用于记录类型的转发声明 [英] Forward declarations for record types

问题描述

标题中有这样的东西吗？我正在尝试这样做，部分转换为一个API结构，并且遇到一些我以前没有遇到过的东西：

  PFNReaderTranslatedDispatch = function （var msg：TMsg）：BOOL;标准
 PFNReaderScroll = function（var prmi：TReaderModeInfo; dx，dy：integer）：BOOL;标准
 TReaderModeInfo = record 
 cbSize：DWord; 
 hWnd：THandle; 
 fFlags：DWord; 
 prc：PRect; 
 pfnScroll：PFNReaderScroll; 
 fFlags2：PFNReaderTranslatedDispatch; 
 lParam：DWord; 
结束
 PReaderModeInfo = ^ TReaderModeInfo;知道德尔福的人会看到明显的问题。你会如何解决这个问题？
解决方案
我认为这是最简单的解决方案：
  PFNReaderTranslatedDispatch = function（var msg：TMsg）：BOOL;标准
 PReaderModeInfo = ^ TReaderModeInfo; 
 PFNReaderScroll = function（prmi：PReaderModeInfo; dx，dy：integer）：BOOL;标准
 TReaderModeInfo = record 
 cbSize：DWord; 
 hWnd：THandle; 
 fFlags：DWord; 
 prc：PRect; 
 pfnScroll：PFNReaderScroll; 
 fFlags2：PFNReaderTranslatedDispatch; 
 lParam：DWord; 
结束
  
的确，您可以清楚地重新发布一个 var 参数（by-value）指针参数。并且在 TReaderModeInfo 之前声明 PReaderModeInfo 没有问题。
 
Is there such a thing as in the title?  I'm trying to do this in part of converting an API structure, and run into something I haven't encountered before:
PFNReaderTranslatedDispatch = function(var msg: TMsg): BOOL; stdcall;
PFNReaderScroll = function(var prmi: TReaderModeInfo; dx, dy: integer): BOOL; stdcall;
TReaderModeInfo = record
  cbSize: DWord;
  hWnd: THandle;
  fFlags: DWord;
  prc: PRect;
  pfnScroll: PFNReaderScroll;
  fFlags2: PFNReaderTranslatedDispatch;
  lParam: DWord;
end;
PReaderModeInfo = ^TReaderModeInfo;
Those who know Delphi will see the obvious problem.  How would you work around this?
解决方案
I think this is the simplest solution:
PFNReaderTranslatedDispatch = function(var msg: TMsg): BOOL; stdcall;
PReaderModeInfo = ^TReaderModeInfo;
PFNReaderScroll = function(prmi: PReaderModeInfo; dx, dy: integer): BOOL; stdcall;
TReaderModeInfo = record
  cbSize: DWord;
  hWnd: THandle;
  fFlags: DWord;
  prc: PRect;
  pfnScroll: PFNReaderScroll;
  fFlags2: PFNReaderTranslatedDispatch;
  lParam: DWord;
end;
Indeed, you can clearly reaplce a var parameter by a (by-value) pointer parameter. And there is no problem declaring PReaderModeInfo before TReaderModeInfo.

                        
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