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refers back to the first insertion string in pMessage (DWORD_PTR)L"Bob", // %4 refers back to the second insertion string in pMessage (DWORD_PTR)6, (DWORD_PTR)L"Bill" }; // %5!*s! int le = Marshal.GetLastWin32Error(); return "Unable to get error code string from System - Error " + le.ToString(); } string sRet = Marshal.PtrToStringAnsi(lpMsgBuf); // Free the buffer. Why do you put keywords in comments rather than simply using keyword syntax which is at least as clear and combines compiler checking with your comments? Top Paul Curtis Thu, 12/13/2012 - 21:10 Windows error reporting can be accomplished a lot more simply; in the following, the error messages are written to text array banner(), which is Source

Now that we've got the project set up, let's back up for a second so I can explain what this project will actually do! Steve - Intel Developer Support Top Repeat Offender Thu, 12/13/2012 - 08:27 !DEC$ IF(.FALSE.) module ifwin use ISO_C_BINDING implicit none private integer, parameter, public :: DWORD = C_LONG integer, parameter, public However, if you use a width and precision specifier, the insert numbers do not correspond directly to the input arguments. Also I meant to set lpBuffer = C_NULL_PTR on line 266, but the value of lpSource is ignored for this value of dwFlags anyway. http://stackoverflow.com/questions/1387064/how-to-get-the-error-message-from-the-error-code-returned-by-getlasterror

Getlasterror Formatmessage

That is not to say it isn't manageable and isn't very useful, but it is nonetheless frustrating at the lack of information when an error occurs. You have characters left. Therefore, the VB designers decided to add the LastDllError to the Err object. The following are possible values of the low-order byte.

Les Top Steve Lionel (Intel) Thu, 12/13/2012 - 07:52 He's got a call to GetLastError in the argument list. strAPIError = Left$(strAPIError, lngRet) ' Return the error string. The function copies the formatted message text to an output buffer, processing any embedded insert sequences if requested. Getlasterror C# How to use GetLastError() Function?

Internally, VB is making Win32 calls all the time in your application. Getlasterror Codes IsPrevAppRunning = True MsgBox GetWin32ErrorDescription(lngVBRet) End If Exit Function error_IsPrevAppRunning: IsPrevAppRunning = False End Function I'll come back to this function in a moment. I hate to think of what calling it would be like under C#. ---------- Will Pittenger E-Mail: mailto:wi************@verizon.net All mail filtered by Qurb (www.qurb.com) Nov 15 '05 #1 Post Reply Share check this link right here now You may run into a situation in your project development where you want to prevent the user from opening up more than one instance of your application.

Let's add this function to our form: Private Function IsPrevAppRunning() As Boolean On Error GoTo error_IsPrevAppRunning Dim lngVBRet As Long mlngHMutex = CreateMutex(0, 0, "MutexTest.frmMutex") lngVBRet = Err.LastDllError If lngVBRet = C# Getlasterror Message This was done for a lot of reasons; such as letting us enter in any value to see what the result would be (not the most exciting thing to do in If you're curious, hop onto Microsoft's web site and look up the documentation on the call. From the MSDN documentation: Formats a message string.

Getlasterror Codes

Syntax C++ Copy DWORD WINAPI FormatMessage( _In_     DWORD   dwFlags, _In_opt_ LPCVOID lpSource, _In_     DWORD   dwMessageId, _In_     DWORD   dwLanguageId, _Out_    LPTSTR  lpBuffer, _In_     DWORD   nSize, _In_opt_ va_list *Arguments ); Parameters dwFlags [in] The formatting options, and how to interpret The value of n can be in the range from 1 through 99. Getlasterror Formatmessage Floating-point format specifiers—e, E, f, and g—are not supported. Getlasterror 2 FORMAT_MESSAGE_FROM_SYSTEM 0x00001000 The function should search the system message-table resource(s) for the requested message.

If this flag is specified with FORMAT_MESSAGE_FROM_HMODULE, the function searches the system message table if the message is not found in the module specified by lpSource. this contact form But I was curious one day, and I started looking into ways to do this myself. If we didn't name the mutex, we'd have to identify it by the return value, which is the handle to the mutex. GetLastError returns a zero, but Err.LastDllError returns the correct error code. Formatmessagew

Since FormatMessage does so many things besides look up error messages, it tends to be a bit of a burden even in C++. What's the deal? For example, %1!*.*s! have a peek here Is the banner variable is defined in a module (as a character(255) :: banner(2) or similar) that contains this function.

Jun 5, 2008 at 2:05pm UTC Duoas (10453) Hmm, I don't know and didn't find anything with a quick google. Str_elems Mattias -- Mattias Sjgren [MVP] mattias @ mvps.org http://www.msjogren.net/dotnet/ Please reply only to the newsgroup. FORMAT_MESSAGE_ALLOCATE_BUFFER tells FormatMessage to allocate memory for the output string.

Here we pass it the C_PTR message_buffer_cptr, !

Steve

RSS Top 21 posts / 0 new Last post For more complete information about compiler optimizations, see our Optimization Notice. Thanks for the heads up, fixed it in my own code base (and my answer). So what's the best situation to be in? Getlasterror 126 Get the string corresponding to this error !

Top Steve Lionel (Intel) Tue, 12/18/2012 - 07:49 If the return value from FormatMessage is 0 you can assume it failed and did not allocate anything. The nSize parameter specifies the minimum number of TCHARs to allocate for an output message buffer. I have since found the best way is to look in the ifwin/ifwinty... http://pubdimensions.com/error-message/window-error-message.php Probably it should be just a char*, cuz my compiler gives me an error cannot convert ‘wchar_t*’ to ‘LPSTR {aka char*}’ for argument ‘5’. –Hi-Angel Aug 13 '14 at 7:59 2

The first one should load up fine, but the second one will show the following two message boxes: That's the last you'll hear from the second instance. However, we'll use one nice little feature of a mutex for our problem at hand: it can be accessed from any process in Windows. The function requires a message definition as input. FORMAT_MESSAGE_FROM_STRING 0x00000400 The lpSource parameter is a pointer to a null-terminated string that contains a message definition.

Shouldn't TS accepted this answer? –swdev Apr 15 '14 at 20:47 If it's necessary for a further throwing there is a simpler way to do it in C# with Most of the time, it takes the form of a return value or some parameter that you pass into the procedure. Now you can change the lpBuffer argument of FormatMessage from string to capture and the nsize argument to 1 because at minimum we need the space for the terminating ASCII NUL. Notes: I like using ATL/MFC CString in Win32 code, I find it very convenient This code is designed for Unicode builds, e.g.

Hard-coded line breaks are coded with the %n escape sequence. Compilable Code: // // Returns a string containing the system error message // corresponding to the given error code. // CString FormatErrorMessage(const DWORD errorCode) { // // Use FormatMessage() Win32 API Similar topics win32 error Where is the part to set when my mouse pointer move to textbox or label or buton it will display text description ? Create a new Standard EXE project in VB called MutexTest.

ServrTrackr - Monitor your SSL certificates, website uptime, and DNS configurations 418,687 Members | 2,303 Online Join Now login Ask Question Home Questions Articles Browse Topics Latest Top Members What commercial flight route has the biggest number of (minimum possible) stops/layovers from A to B? Therefore, if another instance of our application has already created this mutex, CreateMutex will let us know about it. It can come from a message table resource in an already-loaded module.

a non-zero value), so we can't use the return value to let us know if the mutex already exists.