请问是{$IFDEF NT5}什么意思？谢谢！(50分)

我在单元中调用了一个winAPI函数：'CryptEnumProviders'，出现错误如下：<br>[Error] Unit1.pas(203): Undeclared identifier: 'CryptEnumProviders'<br>谁能帮助我一下？谢谢！

这是你标题的问题。解答如下：<br><br>procedure TForm1.Button1Click(Sender: TObject);<br>begin<br>{$DEFINE MyDefine}<br>{$IFDEF MyDefine}<br>&nbsp; ShowMessage('Have MyDefine');<br>{$ELSE}<br>&nbsp; ShowMessage('Not Have MyDefine');<br>{$ENDIF}<br><br>{$UNDEF MyDefine}<br><br>{$IFNDEF MyDefine}<br>&nbsp; ShowMessage('Not Have MyDefine');<br>{$ENDIF}<br><br>end;<br>

把那单元贴出来。

条件编译

有这个WinApi吗？

{$IFDEF NT5}用来指示编译器符合条件才编译<br>CryptEnumProviders在Delphi中没有声明<br>声明如下：<br>interface<br>{$IFDEF UNICODE}<br>function CryptEnumProviders(dwIndex: DWORD; pdwReserved: LPDWORD; dwFlags: DWORD;<br>&nbsp; var pdwProvType: DWORD; pszProvName: LPWSTR; var pcbProvName: DWORD): BOOL; stdcall;<br>{$EXTERNALSYM CryptEnumProviders}<br>{$ELSE}<br>function CryptEnumProviders(dwIndex: DWORD; pdwReserved: LPDWORD; dwFlags: DWORD;<br>&nbsp; var pdwProvType: DWORD; pszProvName: LPSTR; var pcbProvName: DWORD): BOOL; stdcall;<br>{$EXTERNALSYM CryptEnumProviders}<br>{$ENDIF}<br><br><br>implementation<br>{$IFDEF UNICODE}<br>function CryptEnumProviders; external advapi32 name 'CryptEnumProvidersW';<br>{$ELSE}<br>function CryptEnumProviders; external advapi32 name 'CryptEnumProvidersA';<br>{$ENDIF}<br><br>

请问如何将函数：CryptGetProvParam(hProv,<br> &nbsp; &nbsp; &nbsp; PP_ENUMALGS, <br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; pbData, <br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;@cbData,<br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;dwFlags);<br>得到的pbdata赋给一个数组。（pbdata是pbyte类型）。数组名为szName.<br>谢谢！

end.

接受答案了.