A Tsavedialog control that is used to derive the text after the system returns an error to the specified file was not found, but if the text does not exist, or text can be generated, if the text already exists, then the text will be added to the original text, and had no choice but to do an error message, write a text to prevent repeated, how to change or to an error, ask how to change? Ever thought to change?

Procedure TMOText. ConVert (const Dir: String).
Var
I, v: Integer;
A: TextFile;
S: a String;
The begin
AssignFile (A, Dir);
Try
Append (A);
Except,
Rewrite (A);
end;
The begin
Writeln (A, 'start');
end;
S:=';
For I:=0 to adodsCustomer1. Do RecordCount - 1
The begin
For v:=0 to adodsCustomer1. Fields. Do the Count - 1
The begin
S:=S + adodsCustomer1. Fields. The Fields [v]. AsString;
If v & lt; AdodsCustomer1. Fields. Then the Count - 1
S:=S + '|'.
end;
AdodsCustomer1. Next;
Writeln (A, s);
S:=';
end;
The begin
Writeln (A, 'END');
end;
CloseFile (A);
end;

Procedure TMOText. Button3click (Sender: TObject);
Var
A: TextFile;

The begin
If SaveDia. Execute then
The begin
If fileexists (SaveDia. FileName) then
The begin
Showmessage (' file already exists);
End the else
ConVert (SaveDia FileName);
end;
end;

CodePudding user response:

Didn't understand what you want to do,
Is to want to save a file, if the file already exists, do not save? Or if the file already exists additional content into the file?

CodePudding user response:

Just want to put the database of the contents, according to the fixed format export text, encounter problems when exported, wanted to not create a new file, then replace, the results make a mistake

CodePudding user response:

If the file already exists, it is easy to have replace ah, how to get so complicated?

 
Var 
F: TextFile; 
Fname: string; 
The begin 
Fname:='c: \ 1. TXT'; 
The DeleteFile (fname);//regardless of whether there is performed first delete 
AssignFile (f, fname); 
Try 
Rewrite (f); 
//write content 
The finally 
CloseFile (f); 
end; 

CodePudding user response:

If the file delete not to drop, check whether the file opened by other processes has not been closed,

 
Var 
F: TextFile; 
Fname: string; 
The begin 
Fname:='c: \ 1. TXT'; 
If DeleteFile (fname) then 
The begin 
AssignFile (f, fname); 
Try 
Rewrite (f); 
//write content 
The finally 
CloseFile (f); 
end; 
End 
The else 
Raise the Exception. CreateFmt (' delete file % s failure, [fname]); 
end;