Freaky GroupBox caption problem

[KempCGDR]

Hi, I'm having a really wierd problem wiht my GroupBox captions.

If I have code such as the following:

aPhrase := 'Second half';
grpWhatever.caption := Concat('Something - ' , aPhrase , ' ...');

Nothing after the variable shows in the caption, it's just cut off (this also happens using + between each part instead of using the concat function, so it's not a problem with that function).

If I do the following:

grpWhatever.caption := Concat('Something - ' , 'Second half' , ' ...');

It all works as expected. So my question, what's going on? I'm completely confused here as to why it fails.

 

[PsiMatrix]

I created a simple app to try and reproduce the problem you described. I was not successful. My guess is that you may not have enough visible space on the groupbox to show the remaining area. Here is a sample app.

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

type
TForm1 = class(TForm)
gbx: TGroupBox;
Button1: TButton;
Button2: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
gbx.Caption := Concat('Something + ' , 'Do something', ' ...Blah blah');
end;

procedure TForm1.Button2Click(Sender: TObject);
var
aPh : string;
begin
aPh := 'Do Something';
gbx.Caption := Concat('Something + ', aPh, ' ...Blah blah');
end;

end.

 

[PsiMatrix]

FYI,

According to the documentation, using the plus(+) operator performs the same function as concat and is faster.

 

[KempCGDR]

I don't think it's a space limitation, because if I type it to say exactly the same as it would do using the variable then it displays the whole string.

I've just tried it in a new app and it works exactly as it should. Strange. It still doesn't work in my app I'm working on using exactly the same code for that particular bit.

 

[KempCGDR]

I'm an idiot. It suddenly occured to me that the string I'm putting in there is pulled from a file and is zero-terminated so the caption ends at that point. My problem now is how to stop it being zero-terminated.

Code such as:

copy(sectionName,1,length(sectionName)-1)

doesn't appear to work, I can set the length modifier ( -1 in the example ) to as much as I want and it still just spits out the whole string.

 

[buho]

Lets say the text you are loading from the file is in FirstString. Try:

var
  WorkStr : AnsiString;
begin
  SetLength(WorkStr, Length(FirstStr);
  Move(FirstStr[1], WorkStr[1], Length(FirstStr));
end;

Not sure it will work as I've never seen the problem you are having... What Delphi version are you using?

buho (A).

 

[KempCGDR]

Ah, another thought. The string is a set length, but the termination happens after the actual content, hence why pulling one off the size didn't work before. The string could be:

"STUFF# "

with the # denoting the terminating character.

I've fixed it though, came up with this:

i := 1;
done := false;

repeat
   if sectionName[i] <> chr(0) then
      tempStr := tempStr + sectionName[i]
   else
      done := true;
   inc(i);
until done;

there's probably a better way though.

 

[richardchaven]

I do things like

SetLength(ThisString, 1000);
//  call an API function that stuffs something in PChar(ThisString)
SetLength(ThisString, StrLen(PChar(ThisString)));

Cheers