vba - DragQueryFile 总是返回 0

Question

我尝试在 PowerPoint 中使用 VBA 访问剪贴板中的文件，但 DragQueryFile 始终返回 0。

这里我的代码被剪掉了

Private Declare PtrSafe Function IsClipboardFormatAvailable Lib "user32" (ByVal uFormat As Long) As Long
Private Declare PtrSafe Function GetClipboardData Lib "user32" (ByVal uFormat As Long) As Long
Private Declare PtrSafe Function OpenClipboard Lib "user32" ( ByVal hwnd As Long) As Long
Private Declare PtrSafe Function DragQueryFile Lib "shell32.dll" Alias "DragQueryFileA" ( ByVal HDROP As Long, ByVal UINT As Long, ByVal lpStr As String, ByVal ch As Long) As Long
Private Declare PtrSafe Function CloseClipboard Lib "user32" () As Long
Private Const CF_HDROP As Long = 15

Private Sub test_clipboard()
Dim nHandle As Long
If IsClipboardFormatAvailable(CF_HDROP) > 0 Then
    If OpenClipboard(0) <> 0 Then
        nHandle = GetClipboardData(CF_HDROP)
        If nHandle <> 0 Then        
            ' Query number of files in clipboard -> returns always 0
            Debug.Print CStr(DragQueryFile(nHandle, GetNumOfFiles, vbNullString, 0)) 
        End If
        CloseClipboard
    End If
End If

End sub

我使用的是 Windows 10 和 Office 2013。

C# 有一个类似的帖子 ( DragQueryFile returns 0 when I try to get file count? )，但我已经将 OpenClipboard 称为 CloseClipboard。

感谢任何帮助。

Answer 1

我根据 tmp_hallenser 的评论得到了它，但我认为将其布局得更清楚会更好。

应该改变这两个函数定义:

Private Declare PtrSafe Function GetClipboardData Lib "user32" (ByVal uFormat As Long) As LongPtr
Private Declare PtrSafe Function DragQueryFile Lib "shell32.dll" Alias "DragQueryFileA" ( ByVal HDROP As LongPtr, ByVal UINT As Long, ByVal lpStr As String, ByVal ch As Long) As Long

这是必要的，因为 HDROP 是一个内存地址，因此会根据系统的不同而有不同的大小。

LongPtr 类型 will always be the appropriate size .