Author: Tomas Rutkauskas
How to display multiple lines in a single cell of a TStringGrid
Answer:
Solve 1:
It is fairly easy to draw such text in an OnDrawCell handler. However the standard
inplace editor of a grid is not well prepared to handle cells higher than one line.
1
2 procedure TForm1.StringGrid1DrawCell(Sender: TObject; Col, Row: Integer;
3 Rect: TRect; State: TGridDrawState);
4 var
5 S: string;
6 drawrect: TRect;
7 begin
8 S := (Sender as TStringGrid).Cells[Col, Row];
9 if Length(S) > 0 then
10 begin
11 drawrect := rect;
12 DrawText((Sender as TStringGrid).canvas.handle, Pchar(S), Length(S), drawrect,
13 DT_CALCRECT or DT_WORDBREAK or DT_LEFT);
14 if (drawrect.bottom - drawrect.top) > (Sender as TStringGrid).RowHeights[row]
15 then
16 (Sender as TStringGrid).RowHeights[row] := (drawrect.bottom - drawrect.top)
17 else
18 begin
19 drawrect.Right := rect.right;
20 (Sender as TStringGrid).canvas.fillrect(drawrect);
21 DrawText((Sender as TStringGrid).canvas.handle, Pchar(S), Length(S),
22 drawrect, DT_WORDBREAK or DT_LEFT);
23 end;
24 end;
25 end;
It will automatically adjust the row height to larger values if needed. The main
problem is that it will not automatically decrease the row height if the text would
fit into a smaller row. It cannot do that since there may be other cells in the row
that need a taller row. You could fix that problem by setting the rowheigh back to
the defaultrowheight when you change the cell data for a row, that would trigger a
redraw and that in turn would adjust the rowheight to what is needed. It would
cause some flicker, though.
Solve 2:
This is a unit that enables word-wrap in a cell of a TStringGrid:
26 unit Unit1;
27
28 interface
29
30 uses
31 SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
32 Forms, Dialogs, ExtCtrls, Grids;
33
34 type
35 TForm1 = class(TForm)
36 StringGrid1: TStringGrid;
37 Panel1: TPanel;
38 procedure StringGrid1DrawCell(Sender: TObject; Col, Row: Longint;
39 Rect: TRect; State: TGridDrawState);
40 private
41 { Private declarations }
42 public
43 { Public declarations }
44 end;
45
46 var
47 Form1: TForm1;
48
49 implementation
50
51 {$R *.DFM}
52
53 procedure TForm1.StringGrid1DrawCell(Sender: TObject; Col, Row: Longint;
54 Rect: TRect; State: TGridDrawState);
55 var
56 A: array[0..255] of char;
57 drawrect: TRect;
58 begin
59 StrPCopy(A, (Sender as TStringgrid).Cells[Col, Row]);
60 if StrLen(A) > 0 then
61 with (Sender as TStringgrid) do
62 begin
63 drawrect := rect;
64 {Note that the first DrawText uses the DT_CALCRECT flag to calculate a new
65 value for drawrect. This value is used to set the RowHeights
66 parameter if necessary.}
67 DrawText(canvas.handle, A, -1, drawrect, DT_CALCRECT or DT_WORDBREAK or
68 DT_LEFT);
69 if (drawrect.bottom - drawrect.top) > RowHeights[Row] then
70 RowHeights[row] := (drawrect.bottom - drawrect.top)
71 else
72 begin
73 drawrect.right := rect.right;
74 canvas.fillrect(drawrect);
75 DrawText(canvas.handle, A, -1, drawrect, DT_WORDBREAK or DT_LEFT);
76 end;
77 end;
78 end;
79
80 end.
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