Question

我有一些我以前从未见过的东西。调试时未在“局部变量”窗口中显示的局部变量。我正在附加图片。 WHY U NO SHOWN THERE?

如您所见，我在代码中使用变量，并在调试时禁用优化。但我也使用泛型和匿名方法，我不是专家。有问题的过程的代码是这样的（该过程的作用是按顺序排列第一个数组ArrayNomes，ArrayValores按第一个数组中字符串的长度排序）：

  procedure OrdenarArrays(var ArrayNomes, ArrayValores: array of string; var ArrayIndices: array of Integer);
  var
    Comparer: IComparer<Integer>;
    I: Integer;
    tmpNomesCampos, tmpValoresCampos: array of String;
  begin

    SetLength(tmpNomesCampos,   cdsCadastro.FieldCount);
    SetLength(tmpValoresCampos, cdsCadastro.FieldCount);

    //Carregar os NomesCampos para serem usados na comparação
    for I := 0 to High(arrayIndices) do
    begin
      tmpNomesCampos[I] := ArrayNomes[I];
    end;

    { Cria novo delegatedcomparer. Ele permite o uso de um callback para comparar os arrays}
    Comparer := TDelegatedComparer<Integer>.Create(
      { TComparison<Integer> }
      function(const Left, Right: Integer): Integer
      begin
        {colocar em ordem decrescente de acordo com o tamanho do nome do campo}
//        Result := Left - Right;
        Result := -(Length(tmpNomesCampos[Left]) - Length(tmpNomesCampos[Right]));
      end);

    { Ordena o Array base }
    TArray.Sort<Integer>(arrayIndices, Comparer);

    //Reordenar os NomesCampos de acordo com o array IndicesCampos
    for I := 0 to High(arrayIndices) do
    begin
      tmpNomesCampos[I]   := ArrayNomes[arrayIndices[I]];
      tmpValoresCampos[I] := ArrayValores[arrayIndices[I]];
    end;

    //Salvar nos arrays definitivos;
    for I := 0 to High(arrayIndices) do
    begin
      ArrayNomes[I]   := tmpNomesCampos[I];
      ArrayValores[I] := tmpValoresCampos[I];
    end;

  end;

此变量是否显示错误？这是一个已知的bug吗？或者它是否是使用我不知道的泛型和匿名方法的功能？

系统：Windows 7 64位/ Delphi XE（最新更新）

更新：将代码更改为下面的简化控制台版本。这可能有助于任何想要在他的Delphi版本中测试的人。注意：它不会填充原始数组，因为没有必要显示问题;

program Project1;


{$APPTYPE CONSOLE}

uses
  SysUtils, Generics.Collections, Generics.Defaults;

  procedure OrdenarArrays(var ArrayNomes, ArrayValores: array of string; var ArrayIndices: array of Integer);
  var
    Comparer: IComparer<Integer>;
    I: Integer;
    tmpNomesCampos, tmpValoresCampos: array of String;
  begin

    SetLength(tmpNomesCampos,   Length(arrayIndices));
    SetLength(tmpValoresCampos, Length(arrayIndices));

    //Carregar os NomesCampos para serem usados na comparação
    for I := 0 to High(arrayIndices) do
    begin
      tmpNomesCampos[I] := ArrayNomes[I];
    end;

    { Cria novo delegatedcomparer. Ele permite o uso de um callback para comparar os arrays}
    Comparer := TDelegatedComparer<Integer>.Create(
      { TComparison<Integer> }
      function(const Left, Right: Integer): Integer
      begin
        {colocar em ordem decrescente de acordo com o tamanho do nome do campo}
  //        Result := Left - Right;
        Result := -(Length(tmpNomesCampos[Left]) - Length(tmpNomesCampos[Right]));
      end);

    { Ordena o Array base }
    TArray.Sort<Integer>(arrayIndices, Comparer);

    //Reordenar os NomesCampos de acordo com o array IndicesCampos
    for I := 0 to High(arrayIndices) do
    begin
      tmpNomesCampos[I]   := ArrayNomes[arrayIndices[I]];
      tmpValoresCampos[I] := ArrayValores[arrayIndices[I]];
    end;

    //Salvar nos arrays definitivos;
    for I := 0 to High(arrayIndices) do
    begin
      ArrayNomes[I]   := tmpNomesCampos[I];
      ArrayValores[I] := tmpValoresCampos[I];
    end;

  end;

var
  NomesCampos, ValoresCampos: array of String;
  IndicesCampos: array of Integer;
  I: Integer;
begin
  try

    SetLength(NomesCampos,   42);
    SetLength(ValoresCampos, 42);
    SetLength(IndicesCampos, 42);

//    for I := 0 to 41 do

    OrdenarArrays(NomesCampos, ValoresCampos, IndicesCampos);

    Readln;
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
end.

Answer 1

这是XE5中仍然存在的调试器/ IDE错误。正如您所怀疑的，问题在于使用匿名方法。关键是是否捕获变量。捕获变量时，该变量不会显示在“局部”窗口中。这是我能编制的最短的SSCCE：

{$APPTYPE CONSOLE}

uses
  System.SysUtils;

procedure Foo1;
var
  func: TFunc<Integer>;
  val: Integer;
begin
  val := 666;
  func :=
    function: Integer
    begin
      Result := val;
    end;
end;

procedure Foo2;
var
  func: TFunc<Integer>;
  val: Integer;
begin
  val := 666;
  func :=
    function: Integer
    begin
      Result := 666;
    end;
end;

begin
  Foo1;
  Foo2;
  Readln;
end.

在调试器中，Foo1.val未显示在“本地”窗口中。但Foo2.val确实如此。

QC#121821

Answer 2

不是问题的答案，而是关于如何以更简单的方式编写例程的建议（至少如果我理解它应该做什么）

procedure OrderArrays(var ArrayNameValuePairs: array of TPair<string, string>);
begin
  TArray.Sort<TPair<string, string>>(ArrayNameValuePairs,
    TComparer<TPair<string, string>>.Construct(
      function(const Left, Right: TPair<string, string>): Integer
      begin
        Result := Length(Right.Key) - Length(Left.Key);
      end));
end;

正如您所看到的，我将名称和值组合在一起，因为它们显然属于一体。这使得对这个组合数组的排序变得更加容易，因为您不必对包含indizes的第三个数组进行排序以重新排序两个原始数组。

动态数组变量未显示在“局部变量”调试窗口中

2 个答案: