Question

编辑： 我想在TJvDBGrid（Project＆＃39; TDBGrid的Jedi后代）上绘制一个垂直居中的TIcon图形和Text。我试图禁用JvDBGrid的DefaultDrawing方法并覆盖它，但我只能用黑色填充单元格（我认为我的代码不完整以进行覆盖）。

现在我succeeded在单元格上绘制图标，文本与默认绘图保持一致。我如何将图标（垂直和水平）和文本（只是垂直）居中，如this？

这是我的代码：

procedure TFrmXXX.JvDBGridXXXDrawColumnCell(Sender: TObject; const Rect: TRect; DataCol: Integer; Column: TColumn; State: TGridDrawState);
var
  Icon: TIcon;
  fixRect: TRect;
  imgWidth: Integer;
begin
  fixRect := Rect;

  if Column.Index = 0  then //always the first one
  begin
    Icon := GetIcon; //Returns TIcon object
    try
      imgWidth := (Rect.Bottom - Rect.Top);
      fixRect.Right := Rect.Left + imgWidth;
      (Sender as TJvDBGrid).Canvas.StretchDraw(fixRect, Icon);
    finally
      Icon.Free;
    end;
    fixRect := Rect;
    fixRect.Left := fixRect.Left + imgWidth;
  end;

  (Sender as TJvDBGrid).DefaultDrawColumnCell(fixRect, DataCol, Column, State);
end;

Answer 1

经过多次测试，我找到了一个在互联网上合并不同教程的解决方案。在DrawColumnCell事件中，我写了这样的东西：

Canvas.FillRect(Rect); //Fill the cell using current brush.

在每个特定的列案例中，我使用了以下方法之一：

Canvas.Draw((Rect.Right - Rect.Left - Icon.Width) div 2 + Rect.Left, (Rect.Bottom - Rect.Top - Icon.Height) div 2 + Rect.Top, Icon); //Draw the graphic centered on cell

Canvas.DrawText(Canvas.Handle, PChar(Column.Field.DisplayText), Length(Column.Field.DisplayText), Rect, DT_VCENTER or DT_CENTER or DT_SINGLELINE or DT_NOPREFIX); //Draw vertical and horizontal centered text

Canvas.DrawText(Canvas.Handle, PChar(Column.Field.DisplayText), Length(Column.Field.DisplayText), Rect, DT_VCENTER or DT_SINGLELINE or DT_NOPREFIX);  //Draw vertical centered and horizontal left justified text

如何在DBGrid上绘制垂直居中的内容

1 个答案: