vb技巧7

自动出现动画、进度和确认的文件操作
使用以下的 API ， 得到与资源管理器相同的感觉！
Private Type SHFILEOPSTRUCT
hwnd As Long
wFunc As Long
pFrom As String
pTo As String
fFlags As Integer
fAnyOperationsAborted As Long
hNameMappings As Long
lpszProgressTitle As String '只有在 FOF_SIMPLEPROGRESS 时用
End Type

Private Declare Function SHFileOperation Lib _
"shell32.dll" Alias "SHFileOperationA" (lpFileOp _
As SHFILEOPSTRUCT) As Long

'wFunc 常数
'FO_COPY 把 pFrom 文件拷贝到 pTo。
Const FO_COPY = &H2
'FO_DELETE 删除 pFrom 中的文件（pTo 忽略）。
Const FO_DELETE = &H3
'FO_MOVE 把 pFrom 文件移动到 pTo。
Const FO_MOVE = &H1

'fFlag 常数
'FOF_ALLOWUNDO 允许 Undo 。
Const FOF_ALLOWUNDO = &H40
'FOF_NOCONFIRMATION 不显示系统确认对话框。
Const FOF_NOCONFIRMATION = &H10
'FOF_NOCONFIRMMKDIR 不提示是否新建目录。
Const FOF_NOCONFIRMMKDIR = &H200
'FOF_SILENT 不显示进度对话框
Const FOF_SILENT = &H4

例子：
Dim SHFileOp As SHFILEOPSTRUCT
' 删除
SHFileOp.wFunc = FO_DELETE
SHFileOp.pFrom = "c:\config.old" + Chr(0)
SHFileOp.fFlags = FOF_ALLOWUNDO + FOF_NOCONFIRMATION
Call SHFileOperation(SHFileOp)
' 删除多个文件
SHFileOp.wFunc = FO_DELETE
SHFileOp.pFrom = "c:\config.old" +Chr(0) + "c:\autoexec.old"+Chr(0)
SHFileOp.fFlags = FOF_ALLOWUNDO
Call SHFileOperation(SHFileOp)
' 拷贝
SHFileOp.wFunc = FO_COPY
SHFileOp.pFrom = "c:\t\*.*"
SHFileOp.pTo = "d:\t\*.*"
SHFileOp.fFlags = FOF_ALLOWUNDO + FOF_NOCONFIRMMKDIR
Call SHFileOperation(SHFileOp)
' 移动
SHFileOp.wFunc = FO_MOVE
SHFileOp.pFrom = "c:\config.old" + Chr(0)
SHFileOp.pTo = "d:\t"
SHFileOp.fFlags = FOF_ALLOWUNDO + FOF_NOCONFIRMATION
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快速建立目录
声明：
Private Type SECURITY_ATTRIBUTES
nLength As Long
lpSecurityDescriptor As Long
bInheritHandle As Long
End Type
Private Declare Function CreateDirectory Lib "kernel32" _
Alias "CreateDirectoryA" (ByVal lpPathName As String, _
lpSecurityAttributes As SECURITY_ATTRIBUTES) As Long
函数：
'Call CreateNewDirectory("c:\test\directory\vb\tips\")
Public Sub CreateNewDirectory(NewDirectory As String)
Dim sDirTest As String
Dim SecAttrib As SECURITY_ATTRIBUTES
Dim bSuccess As Boolean
Dim sPath As String
Dim iCounter As Integer
Dim sTempDir As String
iFlag = 0
sPath = NewDirectory
If Right(sPath, Len(sPath)) <> "\" Then
sPath = sPath & "\"
End If
iCounter = 1
Do Until InStr(iCounter, sPath, "\") = 0
iCounter = InStr(iCounter, sPath, "\")
sTempDir = Left(sPath, iCounter)
sDirTest = Dir(sTempDir)
iCounter = iCounter + 1
'create directory
SecAttrib.lpSecurityDescriptor = &O0
SecAttrib.bInheritHandle = False
SecAttrib.nLength = Len(SecAttrib)
bSuccess = CreateDirectory(sTempDir, SecAttrib)
Loop
End Sub
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开启文件属性窗口
声明：
Type SHELLEXECUTEINFO
cbSize As Long
fMask As Long
hwnd As Long
lpVerb As String
lpFile As String
lpParameters As String
lpDirectory As String
nShow As Long
hInstApp As Long
lpIDList As Long
lpClass As String
hkeyClass As Long
dwHotKey As Long
hIcon As Long
hProcess As Long
End Type

Public Const SEE_MASK_INVOKEIDLIST = &HC
Public Const SEE_MASK_NOCLOSEPROCESS = &H40
Public Const SEE_MASK_FLAG_NO_UI = &H400

Declare Function ShellExecuteEX Lib "shell32.dll" Alias _
"ShellExecuteEx" (SEI As SHELLEXECUTEINFO) As Long

代码：
' 使用： ShowProps("c:\command.com",Me.hWnd)
Public Sub ShowProps(FileName As String, OwnerhWnd As Long)
Dim SEI As SHELLEXECUTEINFO
Dim r As Long
With SEI
.cbSize = Len(SEI)
.fMask = SEE_MASK_NOCLOSEPROCESS Or _
SEE_MASK_INVOKEIDLIST Or SEE_MASK_FLAG_NO_UI
.hwnd = OwnerhWnd
.lpVerb = "properties"
.lpFile = FileName
.lpParameters = vbNullChar
.lpDirectory = vbNullChar
.nShow = 0
.hInstApp = 0
.lpIDList = 0
End With
r = ShellExecuteEX(SEI)
End Sub
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使用 WIN95 的选择目录对话框
声明：
Private Type BrowseInfo
hWndOwner As Long
pIDLRoot As Long
pszDisplayName As Long
lpszTitle As Long
ulFlags As Long
lpfnCallback As Long
lParam As Long
iImage As Long
End Type

Private Const BIF_RETURNONLYFSDIRS = 1
Private Const MAX_PATH = 260

Private Declare Sub CoTaskMemFree Lib "ole32.dll" (ByVal hMem As Long)
Private Declare Function lstrcat Lib "kernel32" Alias "lstrcatA" _
(ByVal lpString1 As String, ByVal lpString2 As String) As Long
Private Declare Function SHBrowseForFolder Lib "shell32" _
(lpbi As BrowseInfo) As Long
Private Declare Function SHGetPathFromIDList Lib "shell32" _
(ByVal pidList As Long, ByVal lpBuffer As String) As Long
函数：
Public Function BrowseForFolder(hWndOwner As Long, sPrompt As String) As String

Dim iNull As Integer
Dim lpIDList As Long
Dim lResult As Long
Dim sPath As String
Dim udtBI As BrowseInfo

With udtBI
.hWndOwner = hWndOwner
.lpszTitle = lstrcat(sPrompt, "")
.ulFlags = BIF_RETURNONLYFSDIRS
End With

lpIDList = SHBrowseForFolder(udtBI)
If lpIDList Then
sPath = String$(MAX_PATH, 0)
lResult = SHGetPathFromIDList(lpIDList, sPath)
Call CoTaskMemFree(lpIDList)
iNull = InStr(sPath, vbNullChar)
If iNull Then
sPath = Left$(sPath, iNull - 1)
End If
End If

BrowseForFolder = sPath

End Function
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移动文件到回收站
声明：
Public Type SHFILEOPSTRUCT
hwnd As Long
wFunc As Long
pFrom As String
pTo As String
fFlags As Integer
fAnyOperationsAborted As Long
hNameMappings As Long
lpszProgressTitle As Long
End Type

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

Public Const FO_DELETE = &H3
Public Const FOF_ALLOWUNDO = &H40
代码：
Dim SHop As SHFILEOPSTRUCT
Dim strFile as string

With SHop
.wFunc = FO_DELETE
.pFrom = strFile + Chr(0)
.fFlags = FOF_ALLOWUNDO
End With
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比较两个文件
Function CompFile(F1 as string, F2 as string) as boolean
Dim issame as boolean
Open F1 For Binary As #1
Open F2 For Binary As #2

issame = True
If LOF(1) <> LOF(2) Then
issame = False
Else
whole& = LOF(1) \ 10000 'number of whole 10,000 byte chunks
part& = LOF(1) Mod 10000 'remaining bytes at end of file
buffer1$ = String$(10000, 0)
buffer2$ = String$(10000, 0)
start& = 1
For x& = 1 To whole& 'this for-next loop will get 10,000
Get #1, start&, buffer1$ 'byte chunks at a time.
Get #2, start&, buffer2$
If buffer1$ <> buffer2$ Then
issame = False
Exit For
End If
start& = start& + 10000
Next
buffer1$ = String$(part&, 0)
buffer2$ = String$(part&, 0)
Get #1, start&, buffer1$ 'get the remaining bytes at the end
Get #2, start&, buffer2$ 'get the remaining bytes at the end
If buffer1$ <> buffer2$ Then
issame = False
End If
Close
CompFile = issame
End Function
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取得临时文件名
声明：
Public Const MAX_PATH = 260

Public Declare Function GetTempFileName Lib "kernel32" Alias "GetTempFileNameA" (ByVal lpszPath As String, ByVal lpPrefixString As String, ByVal wUnique As Long, ByVal lpTempFileName As String) As Long
Public Declare Function GetTempPath Lib "kernel32" Alias "GetTempPathA" (ByVal nBufferLength As Long, ByVal lpBuffer As String) As Long

代码：
Public Function GetTempFile() As String
Dim lngRet As Long
Dim strBuffer As String, strTempPath As String

'初始化 buffer
strBuffer = String$(MAX_PATH, 0)

'取得临时路径
lngRet = GetTempPath(Len(strBuffer), strBuffer)

'0 错误
If lngRet = 0 Then Exit Function

'去掉尾中的 null
strTempPath = Left$(strBuffer, lngRet)

'初始化 buffer
strBuffer = String$(MAX_PATH, 0)

'取得临时文件名
lngRet = GetTempFileName(strTempPath, "tmp", 0&, strBuffer)

If lngRet = 0 Then Exit Function

lngRet = InStr(1, strBuffer, Chr(0))
If lngRet > 0 Then
GetTempFile = Left$(strBuffer, lngRet - 1)
Else
GetTempFile = strBuffer
End If
End Function
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确定是 WINDOWS 的可执行文件
在文件的第 24 字节，如果为40h，就是 Windows 的可执行文件。

Function WinExe (ByVal Exe As String) As Integer
Dim fh As Integer
Dim t As String * 1
fh = FreeFile
Open Exe For Binary As #fh
Get fh, 25, t
Close #fh
WinExe = (Asc(t) = &H40&)
End Function
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建立多级目录
Sub CreateLongDir(sDrive As String, sDir As String)
Dim sBuild As String

While InStr(2, sDir, "\") > 1
sBuild = sBuild & left(sDir, InStr(2, sDir, "\") - 1)
sDir = Mid(sDir, InStr(2, sDir, "\"))
If Dir(sDrive & sBuild, 16) = "" Then
MkDir sDrive & sBuild
End If
Wend
End Sub
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取得文件的扩展名
Function GetExtension(Filename As String)
Dim PthPos, ExtPos As Integer

For i = Len(Filename) To 1 Step -1 ' Go from the Length of the filename, to the first character by 1.
If Mid(Filename, i, 1) = "." Then ' If the current position is '.' then...
ExtPos = i ' ...Change the ExtPos to the number.
For j = Len(Filename) To 1 Step -1 ' Do the Same...
If Mid(Filename, j, 1) = "\" Then ' ...but for '\'.
PthPos = j ' Change the PthPos to the number.
Exit For ' Since we found it, don't search any more.
End If
Next j
Exit For ' Since we found it, don't search any more.
End If
Next i

If PthPos > ExtPos Then
Exit Function ' No extension.
Else
If ExtPos = 0 Then Exit Function ' If there is not extension, then exit sub.
GetExtension = Mid(Filename, ExtPos + 1, Len(Filename) - ExtPos) 'Messagebox the Extension
End If

End Function
使用：
FileExt = GetExtension("c:\windows\vb\vb.exe")