Microsoft KB Archive/191501

= How To Detect If the Floppy Drive Is Ready on Windows NT =

Article ID: 191501

Article Last Modified on 7/1/2004

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APPLIES TO


 * Microsoft Visual FoxPro 5.0 Standard Edition
 * Microsoft Visual FoxPro 5.0a
 * Microsoft Visual FoxPro 6.0 Professional Edition

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This article was previously published under Q191501



SUMMARY
The following Microsoft Knowledge Base article describes how to verify that a disk is in a floppy drive:

170609 PRB: PUTFILE Command to Drive "A" Without a Floppy Causes Fault

However, in some instances a formatted unused diskette may be in the drive with a volume serial number of zero. In this case, the code in the article incorrectly indicates that there is not a disk in the drive. The article also mentions the use of the FoxPro DISKSPACE function. However, on a Microsoft Windows NT-based computer or a Microsoft Windows 2000-based computer, the use of the DISKSPACE function opens a system error dialog box if there is not a disk in the drive.



MORE INFORMATION
The following code demonstrates how to indicate the floppy disk status, regardless of the volume serial number. The code does not cause an error dialog box to open on a Windows NT-based computer or a Windows 2000-based computer. The WIN32API function SetErrorMode is used to eliminate the error dialog on both a Windows NT-based computer or a Windows 2000-based computer. *-- Code begins here. *-- Defines from Winbase.h  #define SEM_FAILCRITICALERRORS      0x0001 #define SEM_NOGPFAULTERRORBOX      0x0002 #define SEM_NOALIGNMENTFAULTEXCEPT 0x0004 #define SEM_NOOPENFILEERRORBOX     0x8000

*-- SetErrorMode determines whether the system handles *-- serious errors or whether the program handles them. DECLARE INTEGER SetErrorMode in win32api INTEGER

*-- SetErrorMode returns to what the flags were last set. *-- You need to store this in lnResult so that you can set them *-- back the way they were before calling SetErrorMode. *-- Failure to do so can produce unpredictable results *-- when encountering future errors. SetErrorMode only *-- applies to the current process and therefore only affects *-- the FoxPro program that called SetErrorMode. lnResult = SetErrorMode(SEM_FAILCRITICALERRORS)

*-- Test the FoxPro DISKSPACE function. If you get a -1, then *-- there is no disk in the drive. IF DISKSPACE("a:") = -1 MESSAGEBOX("No disk present.", 0) ELSE MESSAGEBOX("Drive is ready.", 0) ENDIF

*-- Put things back the way you found them. lnResult = SetErrorMode(lnResult)

*-- Test DISKSPACE again. If there is no floppy in the drive, *-- a Windows NT system dialog box appears. IF DISKSPACE("a:") = -1 MESSAGEBOX("No disk present.", 0) ELSE MESSAGEBOX("Drive is ready.", 0) ENDIF *-- Code ends here.

