uses引用了Classes,其中有这么个定义:
type
  PObjectInstance = ^TObjectInstance;
  TObjectInstance = packed record
    Code: Byte;
    Offset: Integer;
    case Integer of
      0: (Next: PObjectInstance);
      1: (FMethod: TWndMethod);
  end;

type
  PInstanceBlock = ^TInstanceBlock;
  TInstanceBlock = packed record
    Next: PInstanceBlock;
    Code: array[1..2] of Byte;
    WndProcPtr: Pointer;
    Instances: array[0..InstanceCount] of TObjectInstance;
  end;

var
  InstBlockList: PInstanceBlock;
  InstFreeList: PObjectInstance;


我代码中想要定义InstBlockLst:PInstanceBlock ,但是编译时总是提示"E2003 Undeclared identifier: 'PInstanceBlock'"错误,着急迷忙中,还请高手指教