Problem assigning string to Memo variable
Tristan Martinez
AMemo is a user-defined TMemo variable. I am attempting to assign a string
to the AMemo variable and then using the AMemo.Lines.Count to create a text
box large enough to contain the string.
Unfortunately, I always get the value 0 for AMemo.Lines.Count and the string
is never wrapped within the boundaries (I have the WordWrap property set to
true and the Width set to a value smaller than the lenght of the string).
If anyone can suggest a way to display a string that can be word-wrapped in
a predefined width and allow me to obtain the number of lines required, I
would greatly appreciate it.
Thanks in advance.
Tristan
Giannis kozikopulos
I don't know why but you can find out the maximum line number will ever
used by the following calculations.
maxlineno:=(Stringlength div maxlength) +1;
Hope this helps
Best Regards
Johnnie.
Peter Below (TeamB)
Let's get the nomenclature straight here: a memo is an object and you cannot
assign a string to an object variable. You can assign it to the Text property
of the memo, however, which is of type String.
> If anyone can suggest a way to display a string that can be word-wrapped in
> a predefined width and allow me to obtain the number of lines required, I
> would greatly appreciate it.
There is a way to "measure" a string for display using the API function
DrawText.
Var
r: TRect;
S: String;
Begin
S:= .....; // string to measure
r:= Rect( 0, 0, 250, 10 ); // allow 250 pixels width
canvas.font := somefont; // define font to use
DrawText(canvas.handle,
Pchar(S), Length(S), r,
dt_calcrect or dt_wordbreak or dt_left );
// r.bottom now contains the required height for the text
Note that this does not actually count lines but
r.bottom / Abs(somefont.height) should get you a good approximation for that.
Peter Below (TeamB) 10011...@compuserve.com)
No e-mail responses, please, unless explicitly requested!
Tristan Martinez
in
>> a predefined width and allow me to obtain the number of lines required, I
>> would greatly appreciate it.
>There is a way to "measure" a string for display using the API function
>DrawText.
Isn't it a feature of a TMemo object that allows a string to be assigned to
its text property and have that string Word Wrapped within the predefined
Width? This is where I am having difficulties.
When I perform this:
AMemo.Text := myString;
And then I try to find this:
LineCount := AMemo.Lines.Count;
I get the value 0.
When I try to reference the first line in AMemo.Text by doing:
AMemo.Lines[0];
I get a reference error. I wish some method that will allow me to word wrap
a string within a predefined width. I thought TMemo would let me do this,
am I wrong?
Thanks in advance.
Tristan
Rudy Velthuis
>When I perform this:
>
> AMemo.Text := myString;
>
>And then I try to find this:
>
> LineCount := AMemo.Lines.Count;
>
>I get the value 0.
>
>When I try to reference the first line in AMemo.Text by doing:
>
> AMemo.Lines[0];
>
>I get a reference error. I wish some method that will allow me to word wrap
>a string within a predefined width. I thought TMemo would let me do this,
>am I wrong?
Are you sure myString <> '' ? Otherwise, you would have an empty memo, so
Lines[0] would be invalid (which would match the fact that Lines.Count =
0).
If you want to display a word wrapped string, try TLabel also. And have a
look at the Win32 function DrawText, like Peter said. This has a lot of
options to draw text, including word wrap.
--
Rudy Velthuis
rvel...@gmx.net
http://members.xoom.com/RVelthuis
Rudy Velthuis
>Isn't it a feature of a TMemo object that allows a string to be assigned to
>its text property and have that string Word Wrapped within the predefined
>Width? This is where I am having difficulties.
Ok, I've done this:
Select New Application from the File menu.
In the form, drop a memo and leave it exactly as it is. Now it propably
contains the text Memo1. Also drop a Label component on it (Label1).
Doubleclick on the form (not on the memo or the label!) and enter this in
the FormCreate procedure in the editor:
procedure TForm1.FormCreate(Sender: TObject);
var
MyString: string;
begin
MyString := 'This is the first line of text, it must be a ' +
'bit longer than just a few characters.';
Memo1.Text := MyString;
Label1.Caption := IntToStr(Memo1.Lines.Count);
end;
Now press run and see what happens: the memo is word wrapped and the
label shows the number 2.
If this doesn't work, you have a serious problem. Try to re-install
Delphi 4 and apply D4 SP2 and D4 SP3 (or whatever version you use: D3,
D2).
--
Rudy Velthuis