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RASCS_AuthAck
RASCS_ReAuthenticate
RASCS_Authenticated
RASCS_PrepareForCallback
RASCS_WaitForModemReset
RASCS_WaitForCallback
RASCS_Projected
RASCS_StartAuthentication
RASCS_CallbackComplete
RASCS_LogonNetwork
RASCS_SubEntryConnected
RASCS_SubEntryDisconnected
RASCS_Interactive = RASCS_PAUSED
RASCS_RetryAuthentication
RASCS_CallbackSetByCaller
RASCS_PasswordExpired
RASCS_Connected = RASCS DONE
RASCS_Disconnected
End Enum |
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Do you see it? The code is virtually identical, with only minor changes due to the language syntax. |
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This illustrates an important point: Languages tend to fall into certain classifications. Both Visual Basic and C belong to the class of block-structured languages. They tend to have a great many similarities. One of the most important things that any Visual Basic programmer needs to learn when dealing with the Microsoft documentation is to realize that much of what you already know is directly applicable. A little bit of guesswork and experimentation can solve most API-related problems. |
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Which brings us to the next problemthe callback function. If you got the enumeration correct and were able to run the application, the result was probably an immediate memory exception. Why? |
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Let's look again at the RasDialFunc description: |
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VOID WINAPI RasDialFunc(
UINT unMsg, // type of event that has occurred
RASCONNSTATE rasconnstate, // connection state about to be entered
DWORD dwError // error that may have occurred
); |
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You may not be familiar with callback functions per se, but you should be quite familiar with what an API function would require in this case. Imagine then, for a moment, that this was an exported function. How would you declare it? The API |
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