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INFO: Translating Automation Errors for VB/VBA (Long)

Symptoms
This article describes several methods you can use to obtain the messagetext for an error code. This article also contains a list of error codesand descriptions as found in Winerror.h.
NOTE: When errors are raised when working with the Automation in VisualBasic or with VBA (Visual Basic for Applications), the error does notalways include the message text for the error.
Resolution
Refer to Winerror.hWhen automating another application with Visual Basic or VBA, you mayreceive an error similar to the following:

Run-time error ‘-2147418094 (80010012)’:
Automation Error.The value -2147418094 corresponds to the decimal representation of theerror code; 80010012 corresponds to the hexadecimal representation of thesame code. This code is documented in the Microsoft Visual C++ header fileWinerror.h. To locate the error code, search for the hexadecimalrepresentation of the error code (that is, 80010012). The following is anexcerpt from Winerror.h, which describes this error:

//// MessageId: RPC_E_SERVER_DIED_DNE//// MessageText:////The callee (server [not server application]) is not available//and disappeared; all connections are invalid.The call did not//execute.//#define RPC_E_SERVER_DIED_DNE_HRESULT_TYPEDEF_(0×80010012L) Winerror.h is included with Microsoft Visual C++ and is also provided withthe Microsoft Developer Network (MSDN) Library.
NOTE: Automation errors that are specific to a server application are notlisted in Winerror.h. If you do not find the error code in Winerror.h,check the documentation for the server application. Usually, withapplication-specific errors, the last 4 digits of the hexadecimalrepresentation of the error code refer to the application specific error.
Use FormatMessageYou can use the FormatMessage API function to determine the message textassociated with an automation error code. The sample function belowillustrates how you can use FormatMessage to obtain the message text:

Option ExplicitConst FORMAT_MESSAGE_FROM_SYSTEM = &H1000Private Declare Function FormatMessage Lib “kernel32″ Alias _”FormatMessageA” ( ByVal dwFlags As Long, lpSource As Long, _ByVal dwMessageId As Long, ByVal dwLanguageId As Long, _ByVal lpBuffer As String, ByVal nSize As Long, Arguments As Any) _As LongPrivate Function MessageText(lCode As Long) As StringDim sRtrnCode As StringDim lRet As LongsRtrnCode = Space$(256)lRet = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, 0&, lCode, 0&, _sRtrnCode, 256&, 0&)If lRet >0 ThenMessageText = Left(sRtrnCode, lRet)ElseMessageText = “Error not found.”End IfEnd Function The next example illustrates how you can use this function with yourautomation code. In this example, Microsoft Excel is the serverapplication. Referencing a workbook object once it is destroyed (or closed)generates the error. To illustrate how to use the MessageText function,this example purposely generates an automation error by referencing aworkbook object after the workbook has been closed:

Dim xl As ObjectDim book As ObjectDim sMsg As StringSet xl = CreateObject(“excel.application”)Set book = xl.workbooks.Addbook.Close FalseOn Error Resume NextDebug.Print book.Name’<-Generates an automation error because the’workbook referenced by the book object has’been closed.If Err.Number <>0 ThensMsg = MessageText(Err.Number)MsgBox “Automation Error ” & vbCr & Err.Number & _” (” & Hex(Err.Number) & “)” & vbCr & sMsgEnd IfOn Error GoTo 0Set xl = Nothing Referencing the book object after the workbook is destroyed generates therun-time error -2147418094 (80010012). This is the message text returned byFormatMessage for this particular error:

The callee (server [not server application]) is not available anddisappeared; all connections are invalid. The call did not execute.NOTE: The FormatMessage function does not return errors that are specificto an application.
Use “Error Lookup”Microsoft Visual C++ version 5.0 includes a utility called “Error Lookup”that provides the message text for error codes.
To use this utility, start Microsoft Visual C++ and click Error Lookup onthe Tools menu. Type the error code and click Lookup. As an example, if youhad received the previously described error, -2147418094 (80010012), youwould type the following text in “Error Lookup” and then click Lookup:
0×80010012
Error List from WINERROR.HThe following table describes the error codes contained in Winerror.hincluded with Microsoft Visual C++ version 5.0:

AutomationAutomationErrorErrorin Decimalin HexError Description-2147418113 (8000FFFF)Catastrophic failure.-2147942413 (8007000D)The Data is invalid.-2147467263 (80004001)Not implemented.-2147024882 (8007000E)Ran out of memory.-2147024809 (80070057)One or more arguments are invalid.-2147467262 (80004002)No such interface supported.-2147467261 (80004003)Invalid pointer.-2147024890 (80070006)Invalid handle.-2147467260 (80004004)Operation aborted.-2147467259 (80004005)Unspecified error.-2147024891 (80070005)General access denied error.-2147483647 (80000001)Not implemented.-2147483646 (80000002)Ran out of memory.-2147483645 (80000003)One or more arguments are invalid.-2147483644 (80000004)No such interface supported.-2147483643 (80000005)Invalid pointer.-2147483642 (80000006)Invalid handle.-2147483641 (80000007)Operation aborted.-2147483640 (80000008)Unspecified error.-2147483639 (80000009)General access denied error.-2147483638 (8000000A)The data necessary to complete this operationnot yet available.-2147467258 (80004006)Thread local storage failure.-2147467257 (80004007)Get shared memory allocator failure.-2147467256 (80004008)Get memory allocator failure.-2147467255 (84009)Unable to initialize class cache.-2147467254 (8400A)Unable to initialize RPC services.-2147467253 (8000400B)Cannot set thread local storage channel control.-2147467252 (8000400C)Could not allocate thread local storage channelcontrol.-2147467251 (8000400D)The user supplied memory allocator isunacceptable.-2147467250 (8000400E)The OLE service mutex already exists.-2147467249 (8000400F)The OLE service file mapping already exists.-2147467248 (80004010)Unable to map view of file for OLE service.-2147467247 (80004011)Failure attempting to launch OLE service.-2147467246 (80004012)There was an attempt to call CoInitialize asecond time while single threaded.-2147467245 (80004013)A Remote activation was necessary but was notallowed.-2147467244 (80004014)A Remote activation was necessary but the servername provided was invalid.-2147467243 (80004015)The class is configured to run as a security iddifferent from the caller.-2147467242 (80004016)Use of Ole1 services requiring DDE windows isdisabled.-2147467241 (80004017)A RunAs specification must be A RunAsspecification must be<domain name>\<user name> or simply<user name>.-2147467240 (80004018)The server process could not be started. Thepathname may be incorrect.-2147467239 (80004019)The server process could not be started as theconfigured identity. The pathname may beincorrect or unavailable.-2147467238 (8000401A)The server process could not be started becausethe configured identity is incorrect. Check theusername and password. -2147467237 (8000401B)The client is not allowed to launch this server. -2147467236 (8000401C)The service providing this server could not bestarted. -2147467235 (8000401D)This computer was unable to communicate with thecomputer providing the server. -2147467234 (8000401E)The server did not respond after being launched. -2147467233 (8000401F)The registration information for this server isinconsistent or incomplete. -2147467232 (80004020)The registration information for this interfaceis inconsistent or incomplete. -2147467231 (80004021)The operation attempted is not supported. -2147221504 (80040000)Invalid OLEVERB structure.-2147221503 (80040001)Invalid advise flags.-2147221502 (80040002)Can’t enumerate any more, because the associateddata is missing.-2147221501 (80040003)This implementation doesn’t take advises.-2147221500 (80040004)There is no connection for this connection ID.-2147221499 (80040005)Need to run the object to perform this operation.-2147221498 (80040006)There is no cache to operate on.-2147221497 (80040007)Uninitialized object.-2147221496 (80040008)Linked object’s source class has changed.-2147221495 (80040009)Not able to get the moniker of the object.-2147221494 (8004000A)Not able to bind to the source.-2147221493 (8004000B)Object is static; operation not allowed.-2147221492 (8004000C)User cancelled out of save dialog.-2147221491 (8004000D)Invalid rectangle.-2147221490 (8004000E)compobj.dll is too old for the ole2.dllinitialized.-2147221489 (8004000F)Invalid window handle.-2147221488 (80040010)Object is not in any of the inplace active states.-2147221487 (80040011)Not able to convert object.-2147221486 (80040012)Not able to perform the operation because objectis not given storage yet.-2147221404 (80040064)Invalid FORMATETC structure.-2147221403 (80040065)Invalid DVTARGETDEVICE structure.-2147221402 (80040066)Invalid STDGMEDIUM structure.-2147221401 (80040067)Invalid STATDATA structure.-2147221400 (80040068)Invalid lindex.-2147221399 (80040069)Invalid tymed.-2147221398 (8004006A)Invalid clipboard format.-2147221397 (8004006B)Invalid aspect(s).-2147221396 (8004006C)tdSize parameter of the DVTARGETDEVICE structureis invalid.-2147221395 (8004006D)Object doesn’t support IViewObject interface.-2147221248 (80040100)Trying to revoke a drop target that has not beenregistered.-2147221247 (80040101)This window has already been registered as a droptarget.-2147221246 (80040102)Invalid window handle.-2147221232 (80040110)Class does not support aggregation (or classobject is remote).-2147221231 (80040111)ClassFactory cannot supply requested class.-2147221184 (80040140)Error drawing view.-2147221168 (80040150)Could not read key from registry.-2147221167 (80040151)Could not write key to registry.-2147221166 (80040152)Could not find the key in the registry.-2147221165 (80040153)Invalid value for registry.-2147221164 (80040154)Class not registered.-2147221163 (80040155)Interface not registered.-2147221136 (80040170)Cache not updated.-2147221120 (80040180)No verbs for OLE object.-2147221119 (80040181)Invalid verb for OLE object.-2147221088 (800401A0)Undo is not available.-2147221087 (800401A1)Space for tools is not available.-2147221056 (800401C0)OLESTREAM Get method failed.-2147221055 (800401C1)OLESTREAM Put method failed.-2147221054 (800401C2)Contents of the OLESTREAM not in correct format.-2147221053 (800401C3)There was an error in a Windows GDI call whileconverting the bitmap to a DIB.-2147221052 (800401C4)Contents of the IStorage not in correct format.-2147221051 (800401C5)Contents of IStorage is missing one of thestandard streams.-2147221050 (800401C6)There was an error in a Windows GDI call whileconverting the DIB to a bitmap. -2147221040 (800401D0)OpenClipboard Failed.-2147221039 (800401D1)EmptyClipboard Failed.-2147221038 (800401D2)SetClipboard Failed.-2147221037 (800401D3)Data on clipboard is invalid.-2147221036 (800401D4)CloseClipboard Failed.-2147221024 (800401E0)Moniker needs to be connected manually.-2147221023 (800401E1)Operation exceeded deadline.-2147221022 (800401E2)Moniker needs to be generic.-2147221021 (800401E3)Operation unavailable.-2147221020 (800401E4)Invalid syntax.-2147221019 (800401E5)No object for moniker.-2147221018 (800401E6)Bad extension for file.-2147221017 (800401E7)Intermediate operation failed.-2147221016 (800401E8)Moniker is not bindable.-2147221015 (800401E9)Moniker is not bound.-2147221014 (800401EA)Moniker cannot open file.-2147221013 (800401EB)User input required for operation to succeed.-2147221012 (800401EC)Moniker class has no inverse.-2147221011 (800401ED)Moniker does not refer to storage.-2147221010 (800401EE)No common prefix.-2147221009 (800401EF)Moniker could not be enumerated.-2147221008 (800401F0)CoInitialize has not been called. -2147221007 (800401F1)CoInitialize has already been called. -2147221006 (800401F2)Class of object cannot be determined.-2147221005 (800401F3)Invalid class string.-2147221004 (800401F4)Invalid interface string.-2147221003 (800401F5)Application not found.-2147221002 (800401F6)Application cannot be run more than once.-2147221001 (800401F7)Some error in application program.-2147221000 (800401F8)DLL for class not found.-2147220999 (800401F9)Error in the DLL.-2147220998 (800401FA)Wrong OS or OS version for application.-2147220997 (800401FB)Object is not registered.-2147220996 (800401FC)Object is already registered.-2147220995 (800401FD)Object is not connected to server.-2147220994 (800401FE)Application was launched but it didn’t register aclass factory.-2147220993 (800401FF)Object has been released.-2146959359 (80080001)Attempt to create a class object failed.-2146959358 (80080002)OLE service could not bind object.-2146959357 (80080003)RPC communication failed with OLE service.-2146959356 (80080004)Bad path to object.-2146959355 (80080005)Server execution failed.-2146959354 (80080006)OLE service could not communicate with the objectserver.-2146959353 (80080007)Moniker path could not be normalized.-2146959352 (80080008)Object server is stopping when OLE servicecontacts it.-2146959351 (80080009)An invalid root block pointer was specified.-2146959344 (80080010)An allocation chain contained an invalid linkpointer.-2146959343 (80080011)The requested allocation size was too large.-2147352575 (80020001)Unknown interface. -2147352573 (80020003)Member not found. -2147352572 (80020004)Parameter not found. -2147352571 (80020005)Type mismatch. -2147352570 (80020006)Unknown name.-2147352569 (80020007)No named arguments. -2147352568 (80020008)Bad variable type. -2147352567 (80020009)Exception occurred. -2147352566 (8002000A)Out of present range. -2147352565 (8002000B)Invalid index. -2147352564 (8002000C)Unknown language. -2147352563 (8002000D)Memory is locked. -2147352562 (8002000E)Invalid number of parameters. -2147352561 (8002000F)Parameter not optional. -2147352560 (80020010)Invalid callee. -2147352559 (80020011)Does not support a collection. -2147319786 (80028016)Buffer too small. -2147319784 (80028018)Old format or invalid type library. -2147319783 (80028019)Old format or invalid type library. -2147319780 (8002801C)Error accessing the OLE registry. -2147319779 (8002801D)Library not registered. -2147319769 (80028027)Bound to unknown type. -2147319768 (80028028)Qualified name disallowed. -2147319767 (80028029)Invalid forward reference, or reference touncompiled type. -2147319766 (8002802A)Type mismatch. -2147319765 (8002802B)Element not found. -2147319764 (8002802C)Ambiguous name. -2147319763 (8002802D)Name already exists in the library. -2147319762 (8002802E)Unknown LCID. -2147319761 (8002802F)Function not defined in specified DLL. -2147317571 (800288BD)Wrong module kind for the operation. -2147317563 (800288C5)Size may not exceed 64K. -2147317562 (800288C6)Duplicate ID in inheritance hierarchy. -2147317553 (800288CF)Incorrect inheritance depth in standard OLEhmember. -2147316576 (80028CA0)Type mismatch. -2147316575 (80028CA1)Invalid number of arguments. -2147316574 (80028CA2)I/O Error. -2147316573 (80028CA3)Error creating unique tmp file. -2147312566 (80029C4A)Error loading type library/DLL. -2147312509 (80029C83)Inconsistent property functions. -2147312508 (80029C84)Circular dependency between types/modules. -2147287039 (80030001)Unable to perform requested operation. -2147287038 (80030002)%1 could not be found. -2147287037 (80030003)The path %1 could not be found. -2147287036 (80030004)There are insufficient resources to open anotherfile. -2147287035 (80030005)Access Denied. -2147287034 (80030006)Attempted an operation on an invalid object. -2147287032 (80030008)There is insufficient memory available tocomplete operation. -2147287031 (80030009)Invalid pointer error. -2147287022 (80030012)There are no more entries to return. -2147287021 (80030013)Disk is write-protected. -2147287015 (80030019)An error occurred during a seek operation. -2147287011 (8003001D)A disk error occurred during a write operation. -2147287010 (8003001E)A disk error occurred during a read operation. -2147287008 (80030020)A share violation has occurred. -2147287007 (80030021)A lock violation has occurred. -2147286960 (80030050)%1 already exists. -2147286953 (80030057)Invalid parameter error. -2147286928 (80030070)There is insufficient disk space to completeoperation. -2147286800 (800300F0)Illegal write of non-simple property to simpleproperty set. -2147286790 (800300FA)An API call exited abnormally. -2147286789 (800300FB)The file %1 is not a valid compound file. -2147286788 (800300FC)The name %1 is not valid. -2147286787 (800300FD)An unexpected error occurred. -2147286786 (800300FE)That function is not implemented. -2147286785 (800300FF)Invalid flag error. -2147286784 (80030100)Attempted to use an object that is busy. -2147286783 (80030101)The storage has been changed since the lastcommit. -2147286782 (80030102)Attempted to use an object that has ceased toexist. -2147286781 (80030103)Can’t save. -2147286780 (80030104)The compound file %1 was produced with anincompatible version of storage. -2147286779 (80030105)The compound file %1 was produced with a newerversion of storage. -2147286778 (80030106)Share.exe or equivalent is required foroperation. -2147286777 (80030107)Illegal operation called on non-file basedstorage. -2147286776 (80030108)Illegal operation called on object with extantmarshallings. -2147286775 (80030109)The docfile has been corrupted. -2147286768 (80030110)OLE32.DLL has been loaded at the wrong address. -2147286527 (80030201)The file download was aborted abnormally. Thefile is incomplete. -2147286526 (80030202)The file download has been terminated. -2147418111 (80010001)Call was rejected by callee. -2147418110 (80010002)Call was canceled by the message filter. -2147418109 (80010003)The caller is dispatching an intertaskSendMessage call and cannot call out viaPostMessage. -2147418108 (80010004)The caller is dispatching an asynchronous calland cannot make an outgoing call on behalf ofthis call. -2147418107 (80010005)It is illegal to call out while inside messagefilter. -2147418106 (80010006)The connection terminated or is in a bogus stateand cannot be used any more. Other connectionsare still valid. -2147418105 (80010007)The callee (server [not server application]) isnot available and disappeared; all connectionsare invalid. The call may have executed. -2147418104 (80010008)The caller (client) disappeared while the callee(server) was processing a call. -2147418103 (80010009)The data packet with the marshalled parameterdata is incorrect. -2147418102 (8001000A)The call was not transmitted properly; themessage queue was full and was not emptied afteryielding. -2147418101 (8001000B)The client (caller) cannot marshal the parameterdata – low memory, etc. -2147418100 (8001000C)The client (caller) cannot unmarshal the returndata – low memory, etc. -2147418099 (8001000D)The server (callee) cannot marshal the returndata – low memory, etc. -2147418098 (8001000E)The server (callee) cannot unmarshal theparameter data – low memory, etc. -2147418097 (8001000F)Received data is invalid; could be server orclient data. -2147418096 (80010010)A particular parameter is invalid and cannot be(un)marshalled. -2147418095 (80010011)There is no second outgoing call on same channelin DDE conversation. -2147418094 (80010012)The callee (server [not server application]) isnot available and disappeared; all connectionsare invalid. The call did not execute. -2147417856 (80010100)System call failed. -2147417855 (80010101)Could not allocate some required resource(memory, events, …) -2147417854 (80010102)Attempted to make calls on more than one threadin single threaded mode. -2147417853 (80010103)The requested interface is not registered on theserver object. -2147417852 (80010104)RPC could not call the server or could not returnthe results of calling the server. -2147417851 (80010105)The server threw an exception. -2147417850 (80010106)Cannot change thread mode after it is set. -2147417849 (80010107)The method called does not exist on the server. -2147417848 (80010108)The object invoked has disconnected from itsclients. -2147417847 (80010109)The object invoked chose not to process the callnow. Try again later. -2147417846 (8001010A)The message filter indicated that the applicationis busy. -2147417845 (8001010B)The message filter rejected the call. -2147417844 (8001010C)A call control interfaces was called with invaliddata. -2147417843 (8001010D)An outgoing call cannot be made since theapplication is dispatching an input-synchronouscall. -2147417842 (8001010E)The application called an interface that wasmarshalled for a different thread. -2147417841 (8001010F)CoInitialize has not been called on the currentthread. -2147417840 (80010110)The version of OLE on the client and servermachines does not match. -2147417839 (80010111)OLE received a packet with an invalid header. -2147417838 (80010112)OLE received a packet with an invalid extension. -2147417837 (80010113)The requested object or interface does not exist. -2147417836 (80010114)The requested object does not exist. -2147417835 (80010115)OLE has sent a request and is waiting for areply. -2147417834 (80010116)OLE is waiting before retrying a request. -2147417833 (80010117)Call context cannot be accessed after callcompleted. -2147417832 (80010118)Impersonate on unsecured calls is not supported. -2147417831 (80010119)Security must be initialized before anyinterfaces are marshalled or unmarshalled. Itcannot be changed once initialized. -2147417830 (8001011A)No security packages are installed on thismachine or the user is not logged on or there areno compatible security packages between theclient and server. -2147417829 (8001011B)Access is denied. -2147417828 (8001011C)Remote calls are not allowed for this process. -2147417827 (8001011D)The marshalled interface data packet (OBJREF) hasan invalid or unknown format. -2147352577 (8001FFFF)An internal error occurred. -2146893823 (80090001)Bad UID. -2146893822 (80090002)Bad Hash. -2146893821 (80090003)Bad Key. -2146893820 (80090004)Bad Length. -2146893819 (80090005)Bad Data. -2146893818 (80090006)Invalid Signature. -2146893817 (80090007)Bad Version of provider. -2146893816 (80090008)Invalid algorithm specified. -2146893815 (80090009)Invalid flags specified. -2146893814 (8009000A)Invalid type specified. -2146893813 (8009000B)Key not valid for use in specified state. -2146893812 (8009000C)Hash not valid for use in specified state. -2146893811 (8009000D)Key does not exist.-2146893810 (8009000E)Insufficient memory available for the operation. -2146893809 (8009000F)Object already exists. -2146893808 (80090010)Access denied. -2146893807 (80090011)Object was not found. -2146893806 (80090012)Data already encrypted. -2146893805 (80090013)Invalid provider specified. -2146893804 (80090014)Invalid provider type specified. -2146893803 (80090015)Provider’s public key is invalid. -2146893802 (80090016)Keyset does not exist. -2146893801 (80090017)Provider type not defined. -2146893800 (80090018)Provider type as registered is invalid. -2146893799 (80090019)The keyset is not defined. -2146893798 (8009001A)Keyset as registered is invalid. -2146893797 (8009001B)Provider type does not match registered value. -2146893796 (8009001C)The digital signature file is corrupt. -2146893795 (8009001D)Provider DLL failed to initialize correctly. -2146893794 (8009001E)Provider DLL could not be found. -2146893793 (8009001F)The Keyset parameter is invalid. -2146893792 (80090020)An internal error occurred. -2146893791 (80090021)A base error occurred. -2146762751 (800B0001)The specified trust provider is not known on thissystem. -2146762750 (800B0002)The trust verification action specified is notsupported by the specified trust provider. -2146762749 (800B0003)The form specified for the subject is not onesupported or known by the specified trustprovider. -2146762748 (800B0004)The subject is not trusted for the specifiedaction. -2146762747 (800B0005)Error due to problem in ASN.1 encoding process. -2146762746 (800B0006)Error due to problem in ASN.1 decoding process. -2146762745 (800B0007)Reading / writing Extensions where Attributes areappropriate, and visa versa. -2146762744 (800B0008)Unspecified cryptographic failure. -2146762743 (800B0009)The size of the data could not be determined. -2146762742 (800B000A)The size of the indefinite-sized data could notbe determined. -2146762741 (800B000B)This object does not read and write self-sizingdata.-2146762496 (800B0100)No signature was present in the subject. -2146762495 (800B0101)A required certificate is not within its validityperiod. -2146762494 (800B0102)The validity periods of the certification chaindo not nest correctly.-2146762493 (800B0103)A certificate that can only be used as anend-entity is being used as a CA or visa versa.-2146762492 (800B0104)A path length constraint in the certificationchain has been violated.-2146762491 (800B0105)An extension of unknown type that is labeled’critical’ is present in a certificate.-2146762490 (800B0106)A certificate is being used for a purpose otherthan that for which it is permitted.-2146762489 (800B0107)A parent of a given certificate in fact did notissue that child certificate.-2146762488 (800B0108)A certificate is missing or has an empty valuefor an important field, such as a subject orissuer name.-2146762487 (800B0109)A certification chain processed correctly, butterminated in a root certificate which isn’ttrusted by the trust provider.-2146762486 (800B010A)A chain of certs didn’t chain as they should in acertain application of chaining.

How to load an assembly at runtime that is located in a folder that is not the bin folder of the application

Symptoms
You do not have to put an assembly that an application must use at runtime in the bin folder of the application. You can put the assembly in any folder on the system, and then youcan refer to the assembly at runtime.
Resolution
This step-by-step article describes three methods that you can useto refer to the assemblies that are located in folders that are not the bin folder of the application.
RequirementsThis article assumes that you are familiar with the following topics: General familiarity with Microsoft Visual Basic .NET or Microsoft Visual Basic 2005 or with Microsoft Visual C# .NET or Microsoft Visual C# 2005General familiarity with assemblies in Visual Basic .NET or Visual Basic 2005and in Visual C# .NET or Microsoft Visual C# 2005General familiarity with .config files in Visual Basic .NET or Visual Basic 2005 and in Visual C# .NET or Microsoft Visual C# 2005The following list outlines the recommended hardware, software, network infrastructure, and service packs that you need:The Microsoft .NET FrameworkMicrosoft Visual Studio .NET or Microsoft Visual Studio 2005
Method 1: Install the assembly in the global assembly cache (GAC)The GAC is a computer-wide code cache where the common language runtime is installed. The GAC stores assemblies that you specifically designate to be shared by several applications.
Note You can only install strong-named assemblies in the GAC.
To install an assembly in the GAC, follow these steps: StartVisual Studio .NET or Visual Studio 2005. On the File menu, point to New, and then click Project.
The New Project dialog box appears.Under Project Types, click Visual Basic .NET, or click Visual C# .NET.
Note In Visual Studio 2005, click Visual Basic or click Visual C#.Under Templates, click Class Library. In the Name box, type MyAssembly1.In the Location box,type C:\Myassemblies.
By default, the Class1.vb file is created byVisual Basic .NET or Visual Basic 2005. By default, the Class1.cs file is created byVisual C# .NET or Visual C# 2005. Add the following code tothe Class1 class of the Class1.vb file or of the Class1.cs file.
Visual Basic .NET or Visual Basic 2005 code

Public Function HelloWorld() As StringReturn “From Class Library “End FunctionVisual C# .NET or Visual C# 2005 code

public string HelloWorld(){ return “From Class Library”;}On the File menu,click Save All to save the solution.Install the MyAssembly1 assembly in the GAC.
For more information about how to do this in Visual Basic .NET, click the following article number to view the article in the Microsoft Knowledge Base:
315682?(http://support.microsoft.com/kb/315682/) How to install an assembly in the global assembly cache in Visual Basic. NETFor more information bout how to do this in Visual C# .NET, click the following article number to view the article in the Microsoft Knowledge Base:
815808?(http://support.microsoft.com/kb/815808/) How to install an assembly into the global assembly cache in Visual C# .NETCreate a new client application. To do this,follow these steps:In Visual Studio .NET or Visual Studio 2005, create a new Visual Basic .NET or Visual Basic 2005 Windows application or a new Visual C# .NET or Visual C# 2005 Windows application that is named TestClient1.
By default, the Form1.vb file is created by Visual Basic .NET or Visual Basic 2005. By default,the Form1.cs file is created by Visual C# .NET or Visual C# 2005.In Solution Explorer, right-click Add Reference.
The Add Reference dialog box appears.Click Browse, locateC:\MyAssembly, click the MyAssembly1 assembly, and thenclick Open.
Note In this step, C:\MyAssembly is a placeholder for theactual location of the MyAssembly1 assembly.Add the following code to the Form1_Load event of the Form1.vb file or of the Form1.cs file as follows:
Visual Basic .NET or Visual Basic 2005 code

Dim obj1 As New MyAssembly1.Class1()MessageBox.Show(obj1.HelloWorld())Visual C# .NET or Visual C# 2005 code

MyAssembly1.Class1 obj1=new MyAssembly1.Class1();MessageBox.Show(obj1.HelloWorld());On the Debug menu, click Start to build and to run the application.
Method 2: Use an application configuration (.config) file with the <codeBase> tagsA .config file containsthe following settings:Settings that are specific to an applicationSettings that the common language runtime reads, such as the assembly binding policy settings and the remoting objects settingsSettings that the application readsThe <codeBase> tags specify where the common language runtime can find an assembly. The common language runtime applies the settings of the <codeBase> tags from the .config file.The settings of the <codeBase> tags determine the version and the location of the assembly.
To use a .config file with the <codeBase> tags to refer to the assemblies, follow these steps:Create a new Class Library project that isnamed MyAssembly2 by following steps 1 through6 of the “Method 1: Install the assembly in the global assembly cache (GAC)” section.Make the assembly strong-named.
For additional information about how to do this, click either of the article numbers that are mentioned in step 8 of the “Method 1: Install the assembly in the global assembly cache (GAC)” section.Create a new client application. To do this,follow these steps:In Visual Studio .NET or Visual Studio 2005, create a new Visual Basic .NET or Visual Basic 2005Windows application or a new Visual C# .NET or Visual C# 2005 Windows application that is named TestClient2.
By default,the Form1.vb file iscreated by Visual Basic .NET or Visual Basic 2005. By default,the Form1.cs file is created by Visual C# .NET or Visual C# 2005. In Solution Explorer, right-click Add reference.
The Add Reference dialog box appears.Click Browse, click theMyAssembly2 assembly, and then click Open.Under References, right-click MyAssembly2, and then click Properties.
The Properties window appears.In the Properties window, set the Copy Local property of the assembly to False. Add the following code to the Form1_Load event of the Form1.vb file or of the Form1.cs file as follows:
Visual Basic .NET or Visual Basic 2005 code

Dim obj2 As New MyAssembly2.Class1()MessageBox.Show(obj2.HelloWorld())Visual C# .NET or Visual C# 2005 code

MyAssembly2.Class1 obj2=new MyAssembly2.Class1();MessageBox.Show(obj2.HelloWorld());On the Build menu, click Build Solution.Find the publicKeyToken attribute number of the assembly that you created. To do this,follow these steps: At the Visual Studio .NET or Visual Studio 2005 command prompt, locate the following folder:
C:\MyAssemblies\MyAssembly2\bin\debug
Note To find the publicKeyToken attribute number, locatethe folder that containsyour compiled library assembly. Typically, this is the bin folder in your project folder that is mentioned previously in this step.Type the following command:
SN -T MyAssembly2.dll
Note You must use a capital letter “T” to obtain the correct public key.
The command returns a hexadecimal value that represents the publicKeyToken attributenumber of the assembly.To find the version number of the assembly, follow these steps: In Microsoft Windows Explorer, locate the following folder:
C:\Myassemblies\MyAssembly2\bin\debug Right-click the MyAssembly2.dll file, and then click Properties.
The Properties window appears.In the Properties window, click the Version tab.
Note The assembly version is specified in the Value section.Use the publicKeyToken attribute number and the version number to identify the correct assembly.
Note You must provide the publicKeyToken attribute number, the version number, and the path of the MyAssembly2.dll file that uses the <codeBase> tags to refer to theMyAssembly2.dll file at runtime.Adda .config file to the project. To do this,follow these steps:On the Project menu, click Add New Item.In the Add New Item dialog box, click Application configuration file under Templates. Make sure that the file name is App.config, and then click Open.Add the following code to the file:

<configuration><runtime><assemblyBinding xmlns=”urn:schemas-microsoft-com:asm.v1″><dependentAssembly><assemblyIdentity name=”MyAssembly2″culture=”neutral” publicKeyToken=”307041694a995978″/><codeBase version=”1.0.1524.23149″ href=”FILE://C:/Myassemblies/MyAssembly2.dll”/></dependentAssembly></assemblyBinding></runtime></configuration>Note The TestClient2.exe.config file is locatedin the Debug folder or in the Release folder. Both of these folders are locatedin the bin folder. The solution configuration mode that you select determines the location of the TestClient2.exe.config file.Make the following changes in the <assemblyIdentity> tags: Change the name attribute to the name of your library assembly.Change the publicKeyToken attribute to the public key that you determined in step 4 of this section.Make the following changes in the <codeBase> tags: Change the version attribute to the version number of the assembly that you determined in step 5 of this section.Change the href attribute to the path where the DLL is located.On the Debug menu, click Start to build the project,and thenrun the application.
Method 3: Use the AssemblyResolve eventThe AssemblyResolve event fires whenever the common language runtime tries to bind to an assembly and fails. You can use the AddHandler method to add an event handler to the application that returns the correct assembly whenever the AssemblyResolve event fires.
The AssemblyResolve event handler must return an [Assembly] object, and the common language runtime must bind to this object. Typically, you can use the Assembly.LoadFrom method to load the assembly and then to return the object. To do this, follow these steps: Create a new Class Library project that is named MyAssembly3 by following steps 1 through7 of the “Method 1: Install the assembly in the global assembly cache (GAC)” section.Create a new client application. To do this,follow these steps:In Visual Studio .NET or Visual Studio 2005, create a new Visual Basic .NET or Visual Basic 2005 Windows application or create a new Visual C# .NET or Visual C# 2005 Windows application that is named TestClient3.
By default, the Form1.vb file is created by Visual Basic .NET or Visual Basic 2005. By default, the Form1.cs fileis created by Visual C# .NET or Visual C# 2005.Add a Button control to the Form1.vb file or to the Form1.cs file.Double-click the Button1 control, and then add the following code to the Button1_Click event:
Visual Basic .NET or Visual Basic 2005 code

Dim obj3 As New MyAssembly3.Class1()MessageBox.Show(obj3.HelloWorld())Visual C# .NET or Visual C# 2005 code

MyAssembly3.Class1 obj3=new MyAssembly3.Class1();MessageBox.Show(obj3.HelloWorld()); In Solution Explorer, right-click Add reference.
The Add Reference dialog box appears.Click Browse, click the MyAssembly3 assembly, and then click Open.In the References folder, right-click the MyAssembly3 assembly, and then click Properties.
The Properties window appears.In the Properties window, set the Copy Local property of the assembly to False.Add an event handler to the AssemblyResolve event in the Form1_Load event as follows:
Visual Basic .NET or Visual Basic 2005 code

AddHandler AppDomain.CurrentDomain.AssemblyResolve, AddressOf MyResolveEventHandlerVisual C# .NET or Visual C# 2005 code

AppDomain currentDomain = AppDomain.CurrentDomain;currentDomain.AssemblyResolve += new ResolveEventHandler(MyResolveEventHandler);Define the MyResolveEventHandler function as follows:
Visual Basic .NET or Visual Basic 2005 code

Function MyResolveEventHandler(ByVal sender As Object, _ByVal args As ResolveEventArgs) As [Assembly]‘This handler is called only when the common language runtime tries to bind to the assembly and fails.’Retrieve the list of referenced assemblies in an array of AssemblyName.Dim objExecutingAssemblies As [Assembly]objExecutingAssemblies = [Assembly].GetExecutingAssembly()Dim arrReferencedAssmbNames() As AssemblyNamearrReferencedAssmbNames = objExecutingAssemblies.GetReferencedAssemblies()’Loop through the array of referenced assembly names.Dim strAssmbName As AssemblyNameFor Each strAssmbName In arrReferencedAssmbNames’Look for the assembly names that have raised the “AssemblyResolve” event.If (strAssmbName.FullName.Substring(0, strAssmbName.FullName.IndexOf(“,”)) = args.Name.Substring(0, args.Name.IndexOf(“,”))) Then’Build the path of the assembly from where it has to be loaded.Dim strTempAssmbPath As StringstrTempAssmbPath = “C:\assemblies\” & args.Name.Substring(0, args.Name.IndexOf(“,”)) & “.dll” Dim MyAssembly as [Assembly]‘Load the assembly from the specified path.MyAssembly = [Assembly].LoadFrom(strTempAssmbPath)’Return the loaded assembly.Return MyAssemblyEnd IfNextEnd FunctionVisual C# .NET or Visual C# 2005 code

private Assembly MyResolveEventHandler(object sender,ResolveEventArgs args){ //This handler is called only when the common language runtime tries to bind to the assembly and fails. //Retrieve the list of referenced assemblies in an array of AssemblyName. Assembly MyAssembly,objExecutingAssemblies; string strTempAssmbPath=”"; objExecutingAssemblies=Assembly.GetExecutingAssembly(); AssemblyName [] arrReferencedAssmbNames=objExecutingAssemblies.GetReferencedAssemblies(); //Loop through the array of referenced assembly names. foreach(AssemblyName strAssmbName in arrReferencedAssmbNames) { //Check for the assembly names that have raised the “AssemblyResolve” event. if(strAssmbName.FullName.Substring(0, strAssmbName.FullName.IndexOf(“,”))==args.Name.Substring(0, args.Name.IndexOf(“,”))) { //Build the path of the assembly from where it has to be loaded. strTempAssmbPath=”C:\\Myassemblies\\”+args.Name.Substring(0,args.Name.IndexOf(“,”))+”.dll”; break; } } //Load the assembly from the specified path. MyAssembly = Assembly.LoadFrom(strTempAssmbPath); //Return the loaded assembly. return MyAssembly; }On the Debug menu, click Start to run the application.
Note You must import the System.Reflection namespace to run this application.Click Button1 to call the HelloWorld() method of the MyAssembly3 assembly.