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displaying text file content to a Tmemo

Posted on 2003-11-03
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Last Modified: 2010-04-05
 I am currently trying to write a program that reads the contents of a text file to display it into a Tmemo, i have written the following code, it does not compile! help please

procedure ReadFromFile(Memo1 :TMemo; '/root/test.txt':String);

var

OpenFile : TextFile;
Outstring: string;

begin

Memo1.Lines.Clear;
AssignFile(OpenFile, '/root/test.txt');
Reset(OpenFile);
ReadLn(OpenFile, Outstring);
Memo1.Lines.Add(Outstring);
CloseFile(OpenFile);
end;
end.

The error that i get is  at the first line " identifier expected but string constant found"  I Have tried some modifications on the program like  removing"; '/root/test.txt':String" which makes it compile successfully, but then when i run the program it does not read and display the contents of the text file in the Tmemo. what am i doing wrong? And i could I change this program for it to display the contents into edit boxes. Thanks
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Comment
Question by:itektas
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8 Comments
 
LVL 5

Expert Comment

by:arjanh
ID: 9674334
You can simply import a text file into a TMemo as follows:
Memo1.Lines.LoadFromFile('/root/test.txt');
0
 

Author Comment

by:itektas
ID: 9674382
I will try that now, but where in my code does it go?
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LVL 5

Expert Comment

by:arjanh
ID: 9674383
And line 1 sould read something like
procedure ReadFromFile(Memo1 :TMemo; FileName:String);

Within that procedure you then use
Memo1.Lines.Clear;
AssignFile(OpenFile, FileName );
Reset( OpenFile);
while not Eof( OpenFile ) do
begin
  ReadLn(OpenFile, Outstring);
  Memo1.Lines.Add(Outstring);
end;
CloseFile(OpenFile);

When you call ReadFromFile in your main program, you have to give the filename:
ReadFromFile( myMemo, '/root/test.txt' );
0
 
LVL 5

Expert Comment

by:arjanh
ID: 9674402
My earlier sugestion would become

procedure ReadFromFile(Memo1 :TMemo; FileName:String);
begin
  Memo1.Lines.Clear;
  Memo1.Lines.LoadFromFile( FileName );
end;

and again, somewhere in your program you would do
ReadFromFile( myMemo, '/root/test.txt' );
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Author Comment

by:itektas
ID: 9674524
when i do the following

procedure ReadFromFile (Memo1:TMemo; '/root/test.txt' :String);
begin
Memo1.Lines.Clear;
Memo1.Lines.LoadFromFile('/root/test.txt');
end;

the compiler doenst seem to like the first line at all! it keeps saying identifier expected but string constant found. I'm also a bit confused when you say that I need to include ReadFromFile(myMemo, '/root/test.txt'); Does that need to go somewhere else besides the implementation of the program? The same thing happens when i try the first program you told me, it doenst like the first line and says the same error ? thanks
0
 
LVL 5

Accepted Solution

by:
arjanh earned 20 total points
ID: 9674624
There are two things: you _define_ a procedure, and you _call_ it from somewhere.

The procedure is like a recipe: do something with the given ingredients (in this case a TMemo and a String). This procedure can load any text file into any TMemo. In this case, 'Memo1' is just a label for the procedure to know what TMemo to update.

Try adding a button to your application, and in the OnClick handler (just doubleclick the button in designer), add a call to this procedure:
ReadFromFile( Memo1, '/root/test.txt' );

Know when you click the button when running your app, the recipe will be executed, with ingredients Memo1 (the TMemo on your form) and the filename '/root/test.txt';

To play a bit more, try adding a second TMemo (Memo2) and button (Button2) to your app, and in the OnClick of Button2 add:
ReadFromFile( Memo2, '/root/test.txt' );

This will read the same text file into Memo2, using the exact same procedure (recipe)!

Good luck.
0
 

Author Comment

by:itektas
ID: 9677695
ok it works now!! I had to change one thing tho, whenever i put the filename into the procedure it would not compile, but it works when i remove it.

procedure  ReadFromFile (Memo1 :TMemo);
begin
Memo1.Lines.Clear;
Memo1.Lines.LoadFromFile('/root/test.txt');
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
ReadFromFile( Memo1);

thanks for that mate,
0
 

Expert Comment

by:computerprogramer
ID: 9683290
This was my code a whle ago ...

procedure button1.click (TSender: TObject)
begin
memo1.Loadfromfile ('c:\text.txt')
end;
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