windows - 如何使 WinHttpCrackUrl 在 64 位中工作

Question

我有使用 WinHttp 的 Visual Basic for Applications 代码，并且可以与在 32 位 Windows XP 上运行的 32 位 Office 2010 完美配合。相同的代码无法在 64 位 Windows 8 上的 64 位 Office 2013 上正常运行，即使它可以正常编译。

问题是 WinHttpCrackUrl() 在 Windows 8 上返回错误 87“参数不正确”。

我已经仔细检查并三重检查了代码中所有指针是否在适当的地方声明为 LongPtr。我做错了什么？

以下代码在 32 位 Excel/Windows 上运行良好，但在 64 位 Excel/Windows 上运行失败:

Private Type URL_COMPONENTS
    dwStructSize      As Long
    lpszScheme        As LongPtr
    dwSchemeLength    As Long
    nScheme           As Long
    lpszHostName      As LongPtr
    dwHostNameLength  As Long
    nPort             As Long
    lpszUserName      As LongPtr
    dwUserNameLength  As Long
    lpszPassword      As LongPtr
    dwPasswordLength  As Long
    lpszUrlPath       As LongPtr
    dwUrlPathLength   As Long
    lpszExtraInfo     As LongPtr
    dwExtraInfoLength As Long
End Type

Private Declare PtrSafe Function WinHttpCrackUrl Lib "WinHTTP" ( _
    ByVal pwszUrl As LongPtr, _
    ByVal dwUrlLength As Long, _
    ByVal dwFlags As Long, _
    ByRef lpUrlComponents As URL_COMPONENTS) As Long

Sub Test()
    Dim result as Long
    Dim URLComp As URL_COMPONENTS
    Dim mURL as String
    mURL = "http://www.stackoverflow.com" & vbNullChar

    With URLComp
        .dwStructSize = Len(URLComp)
        .dwHostNameLength = -1
        .dwSchemeLength = -1
        .dwUrlPathLength = -1
    End With

    result = WinHttpCrackUrl(StrPtr(mURL), 0, 0, URLComp)

    ' Prints 1 on 32-bit Excel/Windows (indicating success)
    ' Prints 0 on 64-bit Excel/Windows (indicating failure)
    Debug.Print result

    ' Prints 87 on 64-bit Excel/Windows ("The parameter is incorrect.")
    Debug.Print err.LastDllError
End Sub

Answer 1

struct 在 C++ 代码中是对齐的，但 VBA 结构是打包的。在 32 位中，对于您的结构，这无关紧要，因为所有成员都对齐 4。但在 64 位中，指针需要 8 字节对齐，并且结构有一些额外的填充。像这样输入:

Private Type URL_COMPONENTS
    dwStructSize      As Long
    padding1          As Long
    lpszScheme        As LongPtr
    dwSchemeLength    As Long
    nScheme           As Long
    lpszHostName      As LongPtr
    dwHostNameLength  As Long
    nPort             As Long
    lpszUserName      As LongPtr
    dwUserNameLength  As Long
    padding2          As Long
    lpszPassword      As LongPtr
    dwPasswordLength  As Long
    padding3          As Long
    lpszUrlPath       As LongPtr
    dwUrlPathLength   As Long
    padding4          As Long
    lpszExtraInfo     As LongPtr
    dwExtraInfoLength As Long
    padding5          As Long
End Type

我猜你会想要一些条件编译来切换更好的 32 位和 64 位版本，但我必须承认不知道如何用 VBA 做到这一点。