DBGridEh自动适应列宽

自动调整列的宽度
function DBGridRecordSize(mColumn: TColumnEh): Boolean;
{ 返回记录数据网格列显示最大宽度是否成功 }
begin
  Result := False;
  if not Assigned(mColumn.Field) then Exit;
  mColumn.Field.Tag := Max(mColumn.Field.Tag,
  TDBGrid(mColumn.Grid).Canvas.TextWidth(mColumn.Field.DisplayText));
  Result := True;
end; { DBGridRecordSize }

function DBGridAutoSize(mDBGrid: TDBGridEh; mOffset: Integer = 5): Boolean;
{ 返回数据网格自动适应宽度是否成功 }
var
  I: Integer;
begin
  Result := False;
  if not Assigned(mDBGrid) then Exit;
  if not Assigned(mDBGrid.DataSource) then Exit;
  if not Assigned(mDBGrid.DataSource.DataSet) then Exit;
  if not mDBGrid.DataSource.DataSet.Active then Exit;
  for I := 0 to mDBGrid.Columns.Count - 1 do begin
   if not mDBGrid.Columns[i].Visible then Continue;
   if Assigned(mDBGrid.Columns[i].Field) then
     mDBGrid.Columns[i].Width := Max(mDBGrid.Columns[i].Field.Tag,
       mDBGrid.Canvas.TextWidth(mDBGrid.Columns[i].Title.Caption)) + mOffset
   else mDBGrid.Columns[i].Width :=
     mDBGrid.Canvas.TextWidth(mDBGrid.Columns[i].Title.Caption) + mOffset;
   mDBGrid.Refresh;
  end;
  Result := True;
end; { DBGridAutoSize }

// 应用代码

use Math;

procedure TForm1.DBGridEh1DrawColumnCell(Sender: TObject;
  const Rect: TRect; DataCol: Integer; Column: TColumnEh;
  State: TGridDrawState);
begin
  DBGridRecordSize(Column);
end;