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Automatically Opening a Device
When you issue a command and specify a device that is not open, MCI tries to
open the device before implementing the command. The following rules apply to
automatically opening devices:
- The automatic open feature works only with the command-string interface.
- The automatic open feature fails for commands that are specific to custom
device drivers.
- Automatically opened devices do not respond to commands that use "all" as a
device name.
- The automatic open feature does not let your application specify the "type"
flag. Without the device name, MCI determines the device name from the entries in
the registry. To use a specific device, you can combine the device name with
the filename by using the exclamation point, as described in the reference
material for the open command.
If an application uses the automatic open feature to open a device, the
application should check the return value of every subsequent open command to verify that the device is still open. MCI also automatically closes
any device that it automatically opens. MCI typically closes a device in the
following situations:
- The command is completed.
- You abort the command.
- You request notification in a subsequent command.
- MCI detects a failure.
Related Links
Software for Delphi and C++ Builder developers
Software for Visual Studio .NET developers
Software for Visual Basic 6 developers
Delphi Tips&Tricks
MegaDetailed.NET
TMS Scripter Studio Pro components for Delphi/C++Builder
More Online Helps
Win32 Programmer's Reference (win32.hlp)
OLE Programmer's Reference (ole.hlp)
Microsoft Windows Pen API Programmer's Reference (penapi.hlp)
Microsoft Windows Sockets 2 Reference (sock2.hlp)
Microsoft Windows Telephony API (TAPI) Programmer's Reference (tapi.hlp)
Unix Manual Pages
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