try-catch

问题 In following code I purposefully mistype "@fooData" to "@foo111Data" to check if the try statement is catching my exception. See below code. But the try/catch statement did not catch and display and exception in MessageBox, and VS2010 just break down and highlight the line of wrong code. try { conn.Open(); cmd.Parameters.AddWithValue("@foo111Data", dataStrTb1.Text); cmd.ExecuteNonQuery(); } catch (SqlCeException ex) { MessageBox.Show(ex.ToString()); } finally { conn.Close(); } 回答1: Perhaps an

问题 Before the Swift 2.0 Update this code worked perfectly to download my JSON File from the Server with a PHP Script: let url = NSURL(string: webAdress) let cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalAndRemoteCacheData var request = NSMutableURLRequest(URL: url!, cachePolicy: cachePolicy, timeoutInterval: 5.0) var response: NSURLResponse? = nil var error: NSError? = nil let reply = NSURLConnection.sendSynchronousRequest(request, returningResponse:&response, error:&error) After the

问题 Another follow up to this and this. Actual question Question 1 Upon running into some condition (say a simpleError ), how can I invoke a respective restart handler that systematically tests a range of actual handler functions until one is found that does not result in another condition? If the last available handler has been tried, the default abortion restart handler should be invoked ( invokeRestart("abort") ). The implementation should allow for a flexible specification of the actual

问题 I am a beginner in java, and was playing around with try-catch block.However, I am not able to get the variable outside the try-catch block. The following code works. class factorial{ public static void main(String[] args){ try { int num = Integer.parseInt(args[0]); System.out.println(num ); } catch(Exception e){ System.out.println(e+" Cannot convert arg to int, exiting.."); } } } But the following doesn't works. class factorial{ public static void main(String[] args){ try { int num = Integer

问题 I why can't I return the image I get from the url from within a try block? Sorry for the bad English :(. This is the error I get: Return statement is missing public static Image GetExternalImg(string name, string size) { try { // Get the image from the web. WebRequest req = WebRequest.Create(String.Format("http://www.picturesite.com/picture.png", name, size)); // Read the image that we get in a stream. Stream stream = req.GetResponse().GetResponseStream(); // Save the image from the stream

问题 Im currently programming a visual error GUI that catches any exception while processing and give's the user an "easy to understand" error message. But it seems that I can't catch any exceptions while using the Get-ChildItem cmdlet. Do I have to use a different method than try / catch? Here's the PowerShell script: if ($checkBox1.Checked) { Try{ Get-ChildItem -path K:\adm_spm_logdb_data\ADP\DATA |Rename-Item -newname { $($_.BaseName -split '_provide')[0] + $_.Extension }; }catch [System

问题 catch is not working because there is installed an exception handler using set_exception_handler() I need "catch" to work, so I guess I need to unset the exception handler somehow. Things such as set_exception_handler(NULL) isn't working. Any ideas how to unset the exception handler? function my_exception_handler($exception) { error_log("caught exception: " . $exception->getMessage() ); } set_exception_handler("my_exception_handler"); // QUESTION: how does on unset it ? //set_exception

问题 I was trying to test whether certain file exist using javascript.(don't want to use Ajax). Want to use catch try to handle ERR_FILE_NOT_FOUND error. I tried try{ img.attr('src', url) }catch(err){ console.log("file"+ url + " doesn't exist"); } but it doesn't catch up the error.How do I catch ERR_FILE_NOT_FOUND error? 回答1: Setting the image attribute src isn't going to throw anything based on the results of the file existing or not, it will just simply show the image or not show it. You might

问题 When you catch an exception in an ObjC @catch block, what is the lifecycle of that exception object? I know I can safely use it inside the block, but what if I want to use it again after the block, like this? NSException * exception = nil; @try { // do something risky } @catch(NSException * e) { exception = e; } if (exception) { NSLog(@"Caught exception: %@", exception); } Can I safely stash the reference into another local? Should I be retain, autorelease ing it for safety? Can I retain it

问题 I've been learning to use TPL and have an issue with an example I gathered from this article. I copy and pasted the code exactly as in the Task.Run example but get an error message saying the exception isn't handled: private async void button1_Click(object sender, EventArgs e) { try { await Task.Run(() => { Thread.Sleep(1000); throw new InvalidOperationException("Hi!"); }); } catch (Exception ex) { MessageBox.Show(ex.Message); } } Here's a picture of the error: Is this code example outdated