Database Search
If you can't find the information using the categories below, post a question over in our WinBatch Tech Support Forum.
TechHome
DllCall Information
- Beep
- Booted UEFI or BIOS
- Calling HLLAPI
- Change Screen Resolution to standard size
- Change Target of My Documents Folder
- Check for Input Idle - No User Input
- Create and Release Mutex
- Crypto API Functions
- Determine XP Home vs XP Pro using GetVersionEx API
- Direct Memory Copy - RtlCopyMappedMemory
- DLL Pointer Problem
- DllCall Additional Information
- DllCall additional info
- DllCall Example from User
- DllCall to CP5DLL32 DLL
- DllCall to GetExitCodeProcess
- DllCall To GetFileAttributesEx
- DllCall With Callback Example
- DllCall with Structures
- DllCalls to Dll with Double as Passed Param
- DllLastError GetLastError Differences
- DllStructAlloc Example
- Dynamically Change Proxy Settings for an Existing IE Session
- Error 1379 - DllCall - Bad Parameter List Error
- Find a DFS Target Given a DFS Link
- Float as a passed param to DLLCALL
- Font Installation
- FreeImage DllCalls
- General DllCall Information
- Get Username via DllCall
- Get Window with Focus
- Get Windows System Error String
- getprocesstimes_udf
- How To Call Windows API Functions
- How to Get Encrypted Attribute from a Directory
- How to Mount a Local Directory as a Drive Letter
- IntControl 32 and Structures
- Keep XP from Going Into Standby
- Link to windows API documentation
- Native WIFI API
- NTFS File Time Stamps
- Open GL Example
- OpenGL Drawing Example
- Pass Strings by Reference with DLLCall using Binary Buffers
- Reading Pixels in an Image
- Refresh Everything By Telling Windows an Association has Changed
- Shell LightWeight API calls to ColorRGBToHLS and ColorHLSToRGB
- SHQueryUserNotificationState
- Stamp text on bitmaps
- Turn Off Monitor
- Using Dll Created in C to Pass Address
- Using lp binary for DLL callback lpstrs
- VB Dll Usage with DllCall
- Why is BinaryEODset Needed
- WinSHow No Activate
- WM_SetIcon Message to Change Icon
Can't find the information you are looking for here? Then leave a message over on our WinBatch Tech Support Forum.
DllLastError GetLastError Differences
Question:
Trying to get lasterror values when using DllCalls I get different results between DllLastError() and a direct call to the GetLastError function using DllCall. Am I missing something obvious, did I do something wrong or is there another explanation?
; Example code
; First try
dllname = StrCat(DirWindows(1),"secur32.dll")
NameFormat = 0 ; Force an error
lpNameBufferSize = 1024
lpNameBuffer = BinaryAlloc(lpNameBufferSize)
nSizeBufferSize = 4
nSizeBuffer = BinaryAlloc(nSizeBufferSize)
errorvalue = 0
BinaryEodSet(lpNameBuffer,lpNameBufferSize)
BinaryEodSet(nSizeBuffer,nSizeBufferSize)
BinaryPoke4(nSizeBuffer,0,lpNameBufferSize)
result = DllCall(dllname,long:"GetUserNameExA",long:NameFormat,lpbinary:lpNameBuffer,lpbinary:nSizeBuffer)
If !result
errorvalue = DllLastError()
Endif
; Read info from buffers here...
; Code removed, I'm interested in the lasterror value
BinaryFree(lpNameBuffer)
BinaryFree(nSizeBuffer)
Message("DllLastError value",errorvalue)
; Second try
; Same code, DllLastError() replaced with a DllCall
dllname = StrCat(DirWindows(1),"secur32.dll")
NameFormat = 0 ; Force an error
lpNameBufferSize = 1024
lpNameBuffer = BinaryAlloc(lpNameBufferSize)
nSizeBufferSize = 4
nSizeBuffer = BinaryAlloc(nSizeBufferSize)
errorvalue = 0
BinaryEodSet(lpNameBuffer,lpNameBufferSize)
BinaryEodSet(nSizeBuffer,nSizeBufferSize)
BinaryPoke4(nSizeBuffer,0,lpNameBufferSize)
result = DllCall(dllname,long:"GetUserNameExA",long:NameFormat,lpbinary:lpNameBuffer,lpbinary:nSizeBuffer)
If !result
; GetLastError function: DWORD GetLastError(void);
dllname = StrCat(DirWindows(1),"kernel32.dll")
errorvalue = DllCall(dllname,long:"GetLastError")
Endif
; Read info from buffers here...
; Code removed, I'm interested in the lasterror value
BinaryFree(lpNameBuffer)
BinaryFree(nSizeBuffer)
Message("GetLastError value",errorvalue)
Exit
Using Winbatch 2004D on Windows 2000 SP4
Answer:
If you were writing your C-language program, you would use GetLastError() directly after making a function call in the Win32 API library that is capable of setting a system error code.When you are using DllCall() or DllCallCDecl() in WinBatch, a lot of other Win32 API functions can be called [that will disturb the system error code] between when DllCall*() is called and when you'd be all to use DllCall() again to call GetLastError(). What WinBatch is doing is that immediately after it calls a function using DllCall*(), it then calls GetLastError() and stores the result so that DllLastError() can return it when called.
User Reply:
OK, I see. So the only way to go here is to use DllLastError() and *not* use the DllCall to get the 'GetLastError' value at all. Thanks for the info.Article ID: W16431
File Created: 2005:02:18:12:20:30
Last Updated: 2005:02:18:12:20:30