如何使用文件复制对话框？

　　Visual Basic 提供了过时的FileCopy语句.问题是使用该函数时并不显示文件复制对话框,也就是说,当拷贝一个大文件时,用户看不到Windows的标准文件复制对话框,无法从进度条上判断当前复制的进度.那么,如何做到这一点呢?请看下面:

Public Type SHFILEOPSTRUCT
hWnd As Long
wFunc As Long
pFrom As String
pTo As String
fFlags As Integer
fAnyOperationsAborted As Boolean
hNameMappings As Long
lpszProgressTitle As String
End Type

Public Declare Function SHFileOperation Lib "shell32.dll" Alias _
"SHFileOperationA" (lpFileOp As SHFILEOPSTRUCT) As Long
Public Const FO_COPY =