Hello, my name is Andrew. I have been using Delphi since version 3.0 (around 1997).
I have designed this home page in order to share my experiences of Delphi here with other people.
1. Delphi tutorial
First of all i'd like to show first VCL component written five two years ago about. This
database grid with one additional property (LinesPerRow). This property allow to diplay the memo fields values
directly in the grid cells. I hope this tutorial will be useful and help you to create the another
Db-aware VCL components.
implementation
//------------------------------------------------------------------------------
constructor TMLinesDbGrid.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FLinesPerRow := 1;
end;
//------------------------------------------------------------------------------
procedure TMLinesDbGrid.LayOutChanged;
var
PixelsPerRow, PixelsTitle, I: Integer;
begin
inherited LayOutChanged;
Canvas.Font := Font;
PixelsPerRow := Canvas.TextHeight('Wg') + 3;
if dgRowLines in Options then
Inc (PixelsPerRow, GridLineWidth);
Canvas.Font := TitleFont;
PixelsTitle := Canvas.TextHeight('Wg') + 4;
if dgRowLines in Options then
Inc (PixelsTitle, GridLineWidth);
// set number of rows
//RowCount := 1 + (Height - PixelsTitle) div
// (PixelsPerRow * FLinesPerRow);
// set the height of each row
DefaultRowHeight := PixelsPerRow * FLinesPerRow;
RowHeights [0] := PixelsTitle;
for I := 1 to RowCount - 1 do
RowHeights [I] := PixelsPerRow * FLinesPerRow;
end;
//------------------------------------------------------------------------------
procedure TMLinesDbGrid.DrawColumnCell(const Rect: TRect;
DataCol: Integer; Column: TColumn; State: TGridDrawState);
var
Bmp: TBitmap;
OutRect: TRect;
I : Integer;
begin
if FLinesPerRow = 1 then
inherited DrawColumnCell(Rect, DataCol, Column, State)
else
begin
If Assigned (onDrawColumnCell) then
onDrawColumnCell(Self, Rect, DataCol, Column, State);
// clear area
Canvas.FillRect (Rect);
// copy the rectangle
OutRect := Rect;
// restrict output
InflateRect (OutRect, -2, -2);
// output field data
if (Column.Field is TGraphicField) {or (Column.Field is TBlobField)} then
begin
Bmp := TBitmap.Create;
try
Bmp.Assign (Column.Field);
Canvas.StretchDraw (OutRect, Bmp);
finally
Bmp.Free;
end;
end
else If (Column.Field is TMemoField) or (Column.Field is TStringField) then
begin
DrawText (Canvas.Handle,
PChar (Column.Field.AsString),
Length (Column.Field.AsString),
OutRect, dt_WordBreak or dt_NoPrefix);
end
else // draw single line vertically centered
DrawText (Canvas.Handle,
PChar (Column.Field.DisplayText),
Length (Column.Field.DisplayText),
OutRect, {dt_vcenter or} dt_SingleLine or dt_NoPrefix);
{DrawText (Canvas.Handle,
PChar (Column.Field.AsString),
Length (Column.Field.AsString),
OutRect, dt_WordBreak or dt_NoPrefix) }
end;
end;
//------------------------------------------------------------------------------
procedure TMLinesDbGrid.SetLinesPerRow(Value: Integer);
begin
if Value <> FLinesPerRow then
begin
FLinesPerRow := Value;
LayoutChanged;
end;
end;
//------------------------------------------------------------------------------
procedure Register;
begin
RegisterComponents('Data Controls', [TMLinesDbGrid]);
end;
//------------------------------------------------------------------------------
end.
I like the table tennis :), the mountaineering with my friends.
My best friend is Patrik and we are more than just friends. We are gays.
Here you can find the some links concerning of my interests:
