try-catch

问题 I am trying to get the ideal way to handle exception. I googled & read that I should put try catch in the catch block as well to handle but what if any exception occurs in the nested block itself. try { int a = 10; int b = 0; int c = a / b; Console.WriteLine(c); Console.ReadKey(); } catch (Exception ex) { int a = 10; int b = 0; int c = a / b; Console.WriteLine(ex.Message.ToString()); Console.ReadKey(); } finally { Console.WriteLine("Some Exception"); } On googling I read that it should be

问题 I'm trying to print nested exceptions using the following example code from cppreference.com: void print_exception(const std::exception& e, int level = 0) { std::cerr << std::string(level, ' ') << "exception: " << e.what() << '\n'; try { std::rethrow_if_nested(e); } catch(const std::exception& e) { print_exception(e, level+1); } catch(...) {} } However, I get an abort if the innermost exception is a std::nested_exception rather than a std::exception (IE I throw a std::nested_exception , catch

问题 i have given a chance to my software user to select dll from openfile dialog.(so my user can download dlls form my website and use it with the main project ). everything is working fine and it can even find that dlls is provided by me or selected an invalid dll.but the problem raises if the user selects a renamed file(eg : apple.txt file renamed to apple.dll ). i typed the code like this try dllHandle := LoadLibrary( pwidechar(openfiledialog1.filename)) ; catch { showmessage if it is not a

问题 I'm trying to implement a bug reporting system in my code so I put a try/catch around the function that is run to start the program. It's a programmatic GUI so most of the subfunctions are callbacks for buttons or other GUI elements. However whenever an error is thrown in these subfunctions, it is not caught. Some of the subfunctions are defined in other files as they are other programmatic GUI files. My question is, is there anyway to catch errors that are more than one function level deep?

问题 What is the proper way to wrap semaphore actions in a try-catch block? What happens if the acquire action is interrupted after it has acquired some number, but not all, of the permits requested? How do you know how many to release again? Should the release go in a "finally" block, but then aren't you possibly releasing permits you didn't get if the action was interrupted? try { lock.acquire(permits); //Do some things that require synchronization //Make sure to release all of the permits again

问题 I am trying to catch sql error raised when I execute a stored procedure on a linked server. Both Servers are running SQL Server 2005. To prove the issue I have created a stored procedure on the linked server called Raise error that executes the following code: RAISERROR('An error', 16, 1); If I execute the stored procedure directly on the linked server using the following code I get a result set with 'An error', '16' as expected (ie the code enters the catch block): BEGIN TRY EXEC [dbo].

问题 I'm using Dev-Pas 1.9.2 and am trying to make sure the program doesn't crash when a symbol or a letter value is entered. I've googled and googled and can't find any resoruce on how to achieve this. Any help is greatly appreciated. Thanks! Here is the code I'm trying to manage the input: Function GetMenuChoice : Integer; Var OptionChosen : Integer; Begin Write('Please enter your choice: '); Readln(OptionChosen); If (OptionChosen < 1) Or ((OptionChosen > 4) And (OptionChosen <> 9)) Then Begin

问题 I use sp_start_job to start a job. The job ( test2 ) has only one step: select getdate() waitfor delay '00:00:10' The TRY/CATCH code: begin try EXEC msdb.dbo.sp_start_job @job_name = 'test2' end try begin catch print 'error' end catch First run of the code: Job 'test2' started successfully. Second run of the code (within 10 seconds): Msg 22022, Level 16, State 1, Line 0 SQLServerAgent Error: Request to run job test2 (from User sa) refused because the job is already running from a request by

问题 Once an exception is caught in this code, the menuSystem method is run, but once I go to input a number the programme closes and the "Build is successful" message is displayed. Is there any way to get back into the while loop once an exception has occured? public static void main(String[] args) { final UnitResults myUnit = new UnitResults(10, "Java"); int option = menuSystem(); try { while (option != 0) { final Scanner keyb = new Scanner(System.in); System.out.println(""); switch (option) { }

问题 research this code: public class TestFinalAndCatch { private final int i; TestFinalAndCatch(String[] args) { try { i = method1(); } catch (IOException ex) { i = 0; // error: variable i might already have been assigned } } static int method1() throws IOException { return 1; } } compiler says that java: variable i might already have been assigned But for me it is looks like impossible situation. 回答1: i is final, so it can only be assigned once. The compiler is probably not smart enough to