[SOLVED] Showing complete memo text in dbgrid?
lazarus / 16-Databases

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BigChimp · 2012-03-11 13:29

Current Lazarus, FPC fixes 2.6
Asked this before but got no further, so trying again...

I've got a dbgrid with memo fields (from a DBF file). In many cases,
those memo fields contain not that much text at all.
By default, I think a memo field shows up as (Memo) in a dbgrid, which
is a bit... useless.

I would like to
show the full text of the cells. If the text is too big, it can be
truncatedoptionally: in the selected cell, show scrollbars that allow
the user to view the entire cell text
Having read the grids wiki page (but without Delphi experience) I've
cobbled together this code, which doesn't work - it doesn't seem to
paint correctly:
Code: [Select]procedure TForm1.ResultsGridDrawColumnCell(Sender:
TObject; const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);
// Draw memo text instead of (Memo)
// Note: grid DefaultDrawing property must be off to avoid duplicate
drawing
// To get this, I basically copied the existing DefaultDrawColumnCell
procedure
// but tested for memo first. If no memo, pass on to default
procedure.
// Maybe slower, more complicated, but it allows for changes in the
// core Lazarus DefaultDrawColumnCell procedure.
var
  OverrideDraw: boolean; //determine if we're going to override
drawing
  S: string;
  F: TField;
  DataRow: Integer;
begin
  OverrideDraw:=false;
  try
    F := Column.Field;
    if F.DataType = ftMemo then
    begin
      OverRideDraw:=true;
    end;
  except
    on E: exception do
    begin
      // We might have an inactive datalink or whatever,
      // in that case, pass on our problems to the existing
      // procedure.
      //showMessage('Exception: ' + E.Classname + '/' + E.Message);
      OverRideDraw:=false;
    end;
  end;

  if OverRideDraw=false then
  begin
    // Call normal procedure to handle drawing for us.
    ResultsGrid.DefaultDrawColumnCell(Rect,DataCol,Column,State);
  end
  else
  begin
    // Get to work displaying our memo contents
    // Basically shamelessly ripped from
    // DefaultDrawColumnCell
    // maybe fix something for first/header row
    if F<>nil then
    begin
      //DO display memo ;)
      S := F.AsString; //DisplayText will only show (Memo)
    end
    else
    begin
      S := '';
    end;
    //Actual drawing, taken from Grids.DrawCellText coding:
    ResultsGrid.Canvas.TextRect(Rect,Left,Top, S);
  end;
end;
Help welcome.

Project source code can be found under the outputparser directory in
https://bitbucket.org/reiniero/db2securityscript/src  (You can
download the code as a zip, too)

Thanks!

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User137 · 2012-03-11 14:57

Quote from: BigChimp on March 11, 2012, 02:29:06 pmCode:
[Select]procedure TForm1.ResultsGridDrawColumnCell(Sender: TObject;
const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);
...
    ResultsGrid.Canvas.TextRect(Rect,Left,Top, S);
...
Are you sure that's right parameters? Left and Top properties are the
coordinates of the Form1, not specific cell you are propably trying to
draw. Rect.Left and Rect.Top may give the position where cell is.

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BigChimp · 2012-03-11 16:19

Thanks User137, no I'm not sure at all, I was basically copy-pasting
everything I could find...

I tried it and it works - thanks a lot!

Now I just need to redraw the grid when some event (OnDraw or
whatever) fires -  when I display a messagebox, the grid doesn't
redraw...
Back to the wiki grids page - but at least I've got the right text
now.

Thanks again!

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christensen · 2016-09-06 19:06

Hi BigChimp,

Could you please give detail how do you solve.
I have a few dbf tables and some of them contain memo field, usually
the last column and i want to display it in TDBGrid.

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engkin · 2016-09-06 19:15



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LacaK · 2016-09-07 05:35

I have found:
http://forum.lazarus.freepascal.org/index.php/topic,16300.0.html
or you can play with TField.OnGetText event
http://www.freepascal.org/docs-html/fcl/db/tfield.ongettext.html

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christensen · 2016-09-07 06:25

Thanks,

I've tried like on the first link, but it returns me empty cell. When
i click on the cell it return (MEMO)

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gduck · 2017-03-29 09:08

Change last line!

ResultsGrid.Canvas.TextRect(Rect,Rect.Left,Rect.Top, S);

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usef74 · 2019-10-23 11:04

in OnGetText  use below Code:

procedure TFrmListKartable.ADOQuery1CommentGetText(Sender: TField;
  var Text: string; DisplayText: Boolean);
begin
 Text:= TField(Sender).AsString;
end;