Try - Catch
Try - Catch block is very important, and should be used where an error can occur, for example if a file that needs to be read does not exist, you are specifying an invalid path, the current user has not the rights to read and so forth - please read the documentation about System.IO.File.ReadAllText() to see what type of exceptions there are.
In classic VO and Win32 applications, you had to check the return value of an operation, and then eventually ask for more details.
The .NET Framework works differently: it produces an exception, and it is the programmers responsability to treat it correctly.
using System.IO function TestException() as void local cBuffer as string try cBuffer := File.ReadAllText( "c:\temp\This is an invalid filename : txt" ) catch oEx as ArgumentException System.Console.WriteLine( "invalid argument:" + oEx:Message + " in argument " + oEx:ParamName ) catch oEx as NotSupportedException System.Console.WriteLine( "invalid path: " + oEx:Message ) catch oEx as Exception System.Console.WriteLine( "Error reading the file: " + oEx:Message ) end try return
If you don't use the
Try - Catch block, your program is terminated with a unspecified error, and you will not be able to understand what really occurred.
Please see also here: Exceptions