How do I load a chess board into program once saved? - delphi

Question

I have a procedure that saves a chess board into a text file. I am trying to read the board back in to the program once saved. When I call this procedure I get this error.
Code which I have for loading in board.
Procedure LoadBoard(Var Board : Tboard);
var
fptr:text;
i,j,x:integer;
line:string;
load:char;
begin
Write('Do you want a load a game? (Enter Y for yes)');
Readln(load);
If (Ord(load) >= 97) and (Ord(load) <= 122)
Then load := Chr(Ord(load) - 32);
if load='Y' then
begin
assignfile(fptr,'SBoard.txt');
reset(fptr);
i:=1;
repeat
readln(fptr,line);
j:=1;
x:=1;
repeat
begin
if (line[x]<>',') and (line[x+1]<>',')
then
begin
Board[i,j][1]:=line[x];
Board[i,j][2]:=line[x+1];
end;
if line[x]=','
then
j:=j+1;
x:=x+1;
end;
until j=9;
i:=i+1;
until i=9;
close(fptr);
end;
end;

Answer 1

You get the Access Violation exception because the string members in your Board array are empty (length is zero) and therefore have no accessible character positions.
To fix your present code, you should use SetLength() on each string member before you assign content to the character positions. You have not shown what the strings contain, so only you know what the set length should be.
On the other hand, in previous answer to your questions you have been adviced several other methods to save your chess board. You should review those and possibly choose one of them. It would also be polite to respond to those answers and maybe tell why you did not select them. Maybe we were not able to explain the benefits.

Answer 2

You are over complicating things by using a Text file and saving your board line by line.
I think you should use a TStringList for saving and loading :
Const
BoardDimension = 8;
BoardFileName = 'SBoard.txt';
Type
TBoard = Array [1 .. BoardDimension, 1 .. BoardDimension] Of String;
procedure SaveBoard(Board: TBoard);
var
i, j: Integer;
Line, BoardFile: TStringList;
begin
BoardFile := TStringList.Create;
Line := TStringList.Create;
for i := 1 to BoardDimension do
begin
Line.Clear;
for j := 1 to BoardDimension do
Line.Add(Board[i, j]);
BoardFile.Add(Line.CommaText);
end;
Line.Free;
BoardFile.SaveToFile(BoardFileName);
BoardFile.Free;
end;
procedure LoadBoard(Board: TBoard);
var
i, j: Integer;
Line, BoardFile: TStringList;
begin
if not FileExists(BoardFileName) then
exit; // Show error message
BoardFile := TStringList.Create;
BoardFile.LoadFromFile(BoardFileName);
Line := TStringList.Create;
for i := 1 to BoardDimension do
begin
Line.CommaText := BoardFile[i];
for j := 1 to BoardDimension do
Board[i, j] := Line[j];
end;
Line.Free;
BoardFile.Free;
end;
And if you want to test the load an save proceudre you could do it like this :
procedure Test;
var
Board: TBoard;
BoardA: TBoard;
i, j: Integer;
begin
randomize;
for i := 1 to BoardDimension do
for j := 1 to BoardDimension do
Board[i, j] := Random(500).ToString;
SaveBoard(Board); //Save Board
LoadBoard(BoardA); //Load the file into a NEW board
for i := 1 to BoardDimension do //Comapre the two boards
for j := 1 to BoardDimension do
if Board[i,j] <> BoardA[i,j] then
raise Exception.Create('Wrong file format');
end;