ASCII-Zeichen aus einer Datei auslesen

[xZise]

Zitat von sakura:

Delphi-Quellcode:

with TFileStream.Create(FileName, foOpenRead) do
try
  while Position < Size do
  begin
    // und einfach auslesen...
  end;
finally
  Free;
end;

Und "inc(Position)" ist ein Byte "weiter"?

Zitat von mkinzler:

Versuch mal die Datei als Binärdatei anzusehen.

Wie programmiert man das am besten?

[edit]Ich habe folgenden Code gefunden:

Delphi-Quellcode:

const
  LEVELS = 4;
  ROWS = 12;
  COLS = 12;

type
  TDimArray = array [0..3] of Byte;
  TMatrix = packed array of array of array of Byte;

procedure RedimMatrix(var m: TMatrix; dim: array of Byte);
begin
  SetLength(m, LEVELS, ROWS, COLS);
end;

procedure SaveMatrix(m: TMatrix; fn: TFileName);
var
  dwDim, dwSize: Cardinal;
begin
  dwDim := (Length(m) shl 8 + Length(m[0])) shl 8 + Length(m[0, 0]);
  dwSize := Length(m) * Length(m[0]) * Length(m[0, 0]);
  with TFileStream.Create(fn, fmCreate) do
  try
    Write(dwDim, SizeOf(dwDim));
    Write(m[0], dwSize); // korrigiert
  finally
    Free;
  end;
end;

procedure LoadMatrix(var m: TMatrix; fn: TFileName);
var
  dwDim, dwSize: Cardinal;
  dim: TDimArray absolute dwDim;
begin
  with TFileStream.Create(fn, fmOpenRead or fmShareDenyWrite) do
  try
    Read(dwDim, SizeOf(dwDim));
    // SetLength(m, Hi(dwDim), Lo(dwDim) shr 8, dwDim and $FF); // fehlerhaft
    SetLength(m, dim[2], dim[1], dim[0]);
    dwSize := Length(m) * Length(m[0]) * Length(m[0, 0]);
    Read(m[0], dwSize); // korrigiert
  finally
    Free;
  end;
end;

{
procedure TestMatrix; 
const
  FN = 'c:\daten\dp\map.f2m';
var
  m: TMatrix;
  iLevel, iRow, iCol: Integer;
begin
  RedimMatrix(m, [LEVELS, ROWS, COLS]);
  for iLevel := Low(m) to High(m) do
    for iRow := Low(m[0]) to High(m[0]) do
      for iCol := Low(m[0, 0]) to High(m[0, 0]) do
        m[iLevel, iRow, iCol] := 48 + iLevel * 4 + iRow * iCol mod 10;
  SaveMatrix(m, fn);
  FillChar(m, SizeOf(m), 0);
  LoadMatrix(m, fn);
end;
}

procedure TestMatrix;
const
  FN = 'c:\daten\dp\map.f2m';
var
  m: TMatrix;
  iLevel, iRow, iCol: Integer;
  dwSize: Cardinal;
  okay: Boolean;
begin
  RedimMatrix(m, [LEVELS, ROWS, COLS]);
  dwSize := LEVELS * ROWS * COLS;
  for iLevel := Low(m) to High(m) do
    for iRow := Low(m[0]) to High(m[0]) do
      for iCol := Low(m[0, 0]) to High(m[0, 0]) do
        m[iLevel, iRow, iCol] := 48 + iLevel * 4 + iRow * iCol mod 10;
  SaveMatrix(m, fn);
  FillChar(m[0], dwSize, 0);
  LoadMatrix(m, fn);
  okay := True;
  for iLevel := Low(m) to High(m) do
    for iRow := Low(m[0]) to High(m[0]) do
      for iCol := Low(m[0, 0]) to High(m[0, 0]) do
        if m[iLevel, iRow, iCol] <> 48 + iLevel * 4 + iRow * iCol mod 10 then
          okay := False;
  WriteLn(IfThen(okay, 'fine', 'rats'));
end;

Aber der funktioniert in abgewandelter Form nicht mehr.

Delphi-Quellcode:

const
  LEVELS = 2;
  ROWS = 12;
  COLS = 12;

type
  TDimArray = array [0..3] of Byte;
  TMatrix = packed array of array of array of Byte;

procedure RedimMatrix(var m: TMatrix; dim: array of Byte);
begin
  SetLength(m, LEVELS, ROWS, COLS);
end;

procedure SaveMatrix(m: TMatrix; fn: TFileName);
var
  dwDim, dwSize: Cardinal;
begin
  dwDim := (Length(m) shl 8 + Length(m[0])) shl 8 + Length(m[0, 0]);
  dwSize := Length(m) * Length(m[0]) * Length(m[0, 0]);
  with TFileStream.Create(fn, fmCreate) do
  try
    Write(dwDim, SizeOf(dwDim));
    Write(m[0], dwSize); // korrigiert
  finally
    Free;
  end;
end;

procedure LoadMatrix(var m: TMatrix; fn: TFileName);
var
  dwDim, dwSize: Cardinal;
  dim: TDimArray absolute dwDim;
begin
  with TFileStream.Create(fn, fmOpenRead or fmShareDenyWrite) do
  try
    Read(dwDim, SizeOf(dwDim));
    // SetLength(m, Hi(dwDim), Lo(dwDim) shr 8, dwDim and $FF); // fehlerhaft
    SetLength(m, dim[2], dim[1], dim[0]);
    dwSize := Length(m) * Length(m[0]) * Length(m[0, 0]);
    Read(m[0], dwSize); // korrigiert
  finally
    Free;
  end;
end;

procedure TestMatrix;
const
  FN = 'c:\map.f2m';
var
  m: TMatrix;
  iLevel, iRow, iCol: Integer;
  dwSize: Cardinal;
  okay: Boolean;
begin
  RedimMatrix(m, [LEVELS, ROWS, COLS]);
  dwSize := LEVELS * ROWS * COLS;
  Form1.Memo1.Text := '';
  for iLevel := Low(m) to High(m) do
    for iRow := Low(m[0]) to High(m[0]) do
    begin
       Form1.Memo1.Text := Form1.Memo1.Text + #13#10;
      for iCol := Low(m[0, 0]) to High(m[0, 0]) do
      begin
        m[iLevel, iRow, iCol] := Random(256);
        Form1.Memo1.Text := Form1.Memo1.Text + ' ' + IntToStr(m[iLevel, iRow, iCol]);
      end;
    end;

  SaveMatrix(m, fn);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  TestMatrix;
end;

procedure TForm1.Button2Click(Sender: TObject);
const
  FN = 'c:\map.f2m';
var
  m: TMatrix;
  iLevel, iRow, iCol: Integer;
  dwSize: Cardinal;
  okay: Boolean;
begin
  LoadMatrix(m, fn);
  Form1.Memo1.Text := '';
  for iLevel := Low(m) to High(m) do
    for iRow := Low(m[0]) to High(m[0]) do
    begin
       Form1.Memo1.Text := Form1.Memo1.Text + #13#10;
      for iCol := Low(m[0, 0]) to High(m[0, 0]) do
      begin
        Form1.Memo1.Text := Form1.Memo1.Text + ' ' + IntToStr(m[iLevel, iRow, iCol]);
      end;
    end;
end;

end.