Getting type of record field with RTTI fails for static arrays

问题

I am trying to get types for record fields in order to create correct comparer (as general solution for any/almost any record type). I can't find type information for static arrays:

  TArrFieldTest = record
    a: string;
    b: array[0..3] of byte;
  end;

procedure Test;
var
  rttiContext: TRttiContext;
  rttiType: TRttiType;
  rttiFields: TArray<TRttiField>;
begin
  rttiType := rttiContext.GetType(TypeInfo(TArrFieldTest));
  rttiFields := rttiType.GetFields;
  Assert(rttiFields[0].FieldType<>nil); // it's ok
  Assert(rttiFields[1].FieldType<>nil); // fail here!
end;

FieldType is nil for static array of any type. Any ideas what is wrong here? Or maybe there is easier way to create comparer for records to be used with TArray/TDictionary etc?

回答1:

You need to declare a type in order to have RTTI available. For example:

type
  TMyStaticArrayOfByte = array[0..3] of byte;

  TArrFieldTest = record
    a: string;
    b: TMyStaticArrayOfByte;
  end;

来源：https://stackoverflow.com/questions/34747007/getting-type-of-record-field-with-rtti-fails-for-static-arrays