Showmessage MessageBox MessageDlg long string

[k1attila1]

Hello

Showmessage, MessageBox, MessageDlg wrap/break the line if string is long (eg 100 char)

Does anybody know any solution or it is OS problem (Win10) ?

thank you Attila

[Handoko]

Tested ShowMessage's wrapping behavior on Lazarus 1.6.4 FPC 3.0.2 on my Ubuntu Mate 16.10 computer. And this is the test result:

- The message will be wrapped on char 32 if the line is too long.

- The message won't be wrapped nor truncated even it exceeds my screen width, if the string doesn't contain space (chr 32).

This is the code I used:

Code: Pascal  [Select][+][-]

1. unit Unit1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes, SysUtils, Forms, Controls, Dialogs, StdCtrls;
9.  
10. type
11.  
12.   { TForm1 }
13.  
14.   TForm1 = class(TForm)
15.     Button1: TButton;
16.     procedure Button1Click(Sender: TObject);
17.   private
18.     { private declarations }
19.   public
20.     { public declarations }
21.   end;
22.  
23. var
24.   Form1: TForm1;
25.  
26. implementation
27.  
28. {$R *.lfm}
29.  
30. { TForm1 }
31.  
32. procedure TForm1.Button1Click(Sender: TObject);
33. var
34.   i: Integer;
35.   S: string;
36. begin
37.  
38.   S := '';
39.   for i := 1 to 20 do
40.     S := S + IntToStr(i)+'-123456 '; // has chr 32
41.   ShowMessage(S);
42.  
43.   S := '';
44.   for i := 1 to 20 do
45.     S := S + IntToStr(i)+'-123456x'; // no chr 32
46.   ShowMessage(S);
47.  
48. end;
49.  
50. end.

[ASerge]

Does anybody know any solution or it is OS problem (Win10) ?

What is solution?

My test. Windows 7 x64.
Dialogs.ShowMessage, Application.MessageBox, Dialogs.MessageDlg wrap after 59 chars if text contain space, or show 56 chars with '...' on single line without wrap.
Windows.MessageBox always wrap text. After 73 chars or early, if text contain space.

[Handoko]

So the ShowMessage's behavior is OS depended. My test never got a '...' even the string's length is 491 (for i := 1 to 50).

[k1attila1]

Thank You

So it is OS problem and not Lazarus.

Thank You again Attila

[balazsszekely]

Hi Attila,

Try the following code, it works on my win10:

Code: Pascal  [Select][+][-]

1. function MessageDlgEx(const AMsg: string; ADlgType: TMsgDlgType;
2.   AButtons: TMsgDlgButtons; AParent: TForm): TModalResult;
3. var
4.   MsgFrm: TForm;
5. begin
6.   MsgFrm := CreateMessageDialog(AMsg, ADlgType, AButtons);
7.   try
8.     MsgFrm.Position := poDefaultSizeOnly;
9.     MsgFrm.FormStyle := fsSystemStayOnTop;
10.     MsgFrm.Left := AParent.Left + (AParent.Width - MsgFrm.Width) div 2;
11.     MsgFrm.Top := AParent.Top + (AParent.Height - MsgFrm.Height) div 2;
12.     Result := MsgFrm.ShowModal;
13.   finally
14.     MsgFrm.Free
15.   end;
16. end;
17.  
18. procedure TForm1.Button1Click(Sender: TObject);
19. begin
20.   MessageDlgEx('fadfa afdfad afdad fafsd faf af af ads dddddddddddddddddddddddd dddddddddddddddddddddddd dddddddddddddddddddddddd dafdsad fasdfa daf',
21.                 mtInformation, [mbOk], Form1);
22. end;        
23.  

[k1attila1]

Thank you , Sir !

It is a good solution.

Attila

[Zoran]

Another solution is to replace spaces with non-breaking spaces:

Code: Pascal  [Select][+][-]

1. const
2.   NonBreakingSpace: String = Char($C2) + Char($A0); // non-breaking space (utf8-encoded)
3.  
4. procedure MyShowMessage(const aMsg: String);
5. begin
6.   ShowMessage(StringReplace(aMsg, Char(32), NonBreakingSpace, [rfReplaceAll]));
7. end;
8.  
9. function MyMessageDlg(const aMsg: string; DlgType: TMsgDlgType;
10.             Buttons: TMsgDlgButtons; HelpCtx: Longint): TModalResult;
11. begin
12.   Result := MessageDlg(StringReplace(aMsg, Char(32), NonBreakingSpace, [rfReplaceAll]),
13.     DlgType, Buttons, HelpCtx);
14. end;
15.  
16.  

EDIT: No, GetMem's solution is better, as line breaking occurs not only on spaces, but also on other charactes which can appear in your message (dashes, tabs, ...), and these aren't handled by my code.

[k1attila1]

Thank you Zoran !

I study your solution too ,maybe useful for another problem.

Attila