Mega Code Archive

Ioresult - holds the return code of the last i-o operation system unit

function IOResult : Integer; Description The IOResult function retrieves the result of the last I/O (file input/output) operation. This number is zero if the operation succeeded, or a positive number if it failed. Use IOResult when you have disabled the default Delphi IO error trapping. When $IOChecks is On, Delphi raises exceptions for the errors. When Off, Delphi does not raise exceptions, requiring the code to inspect IOResult. Notes Warning : retrieval of the IO result is a one-off activity - the retrieval resets the value to 0. Related commands $IOChecks When on, an IO operation error throws an exception GetLastError Gives the error code of the last failing Windows API call Example code : Create a directory twice, catching the error code var error : Integer; begin // Try to create a new subdirectory in the current directory // Switch off I/O error checking {$IOChecks off} MkDir('TempDirectory'); // Did the directory get created OK? error := IOResult; if error = 0 then ShowMessage('Directory created OK') else ShowMessageFmt('Directory creation failed with error %d',[error]); // Try to create the directory again - this will fail! MkDir('TempDirectory'); error := IOResult; // Save the return code if error = 0 then ShowMessage('Directory created OK again') else ShowMessageFmt('Repeat creation failed with error %d',[error]); // Delete the directory to tidy up RmDir('TempDirectory'); // Switch IO checking back on {$IOChecks on} end; Show full unit code Directory created OK Repeat creation failed with error 183