Сохранение и чтение динамического массива из файла

Tother=record
i:integer;
a:byte;
end;
 
var b:array of Tother;

// Запись
AssignFile(myFile, 'Test.txt');
ReWrite(myFile);
for i := 0 to High(b) do
  Write(myFile, b[i]);
CloseFile(myFile);
 
// Чтение
i := 0;
AssignFile(myFile, 'Test.txt');
Reset(myFile);
while not Eof(myFile) do
begin
  SetLength(b, i+1);
  Read(myFile, b[i]);
  inc(i);
end;
CloseFile(myFile);

var a:integer;
begin
a:=filesize(f) div sizeof(Tother);
setlength(b,a);
read(f,b);

reset(f);
n:=filesize(f);
for i:=0 to n-1 do
read(f,a[i]);

 Tpoint = record  
    pointX:integer;  
    pointY:integer;  
    pointtype:byte;
 
  end;
 
var
fileobjects: file of Tpoint;
 
AssignFile(fileobjects,getcurrentdir+'\project\'+filecontent.objectfilename);
Reset(fileobjects);
i:=filesize(fileobjects);
for n:=0 to i-1 do read(fileobjects,objects[i]);
CloseFile(fileobjects);

AssignFile(fileobjects, Getcurrentdir+'\project\'+filecontent.objectfilename); 
     ReWrite(fileobjects);
      for i := 0 to length(objects)-1 do
      Write(fileobjects, objects[i]);
     CloseFile(fileobjects);