Error Handling Methods In Vb.net
resources Windows Server 2012 resources Programs MSDN subscriptions Overview Benefits Administrators Students Microsoft Imagine Microsoft Student Partners ISV Startups TechRewards Events Community Magazine Forums Blogs Channel 9 Documentation APIs and reference Dev centers Retired content Samples We’re sorry. The content you requested has been removed. You’ll be auto redirected in 1 second. Developing with Visual Studio .NET Articles and Columns Visual Basic .NET Articles Visual Basic .NET Articles Introduction to Exception Handling in Visual Basic .NET Introduction to Exception Handling in Visual Basic .NET Introduction to Exception Handling in Visual Basic .NET Accessing the Registry with Visual Basic .NET Adding New Features with User Controls Advanced Features in Visual Basic .NET and Testing for Scalability Around the World with Visual Basic Aspect-Oriented Programming Asynchronous Execution in Visual Basic .NET Asynchronous Method Execution Using Delegates Automatically Generating Proxy Classes Automatically Generating a Web Service Automating COM+ Administration Best Practices for Windows Forms Applications Building an Attribute Documenter and Viewer Building a Progress Bar that Doesn't Progress Calling All Operators Can I Interest You in 5000 Classes? COM+ and MTS, DCOM and MSMQ, Serialization in .NET Compile Options, Loading Images into PictureBoxes, Deploying .NET Apps, and More Create a Graphical Editor Using RichTextBox and GDI+ Creating A Breadcrumb Control Creating a Five-Star Rating Control Creating and Managing Secondary Threads Creating a Product Search Application Using the eBay SDK and Visual Basic .NET Creating Markup Text in Visual Basic .NET Creating Your Own Dynamic Properties and Preserve Property Settings in Visual Basic .NET Data Binding Radio Buttons to a List Data Binding in Visual Basic .NET Deploying Hybrid Visual Basic 6.0 / Visual Basic .NET Applications Deployment Changes in Visual Basic .NET Deploying Assemblies Design an Application Migration Strategy for Visual Basic 6.0 to Visual Basic 2005 Designing With Custom Attributes Diagnose This: Launching and Controlling System Processes with Visual Basic 6
resources Windows Server 2012 resources Programs MSDN subscriptions Overview Benefits Administrators Students Microsoft Imagine Microsoft Student Partners ISV Startups TechRewards Events Community Magazine Forums Blogs Channel 9 Documentation APIs and reference Dev centers Retired content Samples We’re sorry. The content you requested has been removed. You’ll be auto redirected in 1 second. Visual Basic Language Reference Statements Q-Z Statements Q-Z Statements Try...Catch...Finally Statement Try...Catch...Finally Statement Try...Catch...Finally Statement RaiseEvent Statement ReDim Statement REM Statement RemoveHandler Statement Resume Statement https://msdn.microsoft.com/en-us/library/aa289505(v=vs.71).aspx Return Statement Select...Case Statement Set Statement Stop Statement Structure Statement Sub Statement SyncLock Statement Then Statement Throw Statement Try...Catch...Finally Statement Using Statement While...End While Statement With...End With Statement Yield Statement TOC Collapse the table of content Expand the table of content This documentation is archived and is not being maintained. This documentation is archived and https://msdn.microsoft.com/en-us/library/fk6t46tz.aspx is not being maintained. Try...Catch...Finally Statement (Visual Basic) Visual Studio 2015 Other Versions Visual Studio 2013 Visual Studio 2012 Visual Studio 2010 Visual Studio 2008 Visual Studio 2005 Visual Studio .NET 2003 Provides a way to handle some or all possible errors that may occur in a given block of code, while still running code.Syntax Copy Try [ tryStatements ] [ Exit Try ] [ Catch [ exception [ As type ] ] [ When expression ] [ catchStatements ] [ Exit Try ] ] [ Catch ... ] [ Finally [ finallyStatements ] ] End Try PartsTermDefinitiontryStatementsOptional. Statement(s) where an error can occur. Can be a compound statement.CatchOptional. Multiple Catch blocks permitted. If an exception occurs when processing the Try block, each Catch statement is examined in textual order to determine whether it handles the exception, with exception representing the exception that has been thrown. exceptionOptional. Any variable name. The initial value of exception is the value of the throw
for Beginners Try ... Catch in VB .NET This lesson is part of an ongoing tutorial. The previous part is here: Runtime http://www.homeandlearn.co.uk/NET/nets5p4.html Errors VB.NET has a inbuilt class that deals with errors. The Class is called Exception. When an exception error is found, an Exception object is created. The coding structure VB.NET uses to http://www.codeproject.com/Articles/13658/VB-NET-Error-Handling deal with such Exceptions is called the Try Catch structure. In the coding area for your button, type the word Try. Then hit the return key on your keyboard. VB.NET completes error handling the rest of the structure for you: Try Catch ex As Exception End Try The Try word means "Try to execute this code". The Catch word means "Catch any errors here". The ex is a variable, and the type of variable it is is an Exception object. Move your line of code from the previous section to the Try part: Try rt1.LoadFile("C:\test10.txt", RichTextBoxStreamType.PlainText) Catch ex As error handling methods Exception End Try When you run your programme, VB will Try to execute any code in the Try part. If everything goes well, then it skips the Catch part. However, if an error occurs, VB.NET jumps straight to Catch. Add the following to your Catch part: MessageBox.Show(ex.Message) Your coding window should look like this: Because ex is an object variable, it now has its own Properties and methods. One of these is the Message property. Run your programme and test it out. Click your button. You should see the following error message: The message is coming from the "additional Information" section of the error message we saw earlier, the one we didn't handle. But the point about this new message box is that it will not crash your programme. You have handled the Exception, and displayed an appropriate message for the user. If you know the kind of error that a programme might throw, you can get what Type it is from the Error message box you saw earlier. This one: Click the View Details links under Actions to see the following: The first line tells us the Type of Exception it is: System.IO.FileNotFoundEx
Articles Technical Blogs Posting/Update Guidelines Article Help Forum Article Competition Submit an article or tip Post your Blog quick answersQ&A Ask a Question about this article Ask a Question View Unanswered Questions View All Questions... C# questions Linux questions ASP.NET questions SQL questions VB.NET questions discussionsforums All Message Boards... Application Lifecycle> Running a Business Sales / Marketing Collaboration / Beta Testing Work Issues Design and Architecture ASP.NET JavaScript C / C++ / MFC> ATL / WTL / STL Managed C++/CLI C# Free Tools Objective-C and Swift Database Hardware & Devices> System Admin Hosting and Servers Java .NET Framework Android iOS Mobile SharePoint Silverlight / WPF Visual Basic Web Development Site Bugs / Suggestions Spam and Abuse Watch features Competitions News The Insider Newsletter The Daily Build Newsletter Newsletter archive Surveys Product Showcase Research Library CodeProject Stuff communitylounge Who's Who Most Valuable Professionals The Lounge The Insider News The Weird & The Wonderful The Soapbox Press Releases Non-English Language > General Indian Topics General Chinese Topics help What is 'CodeProject'? General FAQ Ask a Question Bugs and Suggestions Article Help Forum Site Map Advertise with us About our Advertising Employment Opportunities About Us Articles » Platforms, Frameworks & Libraries » .NET Framework » General ArticleBrowse CodeStatsRevisionsAlternatives Comments (10) Add your ownalternative version Tagged as .NETWindowsVisual-StudioDev Stats 140.6K views12 bookmarked Posted 2 Apr 2006 VB .NET Error Handling Ujwal Watgule, 2 Apr 2006 CPOL 2.64 (18 votes) 1 2 3 4 5 2.64/5 - 18 votesμ 2.94, σa 3.15 [?] Rate this: Please Sign up or sign in to vote. Introductory tutorial on Visual Basic error handling Introduction In this article, you’ll learn how to build blocks of code that handle run time errors, also referred as exceptions which occur as a result of normal operating conditions for example. Errors due to a disk not being in the drive or to an offline printer. Visual Basic .NET includes the Try---Catch code block, a new syntax for handling error. In this article