delphi – 如果我自己导入了SHParseDisplayName,为什么SHParseDisplayName会给出访问冲突？

我试图在Delphi中获取pidl形式的路径时获得访问冲突,并且返回的pidl为nil.这是我的代码：

type
  // TParseDisplayName = function(pszPath: PChar; pbc: pointer; var pidl: PItemIDList; sfgaoIn: LongWord; var psfgaoOut: LongWord): LongInt;
  TParseDisplayName = function(pszPath: PWideChar; pbc: IBindCtx; var pidl: PItemIDList; sfgaoIn: ULong; var psfgaoOut: ULong): HResult;

var
  SHParseDisplayName: TParseDisplayName;
  SHELL32DLLHandle : THandle;

procedure test();
var
  ws : WideString;
  tmpLongWord: ULong;
  lpItemID: PItemIDList;
begin
  //ws := 'Mes documents';

  CoInitialize(nil);

  // path to test
  ws := 'C:\inetsdk\Nouveau Document WordPad.doc';

  if (SHParseDisplayName(PWideChar(ws),nil,lpItemID,tmpLongWord) = S_OK) then
    if not assigned(lpItemID) then      
      s := SysErrorMessage(getLastError);

  CoUnInitialize();
end;

initialization
  SHELL32DLLHandle  := LoadLibraryW('shell32.dll');

  @SHParseDisplayName := GetProcAddress(SHELL32DLLHandle,'SHParseDisplayName');

解决方法

TParseDisplayName的声明省略了调用约定.你需要包括stdcall.

TParseDisplayName = function(pszPath: PWideChar; pbc: IBindCtx; 
  var pidl: PItemIDList; sfgaoIn: ULong; var psfgaoOut: ULong): HResult; stdcall;

如果未指定调用约定,则使用默认调用约定.默认调用约定是register.这对于参数传递和清理具有不同的语义,这导致您遇到的运行时错误类型.实际上所有的Windows API函数都使用了stdcall.