让delphi的DBGrid能自适应列宽

///////Begin Source

uses

Math;

function DBGridRecordSize(mColumn: TColumn): 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: TDBGrid; 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 }

///////End Source

///////Begin Demo

procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;

DataCol: Integer; Column: TColumn; State: TGridDrawState);

begin

DBGridRecordSize(Column);

end;

procedure TForm1.Button2Click(Sender: TObject);

begin

DBGridAutoSize(DBGrid1);

end;

///////End Demo