CreateFile(filename, GENERIC_WRITE, FILE_SHARE_READ Or FILE_SHARE_WRITE, SA, CREATE_ALWAYS, 0, 0)
定义了一个sa结构,SA指向它
我第二个参数和第三个参数搞不懂 -.-
share mode 和access mode之间的关系是什么啊?
前面使用过的createfile函数没出错
这个跟前面的有什么关系呢?
3x!
定义了一个sa结构,SA指向它
我第二个参数和第三个参数搞不懂 -.-
share mode 和access mode之间的关系是什么啊?
前面使用过的createfile函数没出错
这个跟前面的有什么关系呢?
3x!
Alias "CreateFileA" _
(ByVal lpFileName As String, ByVal dwDesiredAccess As Long, _
ByVal dwShareMode As Long, ByVal lpSecurityAttributes As Long, _
ByVal dwCreationDisposition As Long, ByVal dwFlagsAndAttributes As Long, _
ByVal hTemplateFile As Long) As Long
【操作系统】
Win9X:Yes
WinNT:Yes【说明】 这是一个全功能的例程,可打开和创建文件、管道、邮槽、通信服务、设备以及控制台 【返回值】 Long,如执行成功,则返回文件句柄。INVALID_HANDLE_VALUE表示出错,会设置GetLastError。即使函数成功,但若文件存在,且指定了CREATE_ALWAYS
或 OPEN_ALWAYS,GetLastError也会设为ERROR_ALREADY_EXISTS 【其它】 打开一个通信端口时(如COM1),无论如何都要设置成
OPEN_EXISTING
这个函数代替了lOpen 和 lCreate函数,应该是我们的首选【参数表】
lpFileName ----- String,要打开的文件的名字 dwDesiredAccess - Long,如果为 GENERIC_READ
表示允许对设备进行读访问;如果为 GENERIC_WRITE
表示允许对设备进行写访问(可组合使用);如果为零,表示只允许获取与一个设备有关的信息 dwShareMode ---- Long,零表示不共享; FILE_SHARE_READ 和/或
FILE_SHARE_WRITE 表示允许对文件进行共享访问 lpSecurityAttributes - SECURITY_ATTRIBUTES,指向一个SECURITY_ATTRIBUTES结构的指针,定义了文件的安全特性(如果操作系统支持的话) dwCreationDisposition - Long,下述常数之一:
CREATE_NEW
创建文件;如文件存在则会出错
CREATE_ALWAYS
创建文件,会改写前一个文件
OPEN_EXISTING
文件必须已经存在。由设备提出要求
OPEN_ALWAYS
如文件不存在则创建它
TRUNCATE_EXISTING
讲现有文件缩短为零长度 dwFlagsAndAttributes - Long,一个或多个下述常数
FILE_ATTRIBUTE_ARCHIVE
标记归档属性
FILE_ATTRIBUTE_COMPRESSED
将文件标记为已压缩,或者标记为文件在目录中的默认压缩方式
FILE_ATTRIBUTE_NORMAL
默认属性
FILE_ATTRIBUTE_HIDDEN
隐藏文件或目录
FILE_ATTRIBUTE_READONLY
文件为只读
FILE_ATTRIBUTE_SYSTEM
文件为系统文件
FILE_FLAG_WRITE_THROUGH
操作系统不得推迟对文件的写操作
FILE_FLAG_OVERLAPPED
允许对文件进行重叠操作
FILE_FLAG_NO_BUFFERING
禁止对文件进行缓冲处理。文件只能写入磁盘卷的扇区块
FILE_FLAG_RANDOM_ACCESS
针对随机访问对文件缓冲进行优化
FILE_FLAG_SEQUENTIAL_SCAN
针对连续访问对文件缓冲进行优化
FILE_FLAG_DELETE_ON_CLOSE
关闭了上一次打开的句柄后,将文件删除。特别适合临时文件
也可在Windows NT下组合使用下述常数标记:
SECURITY_ANONYMOUS, SECURITY_IDENTIFICATION,
SECURITY_IMPERSONATION, SECURITY_DELEGATION, SECURITY_CONTEXT_TRACKING,
SECURITY_EFFECTIVE_ONLY
hTemplateFile -- Long,如果不为零,则指定一个文件句柄。新文件将从这个文件中复制扩展属性
'This program needs a Dialog box, named CDBox1
' (To add the Common Dialog Box to your tools menu, go to Project->Components (or press CTRL-T)
' and select Microsoft Common Dialog control)
Private Type FILETIME
dwLowDateTime As Long
dwHighDateTime As Long
End Type
Private Type SHFILEOPSTRUCT
hWnd As Long
wFunc As Long
pFrom As String
pTo As String
fFlags As Integer
fAborted As Boolean
hNameMaps As Long
sProgress As String
End Type
Private Type SYSTEMTIME
wYear As Integer
wMonth As Integer
wDayOfWeek As Integer
wDay As Integer
wHour As Integer
wMinute As Integer
wSecond As Integer
wMilliseconds As Integer
End Type
Private Const GENERIC_WRITE = &H40000000
Private Const OPEN_EXISTING = 3
Private Const FILE_SHARE_READ = &H1
Private Const FILE_SHARE_WRITE = &H2
Private Const FO_DELETE = &H3
Private Declare Function CopyFile Lib "kernel32" Alias "CopyFileA" (ByVal lpExistingFileName As String, ByVal lpNewFileName As String, ByVal bFailIfExists As Long) As Long
Private Declare Function CreateDirectory Lib "kernel32" Alias "CreateDirectoryA" (ByVal lpPathName As String, lpSecurityAttributes As Long) As Long
Private Declare Function DeleteFile Lib "kernel32" Alias "DeleteFileA" (ByVal lpFileName As String) As Long
Private Declare Function GetFileSize Lib "kernel32" (ByVal hFile As Long, lpFileSizeHigh As Long) As Long
Private Declare Function GetFileTime Lib "kernel32" (ByVal hFile As Long, lpCreationTime As FILETIME, lpLastAccessTime As FILETIME, lpLastWriteTime As FILETIME) As Long
Private Declare Function MoveFile Lib "kernel32" Alias "MoveFileA" (ByVal lpExistingFileName As String, ByVal lpNewFileName As String) As Long
Private Declare Function CreateFile Lib "kernel32" Alias "CreateFileA" (ByVal lpFileName As String, ByVal dwDesiredAccess As Long, ByVal dwShareMode As Long, lpSecurityAttributes As Long, ByVal dwCreationDisposition As Long, ByVal dwFlagsAndAttributes As Long, ByVal hTemplateFile As Long) As Long
Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long
Private Declare Function SHFileOperation Lib "shell32.dll" Alias "SHFileOperationA" (lpFileOp As SHFILEOPSTRUCT) As Long
Private Declare Function FileTimeToSystemTime Lib "kernel32" (lpFileTime As FILETIME, lpSystemTime As SYSTEMTIME) As Long
Private Declare Function FileTimeToLocalFileTime Lib "kernel32" (lpFileTime As FILETIME, lpLocalFileTime As FILETIME) As Long
Private Sub Form_Load()
'KPD-Team 1998
'URL: http://www.allapi.net/
'E-Mail: [email protected]
Dim lngHandle As Long, SHDirOp As SHFILEOPSTRUCT, lngLong As Long
Dim Ft1 As FILETIME, Ft2 As FILETIME, SysTime As SYSTEMTIME
'Set the dialog's title
CDBox.DialogTitle = "Choose a file ..."
'Raise an error when the user pressed cancel
CDBox.CancelError = True
'Show the 'Open File'-dialog
CDBox.ShowOpen
'Create a new directory
CreateDirectory "C:\KPD-Team", ByVal &H0
'Copy the selected file to our new directory
CopyFile CDBox.filename, "C:\KPD-Team\" + CDBox.FileTitle, 0
'Rename the file
MoveFile "C:\KPD-Team\" + CDBox.FileTitle, "C:\KPD-Team\test.kpd"
'Open the file
lngHandle = CreateFile("C:\KPD-Team\test.kpd", GENERIC_WRITE, FILE_SHARE_READ Or FILE_SHARE_WRITE, ByVal 0&, OPEN_EXISTING, 0, 0)
'Get the file's size
MsgBox "The size of the selected file is" + Str$(GetFileSize(lngHandle, lngLong)) + " bytes."
'Get the fil's time
GetFileTime lngHandle, Ft1, Ft1, Ft2
'Convert the file time to the local file time
FileTimeToLocalFileTime Ft2, Ft1
'Convert the file time to system file time
FileTimeToSystemTime Ft1, SysTime
MsgBox "The selected file was created on" + Str$(SysTime.wMonth) + "/" + LTrim(Str$(SysTime.wDay)) + "/" + LTrim(Str$(SysTime.wYear))
'Close the file
CloseHandle lngHandle
'Delete the file
DeleteFile "C:\KPD-Team\test.kpd"
With SHDirOp
.wFunc = FO_DELETE
.pFrom = "C:\KPD-Team"
End With
'Delete the directory
SHFileOperation SHDirOp
End
End Sub
所以一开始定义了一个 SA结构,如下:
<StructLayout(LayoutKind.Sequential)> Public Structure SECURITY_ATTRIBUTES
Private nLength As Integer
Private lpSecurityDescriptor As Integer
Private bInheritHandle As Integer
End Structure
然后 dim sa as SECURITY_ATTRIBUTES
当时我也有一点疑惑,因为这里并没有对里面每一个成员赋值
不过在其他用这个没问题的,就没有深究
这个参数和access mode,share mode 有什么关系?
表示允许对设备进行读访问;如果为 GENERIC_WRITE
表示允许对设备进行写访问(可组合使用);如果为零,表示只允许获取与一个设备有关的信息
就是他们之间的关系搞不清楚
msdn里面有个表,就是讲access跟share的关系的,看不大懂 -.-
还有可能跟SA有关,跟前面已经用过了的createfile函数有关
蛮复杂的样子
只是这样不能覆盖了