Delphi保存/加载动态数组失败 [英] Delphi Saving/Loading Dynamic Arrays Failed

问题描述

我认为这样做会像我的家庭作业那样是一个问题，但是我仍然在使用复制代码，使用它并尝试了解它'阶段，这是我发现这个主题的最有活力的事情。

我有一个记录：

  type 
 Card = record 
名称：string; 
向上，向右，向左，向下，标记：单个; 
 IDNumber：Integer; 
结束
  

该记录数组：

  var 
 ArrayCard：数组卡; 
  

我想知道如何将这种动态数组存储/加载到/文件。

尝试使用这段代码： http://www.pascalgamedevelopment.com/showthread.php?6319-save-load-a-dynamic-array
像这样：

 过程TMainFrom.WriteMyData; 
 
 Var 
 FS：TFileStream; 
 I，iSize：Integer; 
 TmpPath：string; 
 
开始
 TmpPath：= TPath.Combine（TPath.GetDocumentsPath，'Cards.dat'）; 
 FS：= TFileStream.Create（TmpPath，fmOpenWrite）; 
 iSize：= Length（ArrayCard）; 
 FS.WriteBuffer（iSize，SizeOf（iSize））; 
对于I：= 0到iSize  -  1 Do 
 FS.WriteBuffer（ArrayCard [I]，SizeOf（Card））; 
 FS.Free; 
结束; 
  

它似乎工作到目前为止，但后来我尝试加载它像这样：

 过程TMainFrom.ReadMyData; 
 
 Var 
 FS：TFileStream; 
 I，iSize：Integer; 
 TmpPath：string; 
 TempCard：卡; 
 
开始
 TmpPath：= TPath.Combine（TPath.GetDocumentsPath，'Cards.dat'）; 
 FS：= TFileStream.Create（TmpPath，fmOpenRead）; 
 FS.ReadBuffer（iSize，SizeOf（iSize））; 
 SetLength（ArrayCard，iSize）; 
对于I：= 0到iSize  -  1 Do 
开始
 FS.ReadBuffer（TempCard，SizeOf（Card））; 
 ArrayCard [I]：= TempCard; // It breaks Here ...观看列表：TempCard无法访问的价值
结束; 
 FS.Free; 
结束; 
  

我在模块中收到异常EAccessViolation ...

然后我也尝试过这样的事情： delphi保存并加载动态数组
它加载的数组具有正确的项目数量，但它们都为空或空白：

 程序TMainFrom.SaveCardsToFile; 
 var 
流：TStream; 
 L：整数; 
 TmpPath：string; 
 ICount：Integer; 
 strm：TMemoryStream; 
 
 begin 
 TmpPath：= TPath.Combine（TPath.GetDocumentsPath，'Cards.bin'）; 
 
 Stream：= TFileStream.Create（TmpPath，fmCreate）; 
 L：=长度（ArrayCard）; 
 Stream.WriteBuffer（L，SizeOf（L））; 
 Stream.WriteBuffer（指针（ArrayCard）^，L * SizeOf（Card））; 
 Stream.Free; 
结束
 
程序TMainFrom.LoadCardsFromFile; 
 var 
流：TStream; 
 L：LongWord; 
 TmpPath：string; 
 
 begin 
 TmpPath：= TPath.Combine（TPath.GetDocumentsPath，'Cards.bin'）; 
 
 Stream：= TFileStream.Create（TmpPath，fmOpenRead）; 
 Stream.ReadBuffer（L，SizeOf（L））; 
 SetLength（ArrayCard，L）; 
 Stream.ReadBuffer（指针（ArrayCard）^，L * SizeOf（Card））; 
 Stream.Free; 
结束
  

解决方案

有一些帮助，我设法重制我的代码正常工作
首先，我需要使字符串像 string [20] ，但无法编译android，所以我修改了我的记录，使用数组char 像这样：

 键入
 EventString =数组[0..20]的Char; 
 
卡=记录
名称：EventString; // string [20] 
向上，向右，向左，向下，标记：单个; 
 IDNumber：Integer; 
结束
  

然后我修改了我的保存/加载过程，使用TFileStream代替TStream和for循环： p>

 程序TMainFrom.SaveCardsToFile; 
 var 
流：TFileStream; 
 L：整数; 
 TmpPath：string; 
 n：整数; 
 
 begin 
 TmpPath：= TPath.Combine（TPath.GetDocumentsPath，'Cards.bin'）; 
 Stream：= TFileStream.Create（TmpPath，fmCreate）; 
 L：=长度（ArrayCard）-1; 
 for n：= 0 to L do 
 begin 
 Stream.WriteBuffer（ArrayCard [n]，SizeOf（Card））; //保存
 end; 
 Stream.Free; 
结束
 
程序TMainFrom.LoadCardsFromFile; 
 var 
流：TFileStream; 
 L：LongWord; 
 TmpPath：string; 
 n：整数; 
 
 begin 
 TmpPath：= TPath.Combine（TPath.GetDocumentsPath，'Cards.bin'）; 
 Stream：= TFileStream.Create（TmpPath，fmOpenRead）; 
 SetLength（ArrayCard，Round（Stream.Size / SizeOf（Card）））; 
 L：=长度（ArrayCard）-1; 
 for n：= 0 to L do 
 begin 
 Stream.ReadBuffer（ArrayCard [n]，SizeOf（Card））; //加载
 ListCard.Items.Add（ArrayCard [n] .Name）; //只需将卡名称添加到列表框
 end; 
 Stream.Free; 
 
 end; 
  

现在它工作得很好。

I think this will look like 'do my homework' kind of a question, but I'm still at the 'copy code, use it and try to understand it' phase, and this is the most active thing I know of for posting questions of this theme.

I have a record:

type
  Card = record
    Name: string;
    Up,Right,Left,Down,Mark: Single; 
    IDNumber: Integer;
    end;

And array of that record:

var
  ArrayCard: array of Card;

And I wanted to know how can a dynamic array of this kind be stored/loaded to/from a file.

Tried using this piece of code: http://www.pascalgamedevelopment.com/showthread.php?6319-save-load-a-dynamic-array like this:

Procedure TMainFrom.WriteMyData;

  Var
    FS : TFileStream;
    I,iSize : Integer;
    TmpPath: string;

  Begin
    TmpPath:= TPath.Combine(TPath.GetDocumentsPath, 'Cards.dat');
    FS := TFileStream.Create(TmpPath, fmOpenWrite);
    iSize:= Length(ArrayCard);
    FS.WriteBuffer(iSize,SizeOf(iSize));
  For I := 0 To iSize - 1 Do
    FS.WriteBuffer(ArrayCard[I],SizeOf(Card));
  FS.Free;
  End;

An it seems to work so far, but then I try to load it like this:

Procedure TMainFrom.ReadMyData;

  Var
    FS : TFileStream;
    I,iSize : Integer;
    TmpPath: string;
    TempCard : Card;

  Begin
    TmpPath:= TPath.Combine(TPath.GetDocumentsPath, 'Cards.dat');
    FS := TFileStream.Create(TmpPath, fmOpenRead);
    FS.ReadBuffer(iSize,SizeOf(iSize));
    SetLength(ArrayCard,iSize);
  For I := 0 To iSize - 1 Do
    Begin
    FS.ReadBuffer(TempCard,SizeOf(Card));
    ArrayCard[I] := TempCard; //It Breaks Here...The Watch List: TempCard Inaccessible value
    End;
  FS.Free;
  End;

And I get a Exception EAccessViolation in module...

Then I also tried something like this: delphi Save and Load dynamic array It loads the array with the correct amount of items, but they are all empty or blank:

procedure TMainFrom.SaveCardsToFile;
var
  Stream: TStream;
  L: Integer;
  TmpPath: string;
  ICount: Integer;
  strm: TMemoryStream;

begin
  TmpPath:= TPath.Combine(TPath.GetDocumentsPath, 'Cards.bin');

  Stream:= TFileStream.Create(TmpPath, fmCreate);
  L:= Length(ArrayCard);
  Stream.WriteBuffer(L, SizeOf(L));
  Stream.WriteBuffer(Pointer(ArrayCard)^, L * SizeOf(Card));
  Stream.Free;
end;

procedure TMainFrom.LoadCardsFromFile;
var
  Stream: TStream;
  L: LongWord;
  TmpPath: string;

begin
  TmpPath:= TPath.Combine(TPath.GetDocumentsPath, 'Cards.bin');

  Stream:= TFileStream.Create(TmpPath, fmOpenRead);
  Stream.ReadBuffer(L, SizeOf(L));
  SetLength(ArrayCard, L);
  Stream.ReadBuffer(Pointer(ArrayCard)^, L * SizeOf(Card));
  Stream.Free;
end;

解决方案

With some help, I have managed to remake my code to work properly. Firstly I needed to make the string something like string[20] but that couldn't compile for android so I modified my record to use array of char like this:

type
  EventString= array [0..20] of Char;

  Card = record
    Name:  EventString; //string[20]
    Up,Right,Left,Down,Mark: Single;
    IDNumber: Integer;
    end; 

Then I modified my Saving/Loading procedures to use TFileStream instead of TStream and a for loop:

procedure TMainFrom.SaveCardsToFile;
var
  Stream: TFileStream;
  L: Integer;
  TmpPath: string;
  n: Integer;

begin
  TmpPath:= TPath.Combine(TPath.GetDocumentsPath, 'Cards.bin');
  Stream:= TFileStream.Create(TmpPath, fmCreate);
  L:= Length(ArrayCard)-1;
  for n:=0 to L do
  begin
    Stream.WriteBuffer(ArrayCard[n], SizeOf(Card)); //Saving
  end;
  Stream.Free;
end;

procedure TMainFrom.LoadCardsFromFile;
var
  Stream: TFileStream;
  L: LongWord;
  TmpPath: string;
  n: Integer;

begin
  TmpPath:= TPath.Combine(TPath.GetDocumentsPath, 'Cards.bin');
  Stream:= TFileStream.Create(TmpPath, fmOpenRead);
  SetLength(ArrayCard, Round(Stream.Size/SizeOf(Card)));
  L:= Length(ArrayCard)-1;
  for n:=0 to L do
  begin
    Stream.ReadBuffer(ArrayCard[n], SizeOf(Card)); //Loading
    ListCard.Items.Add(ArrayCard[n].Name); //Just adds card names to a listbox
  end;
  Stream.Free;

end;

And now it works just fine.

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