INF: Handling Critical Errors in a Windows Application

ID Number: Q69027

3.00

WINDOWS

Summary:

The Windows SetErrorMode() function controls whether Windows handles

MS-DOS Function 24H errors or allows the calling application to handle

them. Listed below is an example of an MS-DOS Function 24H error and

Windows's method for handling the error: if an application attempts to

access drive A and there is no disk in that drive, Windows displays

the System Error message box "Cannot read from drive A: (Cancel)

(Retry)."

Calling SetErrorMode() allows the application to handle these messages

rather than defaulting to the System Error message box.

The following code fragment demonstrates this process:

SetErrorMode(1); // Allow application to handle system error

...

/* If error occurs, handle it appropriately. */

...

SetErrorMode(0); // Windows will display the standard

// INT 24H error message box for any other

// System Errors.

For more information on a problem in Windows version 3.0 with extended

error handling, query on the following keyword:

WIN9012019