exception

问题 We are making an Excel-like system. When we open a document and found unsupported functions we threw exception. We just support small subset of excel functions, this could happen frequently. The problem is when there are a lot of cells that contains unsupported functions, lots and lots of exception instances are created. And creating those many exception instances consumes unignorable amount of time. We don't have any special properties within the exception class. What we need to know is the

问题 It was all working an hour ago and many days ago. The link i try to ping is: Link to ping This is the code in form1: nc = new NetworkConnection(); bool bval = nc.PingConnection(satellite_address); if (bval) { label19.Visible = true; label19.Text = "Internet Access"; } else { label19.Visible = true; label19.Text = "No Internet Access"; } When it's trying to execute this line: bool bval = nc.PingConnection(satellite_address); It's going to the nc class: using System; using System.Collections

问题 It was all working an hour ago and many days ago. The link i try to ping is: Link to ping This is the code in form1: nc = new NetworkConnection(); bool bval = nc.PingConnection(satellite_address); if (bval) { label19.Visible = true; label19.Text = "Internet Access"; } else { label19.Visible = true; label19.Text = "No Internet Access"; } When it's trying to execute this line: bool bval = nc.PingConnection(satellite_address); It's going to the nc class: using System; using System.Collections

问题 I'm trying to open a ZIP file in JAVA. The code below works fine except with some large files in which case I get the following exception: Exception in thread "main" java.util.zip.ZipException: invalid CEN header (bad signature) at java.util.zip.ZipFile.open(Native Method) at java.util.zip.ZipFile.<init>(ZipFile.java:114) at java.util.zip.ZipFile.<init>(ZipFile.java:75) Is there a known bug? Can it be due to higher compression level not supported in JAVA? Note that I can not use Winzip to

问题 In another SO question, I've seen several people recommend me to always use TryGetValue. While I always use TryGetValue over the Contains?/Access pattern, I avoid this pattern on purpose when I expect the key to always be in the dictionary. I then go for a direct indexer access, so that an exception is raised if the key isn't there, because something unexpected really happened (i.e. the key wasn't in the dictionary while I expect it to). Since there seems to be a general consensus against my

问题 I'm using panic::catch_unwind to catch a panic: use std::panic; fn main() { let result = panic::catch_unwind(|| { panic!("test panic"); }); match result { Ok(res) => res, Err(_) => println!("caught panic!"), } } (Playground) This seems to work just fine, but I am still getting the output of the panic to stdout. I'd like this to only print out: caught panic! Instead of thread '<main>' panicked at 'test panic', <anon>:6 note: Run with `RUST_BACKTRACE=1` for a backtrace. caught panic! 回答1: You

问题 Exceptions in C++ don't need to be caught (no compile time errors) by the calling function. So it's up to developer's judgment whether to catch them using try/catch (unlike in Java). Is there a way one can ensure that the exceptions thrown are always caught using try/catch by the calling function? 回答1: No. See A Pragmatic Look at Exception Specifications for reasons why not. The only way you can "help" this is to document the exceptions your function can throw, say as a comment in the header

问题 I have the following Class code and when Debug it kept showing the following error: 1.) Unhandled Exception: java.lang.ClassNotfoundException 2.) Unhandled Exception:java.lang.NoSuchMethodException Error Log: /apps/robotapp/Utils.java:32: error: exception IOException is never thrown in body of corresponding try statement } catch (IOException e) { ^ /apps/robotapp/Utils.java:24: error: unreported exception ClassNotFoundException; must be caught or declared to be thrown final int tckName =

问题 I'm trying to add 2 two-digit numbers which are bound to yield a two-digit or three-digit number. Here's what I have so far, and when I try to print the carry, it says Floating Point Exception (Core Dumped) section .data msg db "Enter 2 numbers: " msgLen equ $-msg section .bss numa1 resb 1 numa2 resb 1 numb1 resb 1 numb2 resb 1 carry resb 1 section .text global _start _start: ;print message mov eax, 4 mov ebx, 1 mov ecx, msg mov edx, msgLen int 80h ;accept first number (1st digit) mov eax, 3

问题 I am getting this exception " Object must implement IConvertible. " while converting rules to tolist(). below is my code var rules = from m in db.Rules select m; return rules.ToList().ToDataTable(); // exception occurs here I am using MySQL 6.3.6 ..the same code is working fine with MSSQL. I will be grateful if someone helps me in this regards Umair 回答1: Make sure the source type is convertible to the destination type. Probably the rules.ToList() don't match with you ToDataTable destination