对TDictionary进行排序

Question

我对Generic Collections没有经验.我需要对TDictionary进行排序.

type TSearchResult = TPair<Integer,double>;

var
   target_results : TDictionary<Integer, double>;
   session_search_results : array[0..max_searches] of TArray<TSearchResult>;

我正在使用此代码进行排序

   session_search_results[session_search_id]:= target_results.ToArray;
   TArray.Sort<TSearchResult>(session_search_results[session_search_id],
                    TComparer<TSearchResult>.Construct(
                              function(const L, R: TSearchResult): Integer
                              begin
                                 Result := Round(R.Value - L.Value);
                              end
                    ));

为什么我会收到访问冲突？我究竟做错了什么？

补充:

如果我用数组遍历数组

 for i:= 0 to Length(session_search_results[session_search_id])-1 do
      MyDebug(IntToStr(session_search_results[session_search_id][i].Key)+' = value = '
            + FloatToStr(session_search_results[session_search_id][i].Value));

我得到一个输出:

Debug Output: ==>CoreSearchText: array length=8<== Process TestApp.exe (2536)
Debug Output: ==>100007 = value = 19,515<== Process TestApp.exe (2536)
Debug Output: ==>100003 = value = 2,4<== Process TestApp.exe (2536)
Debug Output: ==>100005 = value = 12<== Process TestApp.exe (2536)
Debug Output: ==>100008 = value = 2,4<== Process TestApp.exe (2536)
Debug Output: ==>100002 = value = 2,4<== Process TestApp.exe (2536)
Debug Output: ==>100004 = value = 2,4<== Process TestApp.exe (2536)
Debug Output: ==>100009 = value = 40,515<== Process TestApp.exe (2536)
Debug Output: ==>100001 = value = 15<== Process TestApp.exe (2536)

应用排序时,访问冲突会使应用程序崩溃.阵列似乎没问题.可能是什么原因？谢谢!

Answer 1

这似乎是XE中的codegen错误(也存在于XE2中),其中重新声明的通用记录和优化已打开.

该程序重现了该错误:

program Project1;

{$APPTYPE CONSOLE}
{$O+}

uses
  Generics.Collections,
  Generics.Defaults,
  SysUtils;

type
  TSearchResult = TPair<Integer, Integer>;

function Compare(const L, R: TSearchResult): Integer;
begin
  Result := R.Value - L.Value;
end;

var
  values: TArray<TSearchResult>;
begin
  try
    SetLength(values, 3);
    TArray.Sort<TSearchResult>(values, TComparer<TSearchResult>.Construct(Compare));
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
  Readln;
end.

我已将其报告为QC#106391.

一种可能的解决方案是将{$ O-}添加到包含对TArray <T> .Sort的调用的单元中.