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Handling Page Crashes with Try-Catch: Enhancing User Experience in Web Development

Page crashes can put a damper on user experience, often leading to frustrating error screens. Even syntactically correct code can fail at runtime. Implementing Try-Catch blocks is essential for error handling and recovery during web development. The TRY block contains potentially risky code, while the CATCH block is designed to manage errors. The FINALLY block ensures certain code executes regardless of success or failure. By utilizing Try-Catch, developers can present user-friendly error messages and recover gracefully from exceptions, enhancing the overall robustness of web applications.

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Handling Page Crashes with Try-Catch: Enhancing User Experience in Web Development

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  1. Handling Ugly Page Crashes With Try - Catch

  2. Handling Ugly Page Crashes • Page crashes are ugly • Syntactically correct code also fails • TRY-CATCH helps recovery • Use TRY-CATCH while developing web pages • TRY contains the risky code • CATCH contains recovery code • FINALLY contains code that must always execute

  3. TRY-CATCH Logic

  4. What it looks like TRY to run this Try Catch (Exception Ex) Finally { there are lines of code here; That have some chance of crashing; } No Error? Run FINALLY anyway Error? Then CATCH it here Continue on Run Finally { List the error message; and any other recovery steps; } { What must always be run; Comes in these lines of code; }

  5. The first checkbox Syntactically perfect pages also fail 1. Customer Registration page 3. First value is #0 4. The last value is #3 So the code loops 4 times The syntax is good. No 4th checkbox  Logic fails. This is a RUNTIME error. 2. There are 3 checkboxes in the list

  6. Page with error WITHOUT Try-Catch

  7. Page with error WITH TRY-CATCH 1. No ugly yellow screen with crazy stuff 2. Error message appears nicely 3. The page actually finishes running Results are in the box!

  8. How to write a TRY-CATCH • Potentially risky code • It in a TRY block • It with a CATCH block just under it • Add a FINALLY block just under that SELECT SURROUND SUPPORT SOMETIMES

  9. For example Try { // sample code here // that has potential to fail } Catch (Exception Ex) { // do this when the code above fails // say what the code in the try block was doing // and what (if you know) the error could be } Finally { // always do this stuff // such as closing readers, // or even connections if you are done with the database }

  10. Circled code has been added ] This code could fail ] If it fails, then run this code to show what the error message is lblErrors.Text=Ex.Message.ToString();

  11. Can you tell what has been added?

  12. Some places to use Try-Catch • Loops, especially where one hard codes counters • While converting between data types • While executing commands, either with DataReaders, or ExecuteNonQueries

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