VB通用对话框

[pfjuifv]

我用API做了一个通用对话框可是怎么才能设置打开文件的时候为缩略图模式也就是可以预览图片。
' FileOpen 类实现 =========================================================
Public Function ShowOpen() As Boolean
Dim fName As String, sName As String, OfName As OPENFILENAME

OfName.lStructSize = Len(OfName)
OfName.hwndOwner = m_lngHwnd
OfName.hInstance = m_lngInstance

OfName.lpstrInitialDir = m_strInitDir
OfName.lpstrFile = m_strFileName & Space(32767 - Lstrlen(m_strFileName)) & Chr(0)
OfName.nMaxFile = 32768
OfName.lpstrFilter = m_strFilter
OfName.lpstrFileTitle = Space(32767) & Chr(0)
OfName.nMaxFileTitle = 32768
OfName.lpstrTitle = m_strDialogTitle
OfName.flags = m_lngFlags
If GetOpenFileName(OfName) Then
m_strFileName = OfName.lpstrFile
m_strFileTitle = OfName.lpstrFileTitle
ShowOpen = True
Else
ShowOpen = False
End If
这是其中一段代码。