The following table describes the error codes contained in Winerror.h included with Microsoft Visual C++ version 5.0:

  Automation   Automation
  Error        Error
  in Decimal   in Hex       Error 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 operation
                          not 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 channel
                          control.
-2147467251 (8000400D)    The user supplied memory allocator is
                          unacceptable.
-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 a
                          second time while single threaded.
-2147467245 (80004013)    A Remote activation was necessary but was not
                          allowed.
-2147467244 (80004014)    A Remote activation was necessary but the server
                          name provided was invalid.
-2147467243 (80004015)    The class is configured to run as a security id
                          different from the caller.
-2147467242 (80004016)    Use of Ole1 services requiring DDE windows is
                          disabled.
-2147467241 (80004017)    A RunAs specification must be A RunAs 
                          specification must be 
                          <domain name>\<user name> or simply 
                          <user name>.             
-2147467240 (80004018)    The server process could not be started. The
                          pathname may be incorrect.  
-2147467239 (80004019)    The server process could not be started as the
                          configured identity. The pathname may be
                          incorrect or unavailable.  
-2147467238 (8000401A)    The server process could not be started because
                          the configured identity is incorrect. Check the
                          username and password. 
-2147467237 (8000401B)    The client is not allowed to launch this server. 
-2147467236 (8000401C)    The service providing this server could not be
                          started. 
-2147467235 (8000401D)    This computer was unable to communicate with the
                          computer providing the server. 
-2147467234 (8000401E)    The server did not respond after being launched. 
-2147467233 (8000401F)    The registration information for this server is
                          inconsistent or incomplete. 
-2147467232 (80004020)    The registration information for this interface
                          is 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 associated
                          data 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.dll
                          initialized.
-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 object
                          is 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 structure
                          is invalid.
-2147221395 (8004006D)    Object doesn't support IViewObject interface.
-2147221248 (80040100)    Trying to revoke a drop target that has not been
                          registered.
-2147221247 (80040101)    This window has already been registered as a drop
                          target.
-2147221246 (80040102)    Invalid window handle.
-2147221232 (80040110)    Class does not support aggregation (or class
                          object 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 while
                          converting the bitmap to a DIB.
-2147221052 (800401C4)    Contents of the IStorage not in correct format.
-2147221051 (800401C5)    Contents of IStorage is missing one of the
                          standard streams.
-2147221050 (800401C6)    There was an error in a Windows GDI call while
                          converting 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 a
                          class 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 object
                          server.
-2146959353 (80080007)    Moniker path could not be normalized.
-2146959352 (80080008)    Object server is stopping when OLE service
                          contacts it.
-2146959351 (80080009)    An invalid root block pointer was specified.
-2146959344 (80080010)    An allocation chain contained an invalid link
                          pointer.
-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 to
                          uncompiled 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 OLE
                          hmember. 
-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 another
                          file. 
-2147287035 (80030005)    Access Denied. 
-2147287034 (80030006)    Attempted an operation on an invalid object. 
-2147287032 (80030008)    There is insufficient memory available to
                          complete 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 complete
                          operation. 
-2147286800 (800300F0)    Illegal write of non-simple property to simple
                          property 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 last
                          commit. 
-2147286782 (80030102)    Attempted to use an object that has ceased to
                          exist. 
-2147286781 (80030103)    Can't save. 
-2147286780 (80030104)    The compound file %1 was produced with an
                          incompatible version of storage. 
-2147286779 (80030105)    The compound file %1 was produced with a newer
                          version of storage. 
-2147286778 (80030106)    Share.exe or equivalent is required for
                          operation. 
-2147286777 (80030107)    Illegal operation called on non-file based
                          storage. 
-2147286776 (80030108)    Illegal operation called on object with extant
                          marshallings. 
-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. The
                          file 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 intertask
                          SendMessage call and cannot call out via
                          PostMessage. 
-2147418108 (80010004)    The caller is dispatching an asynchronous call
                          and cannot make an outgoing call on behalf of
                          this call. 
-2147418107 (80010005)    It is illegal to call out while inside message
                          filter. 
-2147418106 (80010006)    The connection terminated or is in a bogus state
                          and cannot be used any more. Other connections
                          are still valid. 
-2147418105 (80010007)    The callee (server [not server application]) is
                          not available and disappeared; all connections
                          are 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 parameter
                          data is incorrect. 
-2147418102 (8001000A)    The call was not transmitted properly; the
                          message queue was full and was not emptied after
                          yielding. 
-2147418101 (8001000B)    The client (caller) cannot marshal the parameter
                          data - low memory, etc. 
-2147418100 (8001000C)    The client (caller) cannot unmarshal the return
                          data - low memory, etc. 
-2147418099 (8001000D)    The server (callee) cannot marshal the return
                          data - low memory, etc. 
-2147418098 (8001000E)    The server (callee) cannot unmarshal the
                          parameter data - low memory, etc. 
-2147418097 (8001000F)    Received data is invalid; could be server or
                          client data. 
-2147418096 (80010010)    A particular parameter is invalid and cannot be
                          (un)marshalled. 
-2147418095 (80010011)    There is no second outgoing call on same channel
                          in DDE conversation. 
-2147418094 (80010012)    The callee (server [not server application]) is
                          not available and disappeared; all connections
                          are 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 thread
                          in single threaded mode. 
-2147417853 (80010103)    The requested interface is not registered on the
                          server object. 
-2147417852 (80010104)    RPC could not call the server or could not return
                          the 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 its
                          clients. 
-2147417847 (80010109)    The object invoked chose not to process the call
                          now. Try again later. 
-2147417846 (8001010A)    The message filter indicated that the application
                          is busy. 
-2147417845 (8001010B)    The message filter rejected the call. 
-2147417844 (8001010C)    A call control interfaces was called with invalid
                          data. 
-2147417843 (8001010D)    An outgoing call cannot be made since the
                          application is dispatching an input-synchronous
                          call. 
-2147417842 (8001010E)    The application called an interface that was
                          marshalled for a different thread. 
-2147417841 (8001010F)    CoInitialize has not been called on the current
                          thread. 
-2147417840 (80010110)    The version of OLE on the client and server
                          machines 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 a
                          reply. 
-2147417834 (80010116)    OLE is waiting before retrying a request. 
-2147417833 (80010117)    Call context cannot be accessed after call
                          completed. 
-2147417832 (80010118)    Impersonate on unsecured calls is not supported. 
-2147417831 (80010119)    Security must be initialized before any
                          interfaces are marshalled or unmarshalled. It
                          cannot be changed once initialized. 
-2147417830 (8001011A)    No security packages are installed on this
                          machine or the user is not logged on or there are
                          no compatible security packages between the
                          client 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) has
                          an 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 this
                          system. 
-2146762750 (800B0002)    The trust verification action specified is not
                          supported by the specified trust provider. 
-2146762749 (800B0003)    The form specified for the subject is not one
                          supported or known by the specified trust
                          provider. 
-2146762748 (800B0004)    The subject is not trusted for the specified
                          action. 
-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 are
                          appropriate, 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 not
                          be determined. 
-2146762741 (800B000B)    This object does not read and write self-sizing
                          data.  
-2146762496 (800B0100)    No signature was present in the subject. 
-2146762495 (800B0101)    A required certificate is not within its validity
                          period. 
-2146762494 (800B0102)    The validity periods of the certification chain
                          do not nest correctly.
-2146762493 (800B0103)    A certificate that can only be used as an
                          end-entity is being used as a CA or visa versa.
-2146762492 (800B0104)    A path length constraint in the certification
                          chain 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 other
                          than that for which it is permitted.
-2146762489 (800B0107)    A parent of a given certificate in fact did not
                          issue that child certificate.
-2146762488 (800B0108)    A certificate is missing or has an empty value
                          for an important field, such as a subject or
                          issuer name.
-2146762487 (800B0109)    A certification chain processed correctly, but
                          terminated in a root certificate which isn't
                          trusted by the trust provider.
-2146762486 (800B010A)    A chain of certs didn't chain as they should in a
                          certain application of chaining. 

因为要在vc中连接数据库，所以在CMyApp::InitInstance()中调用了AfxOleInit()，但是不想，程序在Debug模式刚开始启动的时候报错，调试得出错的断言为

 _AFX_THREAD_STATE* pState = AfxGetThreadState();
 ASSERT(!pState->m_bNeedTerm); // calling it twice?

也就是说，该函数可能被执行了两次，但是搜索整个工程并没有发现啊，于是吧AfxOleInit()前移到InitInstance的最前面，发现没有报错，不断调整，定位到ProcessShellCommand(cmdInfo)这个函数。在此之后pState->m_bNeedTerm被修改。查找这个函数的源代码，

BOOL CWinApp::ProcessShellCommand(CCommandLineInfo& rCmdInfo)
{
 BOOL bResult = TRUE;
 switch (rCmdInfo.m_nShellCommand)
 {
 case CCommandLineInfo::FileNew:
  if (!AfxGetApp()->OnCmdMsg(ID_FILE_NEW, 0, NULL, NULL))
   OnFileNew();
  if (m_pMainWnd == NULL)
   bResult = FALSE;
  break;

  // If we’ve been asked to open a file, call OpenDocumentFile()

 case CCommandLineInfo::FileOpen:
  if (!OpenDocumentFile(rCmdInfo.m_strFileName))
   bResult = FALSE;
  break;

  // If the user wanted to print, hide our main window and
  // fire a message to ourselves to start the printing

………
}

在这里，会执行红色部分，由于我用了CHtmlView文档类，所以在新建时，会调用AfxOleInit()，才导致后面重复调用….呵呵

后来查查微软的文档，其中有：

Why Is MFC Being So ASSERTive?

Dear Dr. GUI,

I saw your article on using COM objects with smart pointers, and I have attempted to use them without success!

I have an MFC SDI application that is based on CHTMLView. I want to use smart pointers to wrap interfaces in the mshtml.tlb type library. Based on your article, I decided to use smart pointers because it looked easy:

#import <mshtml.tlb>
 
CMyAppView::LoadData()
{
   AfxOleInit();  // Initialize the COM library
 
   MSHTML::IHTMLDocument2Ptr pIDoc;
   MSHTML::IHTMLElementCollectionPtr pICollection;
 
   pIDoc = GetHtmlDocument();
   pICollection = pIDoc->Getall();
 
   //use the collection
   int nLength = pICollection->length;
}

But when I run my app, it asserts on the AfxOleInit() call like this:

Debug Assertion Failed!

File: oleinit.cpp

Line: 54

Is there something I have missed in my code?

Regards,

Mark Reed

Dr. GUI replies:

Dr. GUI is flattered that you have taken his advice from previous columns. The good doctor still highly recommends using smart pointers! Unfortunately, the problem you are having with AfxOleInit() is preventing you from even experimenting with their use. So, the doctor has done a triage with his residents and has a diagnosis and a surgical repair that will help with future MFC debug assertions.

The good doctor is convinced that calling AfxOleInit() is necessary when using smart pointers in an MFC application. AfxOleInit() initializes the COM library and should only be called once, preferably at the beginning of your application.

Although it may look like a crash, this debug assertion is much better! Assertions proactively encourage good code health, because they warn you of coding errors that could lead to an actual crash or unexpected behavior. Even better, the condition that causes the assertion can lead directly to the cause of the problem in your code. It follows logically that the first step in your case is to look at the MFC source code (located in ".\VC98\MFC\SRC"). Run your application in the Visual C++ debugger by pressing the F5 key. When you get the debug assertion error, click the Retry button to debug. This opens OleInit.cpp and takes you to the source of the assertion inside the AfxOleInit() function, which looks like this:

ASSERT(!pState->m_bNeedTerm);    // calling it twice?

See the comment? The source code is giving you a hint that this method may be asserting because you are calling AfxOleInit() more than once. But the good doctor went through every line of his code and he is only calling it in our method call. Press the ALT+7 keys to bring up the callstack window. It shows that this assertion does generate from your CMyAppView::LoadData function. How can we know if someone else calls AfxOleInit() before we do?

The trick is to surgically implant a breakpoint in the MFC source code at the very first line of AfxOleInit() (press F9 on that line) and start the application in the debugger again. When the breakpoint is hit, look at the top few lines of the callstack:

AfxOleInit()
COleControlSite::CreateControl(Â…)
Â…
CHtmlView::Create(Â…)

Now, it’s more obvious! Because your view class derives from CHtmlView rather than CView, the CHtmlView::Create() method needs to create a Web Browser control. But, of course, first it calls AfxOleInit() for you.

Phew! That was a lot of work to find out that we don’t need to call AfxOleInit() at all in an MFC application that uses CHtmlView. But hopefully this demonstrates the tremendous benefit in using both the MFC source code and the callstack window. Dr. GUI recommends applying the same techniques to any future debug assertion failures.

This is what the good doctor calls a neat surgery. Your healing time will be negligible.

该段内容大致与我遇到的问题相同。

但是，当我在其中一个对话框类内定义_ConnectionPtr类型成员变量的时候，因为MFC构造各种对话框类型在处理程序命令行参数之前，此时会报错，因为COM未初始化，在我的程序中比较简单，不使用成员变量也可以解决问题，因为局部变量在运行时创建…此时COM已经初始化。对于必须使用成员函数的情况，把AfxOleInit()调用放在ProcessShellCommand()前即可，而并非简单的“That was a lot of work to find out that we don’t need to call AfxOleInit() at all in an MFC application that uses CHtmlView.” 这也算是对microsoft的DR GUI的一点补充吧。一直有个疑问：不知道这个DR是博士，还是“医生”。