin

   StepWidth := (TotalColumnWidth - GridClientWidth) div ColumnCount;

   if (TotalColumnWidth - GridClientWidth) mod ColumnCount <> 0 then Inc(StepWidth);

   // Alle Spalten anpassen

   // for all columns

   if aChangeAll then begin

     for i := 0 to ColumnCount-1 do begin

       NewWidth := DBGrid.Columns[i].Width - StepWidth;

       if (NewWidth > 5) then DBGrid.Columns[i].Width := NewWidth;

     end;

   // Nur letzte Splate anpassen

   // only for the last one

   end else begin

     NewWidth := DBGrid.Columns[ColumnCount-1].Width - ColumnCount * StepWidth;

     if (NewWidth > 5) then DBGrid.Columns[ColumnCount-1].Width := NewWidth;

   end;

 end;

end;