Error Functions
The Movie Toolbox provides a number of functions that allow your application to examine result codes generated by toolbox functions. In addition, the Movie Toolbox allows your application to provide a function that performs custom error notification. This section discusses these error functions.
The Movie Toolbox maintains two error values for your application: the current error and the sticky error. The current error value contains the result code from the last Movie Toolbox function. The toolbox updates the current error value each time your application calls a Movie Toolbox function. Your application may call the
- IMPORTANT
- The Movie Toolbox introduces an additional error-reporting mechanism. In addition to returning errors as function results, the Movie Toolbox functions return error indications to calling applications by setting one of two values that are private to the Movie Toolbox: a current error value or a sticky error value. Your application can retrieve these values by calling the
GetMoviesErrororGetMoviesStickyErrorfunctions described in this section. To let you know whether there is an error indication, the heading "ERROR CODES" may appear with the entry "None" in function descriptions throughout this chapter.
GetMoviesErrorfunction to obtain the current error value after calling any Movie Toolbox function. Many Movie Toolbox functions do not return an error as a function result--you must use theGetMoviesErrorfunction to obtain the result code. Even if a function explicitly returns an error as a function result, that result is also available using theGetMoviesErrorfunction.The Movie Toolbox saves a result code in the sticky error value. Your application clears the sticky error value by calling the
ClearMoviesStickyErrorfunction. The Movie Toolbox then places the first nonzero result code from any toolbox function used by your application into the sticky error value. The Movie Toolbox does not replace the value in the sticky error value until your application clears the value again. Your application uses theGetMoviesStickyErrorfunction to obtain the result code stored in the sticky error value. In this manner, you can preserve and retrieve important result code information.Your application uses the
SetMoviesErrorProcfunction to designate an error function. The Movie Toolbox calls this error function each time there is an error.
Subtopics
- GetMoviesError
- GetMoviesStickyError
- ClearMoviesStickyError
- SetMoviesErrorProc