FindFirstFileA (ANSI) works as it should, while FindFirstFileW (Unicode) not.
The Wide version always return -1 (INVALID_HANDLE_VALUE), but why?
'Declarations:
Option Explicit
Private Const MAX_PATH As Long = 260
Private Const ALTERNATE As Long = 14
Private Const INVALID_HANDLE_VALUE As Long = -1
Private Type FILETIME
dwLowDateTime As Long
dwHighDateTime As Long
End Type
Private Type WIN32_FIND_DATA
dwFileAttributes As Long
ftCreationTime As FILETIME
ftLastAccessTime As FILETIME
ftLastWriteTime As FILETIME
nFileSizeHigh As Long
nFileSizeLow As Long
dwReserved0 As Long
dwReserved1 As Long
cFileName As String * MAX_PATH
cAlternate As String * ALTERNATE
End Type
Private Declare Function FindFirstFileW Lib "kernel32" _
(ByVal lpFileName As String, _
ByRef lpFindFileData As WIN32_FIND_DATA) As Long
Private Declare Function FindFirstFileA Lib "kernel32" _
(ByVal lpFileName As String, _
ByRef lpFindFileData As WIN32_FIND_DATA) As Long
Private Declare Function FindClose Lib "kernel32" _
(ByVal hFindFile As Long) As Long
Public Declare Function GetLastError Lib "kernel32" () As Integer
'Test Functions:
Public Function TestA(ByVal sf As String) As Long
If Len(sf) < 3 Then Exit Function
Dim wfd As WIN32_FIND_DATA
TestA = FindFirstFileA(sf, wfd)
'Debug.Print "AE:" & GetLastError()
If TestA <> INVALID_HANDLE_VALUE Then FindClose TestA
End Function
Public Function TestW(ByVal sf As String) As Long
If Len(sf) < 3 Then Exit Function
Dim wfd As WIN32_FIND_DATA
TestW = FindFirstFileW(sf, wfd)
'Debug.Print "WE:" & GetLastError()
If TestW <> INVALID_HANDLE_VALUE Then FindClose TestW
End Function
'Example test
Private Sub Command1_Click()
Dim sDir As String
sDir = "C:\new"
MsgBox "A: " & TestA(sDir) & vbCrLf _
& "W: " & TestW(sDir)
End Sub
P.S. Thanks to Carey Gregory, but I still need a bit of help to translate Wide version. What's the equivalent of C/C++ WCHAR in VB6?
//WinBase.h
typedef struct _WIN32_FIND_DATAA {
DWORD dwFileAttributes;
FILETIME ftCreationTime;
FILETIME ftLastAccessTime;
FILETIME ftLastWriteTime;
DWORD nFileSizeHigh;
DWORD nFileSizeLow;
DWORD dwReserved0;
DWORD dwReserved1;
CHAR cFileName[ MAX_PATH ];
CHAR cAlternateFileName[ 14 ];
#ifdef _MAC
DWORD dwFileType;
DWORD dwCreatorType;
WORD wFinderFlags;
#endif
} WIN32_FIND_DATAA, *PWIN32_FIND_DATAA, *LPWIN32_FIND_DATAA;
typedef struct _WIN32_FIND_DATAW {
DWORD dwFileAttributes;
FILETIME ftCreationTime;
FILETIME ftLastAccessTime;
FILETIME ftLastWriteTime;
DWORD nFileSizeHigh;
DWORD nFileSizeLow;
DWORD dwReserved0;
DWORD dwReserved1;
WCHAR cFileName[ MAX_PATH ]; //WCHAR in VB6?
WCHAR cAlternateFileName[ 14 ]; //WCHAR in VB6?
#ifdef _MAC
DWORD dwFileType;
DWORD dwCreatorType;
WORD wFinderFlags;
#endif
} WIN32_FIND_DATAW, *PWIN32_FIND_DATAW, *LPWIN32_FIND_DATAW;
WIN32_FIND_DATA has two versions just like the functions that use them: an ANSI version and a Unicode version. You need to define WIN32_FIND_DATAA and WIN32_FIND_DATAW and use them appropriately with the 'A' and 'W' functions.
Well, after re-reading this article I found my mistake. It's not about separate WIN32_FIND_DATAW type, but need to declare FindFirstFileW arguments as Long and ByVal.
Private Declare Function FindFirstFileW Lib "kernel32" _
(ByVal lpFileName As Long, _
ByVal lpFindFileData As Long) As Long
And also need to call them with StrPtr and VarPtr.
TestW = FindFirstFileW(StrPtr(sf), VarPtr(wfd))
Related
Currently, my console application can return Integer values from the console application via the kernel32 function ExitProcess.
Public Declare Sub ExitProcess Lib "kernel32" (ByVal uExitCode As Long)
How do I return string values from the console application to the batch file?
I want to return string values like Successfully transformed 100 batches... etc.
On most platforms (and also in Windows) process exit codes are integer values, but you could write string data to the standard output stream by using the GetStdHandle and WriteFile functions.
Update As requested, I´ll serve you an example.
First, you´ll need to import some more Windows functions and define the required constants. In addition to the before-mentioned GetStdHandle and WriteFile methods, the AttachConsole and FreeConsole methods are also required.
Private Const ATTACH_PARENT_PROCESS As Long = -1
Private Declare Function AttachConsole Lib "Kernel32" ( _
ByVal dwProcessId As Long) As Long
Private Declare Function FreeConsole Lib "Kernel32" () As Long
Private Const STD_OUTPUT_HANDLE As Long = -11&
Private Declare Function GetStdHandle Lib "Kernel32" ( _
ByVal nStdHandle As Long) As Long
Private Declare Function WriteFile Lib "Kernel32" ( _
ByVal hFile As Long, _
ByVal lpBuffer As String, _
ByVal nNumberOfBytesToWrite As Long, _
ByRef lpNumberOfBytesWritten As Long, _
lpOverlapped As Any) As Long
In my sample project, I just added a Module and defined a Sub Main method - this serves as the entry point for the app. Please notice, that you don´t get any output from the app when running it from the VB6 IDE debugger. You´ll need to compile it, and run it from a terminal window (for instance cmd.exe).
The first thing to do is to attach to the console of the parent process (which is the console of the terminal window). Otherwise, the GetStdHandle method will return zero.
Dim handle As Long
AttachConsole (ATTACH_PARENT_PROCESS)
handle = GetStdHandle(STD_OUTPUT_HANDLE)
Once the console handle is obtained, the WriteFile method can be used to print text to the console.
Dim s As String
Dim numberOfBytesWritten As Long
s = "Hello World."
WriteFile handle, s, Len(s), numberOfBytesWritten, ByVal 0&
Before finally calling ExitProcess, the FreeConsole method is used to detach the process from the parent console.
I have Visual Basic for Applications code that uses WinHttp and works flawlessly with 32-bit Office 2010 running on 32-bit Windows XP. The same code fails to run properly on 64-bit Office 2013 on 64-bit Windows 8, even though it compiles fine.
The problem is that WinHttpCrackUrl() returns an error 87 "The parameter is incorrect" on Windows 8.
I have double-checked and triple-checked that all pointers are declared as LongPtr in the code where appropriate. What am I doing wrong?
Here is the code that runs fine on 32-bit Excel/Windows, but fails to run on 64-bit Excel/Windows:
Private Type URL_COMPONENTS
dwStructSize As Long
lpszScheme As LongPtr
dwSchemeLength As Long
nScheme As Long
lpszHostName As LongPtr
dwHostNameLength As Long
nPort As Long
lpszUserName As LongPtr
dwUserNameLength As Long
lpszPassword As LongPtr
dwPasswordLength As Long
lpszUrlPath As LongPtr
dwUrlPathLength As Long
lpszExtraInfo As LongPtr
dwExtraInfoLength As Long
End Type
Private Declare PtrSafe Function WinHttpCrackUrl Lib "WinHTTP" ( _
ByVal pwszUrl As LongPtr, _
ByVal dwUrlLength As Long, _
ByVal dwFlags As Long, _
ByRef lpUrlComponents As URL_COMPONENTS) As Long
Sub Test()
Dim result as Long
Dim URLComp As URL_COMPONENTS
Dim mURL as String
mURL = "http://www.stackoverflow.com" & vbNullChar
With URLComp
.dwStructSize = Len(URLComp)
.dwHostNameLength = -1
.dwSchemeLength = -1
.dwUrlPathLength = -1
End With
result = WinHttpCrackUrl(StrPtr(mURL), 0, 0, URLComp)
' Prints 1 on 32-bit Excel/Windows (indicating success)
' Prints 0 on 64-bit Excel/Windows (indicating failure)
Debug.Print result
' Prints 87 on 64-bit Excel/Windows ("The parameter is incorrect.")
Debug.Print err.LastDllError
End Sub
The struct is aligned in the C++ code, but VBA structs are packed. In 32 bit, for your struct, it does not matter since all members have alignment 4. But in 64 bit the pointers need 8 byte alignment and the struct has some extra padding. Put it in like this:
Private Type URL_COMPONENTS
dwStructSize As Long
padding1 As Long
lpszScheme As LongPtr
dwSchemeLength As Long
nScheme As Long
lpszHostName As LongPtr
dwHostNameLength As Long
nPort As Long
lpszUserName As LongPtr
dwUserNameLength As Long
padding2 As Long
lpszPassword As LongPtr
dwPasswordLength As Long
padding3 As Long
lpszUrlPath As LongPtr
dwUrlPathLength As Long
padding4 As Long
lpszExtraInfo As LongPtr
dwExtraInfoLength As Long
padding5 As Long
End Type
I guess you'll want some conditional compilation to switch better 32 and 64 bit versions but I must confess to having no idea how to do that with VBA.
How to convert FILETIME from WinApi (e.g. from result of a call to this WINAPI function to DateTime in vb6? (e.g. if I want to use it as input to the DateTime.DateDiff function.)
Public Type FILETIME
dwLowDateTime As Long
dwHighDateTime As Long
End Type
Public 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 Declare Function FileTimeToSystemTime Lib "kernel32" (lpFileTime As FILETIME, lpSystemTime As SYSTEMTIME) As Long
Private Declare Function SystemTimeToVariantTime Lib "OLEAUT32.DLL" (lpSystemTime As SYSTEMTIME, vtime As Date) As Long
Dim st As SYSTEMTIME
Dim dt As Date
' convert a FILETIME to SYSTEMTIME first
FileTimeToSystemTime ft, st
' convert the SYSTEMTIME to a Variant date (VT_DATE)
SystemTimeToVariantTime st, dt
Currently I am trying to implement a timer class in VBA. For that purpose I use the SetTimer and KillTimer functions of the Windows API...
This is the interface from Msdn:
UINT_PTR WINAPI SetTimer(
__in_opt HWND hWnd,
__in UINT_PTR nIDEvent,
__in UINT uElapse,
__in_opt TIMERPROC lpTimerFunc
);
And this is the way I declared the function wihtin my VBA-Module:
Private Declare Function SetTimer Lib "user32" (ByVal Handle As Long, _
ByVal TimerIDHandle As Any, _
ByVal ElapseTime As Long, _
ByVal AddressOfAndYourHandlerFunctionName As Long) As Long
'TimerIDHandle is of Type Any so I can pass Nothing to the function
I then Call the function this way:
Dim TimerID As Long
TimerID = SetTimer(Application.hWndAccessApp, ByVal 0&, Timer.Timeout, AddressOf TimeOutHandler)
As Vba does not accept a "Null" I have tried implementing "ByVal 0&". Is this the right way to do it?
Anyway...I call this function several times from the same Application and the function always returns 1 as an Identifier even though, according to Msdn, the function should return a unique ID for each timer that is created in the Window handle of the current Access Application.
Furthermore when I created only one timer the Callback function gets Called, but the Timer ID is given as 0, whereas the Settimer-Function returned a 1 at the time of initialization.
Here is my Callback Function Header:
Private Sub TimeOutHandler(ByVal WindowHandle As Long, _
ByVal TimerMessage As Long, _
ByVal TimerID As Long, _
ByVal ElapsedTime As Long)
Where am I wrong?
Any help is greatly appreciated of course ;-)
It worked. If it failed then it would have returned 0. You get a 0 for TimerID in the callback because you passed a 0 for the nIDEvent argument when you created the timer. You'll need to use the value that SetTimer returned to call KillTimer(). Think of it as a timer 'handle'.
You'll never get this code working in 64-bit mode so just declare the 2nd argument as Long.
I have a simple DLL written with VC6 with one function:
__declspec(dllexport) int myfunc(long a, unsigned char *b, unsigned char *c, unsigned char *d, unsigned char *e)
And im calling it from vb6 using:
Declare Function myfunc Lib "mylib.dll" (ByVal a As Long, ByVal b As String, ByVal c As String, ByVal d As String, ByVal e As String) As Long
....
dim a as long
dim b as string
dim c as string
dim d as string
dim e as string
dim r as long
r=myfunc(a,b,c,d,e)
Im getting "bad dll calling convention" error but I cant figure out why. Any ideas?
Generally speaking, 'bad DLL...' means what it says. VB6 requires the _stdcall convention (like the Win API) for any external functions it calls.
Try adding __stdcall to the C function prototype and see what happens.
Check out the Universal DLL function caller, by Paul Caton:
http://www.planet-source-code.com/vb/scripts/ShowCode.asp?txtCodeId=70195&lngWId=1
It will allow you to call pretty much any type of function from VB6.