Validating a Bug Fix with the Debugger

Were you able to resolve the issue? 0:00 Let's walk through the solution now. 0:02 So it turns out we're making a simple mistake. 0:04 We aren't setting the Id property on our model instances. 0:08 To fix the problem let's set the Id property values to 1,2, and 0:12 3 respectively for our model instances. 0:17 Restart the website and browse to /ComicBooks/ Detail/1. 0:23 Okay, we're at our break point again just inside the detail action method. 0:30 Just like last time, we could use F10 and 0:35 F11 to step through our code until we get to the get comic book methods for 0:38 each loop or we could set another breakpoint on that line of code. 0:43 To save us a little time, let's set another breakpoint. 0:48 Switch to the comic book repository class and set a breakpoint on the line of code 0:51 that contains the if statement inside of the for each loop. 0:56 Now we can press F5 to continue execution up to that breakpoint. 0:59 This time in the Autos window, we can see that the comicBook Id property value is 1. 1:05 Press F10 twice to step down to the comic book to return variable assignment. 1:10 Press F10 again to move to the break statement, 1:17 which will break us out of the loop when we press F10 one more time. 1:20 Isn't it cool to see the benefits of short circuiting the loop 1:24 as we step through the code? 1:28 Press Shift+F11 to step out of the method and return to the detail method, 1:30 then press F10 to step down to the return statement. 1:35 Now we can see that the comicBook variable is set to our first comic book, 1:39 The Amazing Spider-Man #700. 1:43 Press F5 to resume execution, and here's our comic book detail page. 1:46 While we're here, let's go ahead and browse to the other two comic books. 1:52 Just change the 1 in the URL to 2 and press Enter. 1:56 We're at our breakpoint again. 2:01 Press F5 to continue execution to our second break point. 2:03 We can see that the id argument value is 2 and the comicBook.Id property value is 1. 2:07 That should cause our if statement to evaluate to false. 2:14 Press F10 to step to the next statement. 2:17 Sure enough the if statement evaluated to false as we expected. 2:20 Press F5 to continue to our breakpoint again. 2:25 Now our comicBook.Id property value is 2, which matches our ID argument value. 2:27 Press F10 twice to see execution fall into the if statement. 2:34 We found the comic book that we're looking for. 2:39 Press F5 to continue execution. 2:41 And here's the comic book detail page showing the information for 2:45 the Amazing Spider Man number 657. 2:49 Now change the 2 in the URL to 3 and press Enter. 2:52 We're at our first breakpoint again. 2:57 This time let's disable all of our breakpoints before we continue execution. 2:59 Click on the Breakpoints tab here at the bottom to show the Breakpoints window. 3:04 Then click on the check boxes here and here to disable our breakpoints. 3:08 Notice how the little red circles are no longer filled in. 3:14 That's how Visual Studio officially indicates that a breakpoint is disabled. 3:18 Press F5 to continue execution. 3:22 And here's our third comic book. 3:26 Let's close Chrome and stop our website. 3:28 If you're using GitHub, let's commit our changes. 3:32 Enter a commit message of Updated comic books controller to use repository. 3:35 And click the Commit All button. 3:44 Let's also sync with the remote server. 3:46 Navigate to the synchronization panel and click the push link. 3:49 >> The Visual Studio debugger offers a great set of tools for 3:55 debugging errors and helping you get more familiar with your code. 3:58 Experienced developers often don't consider a coding task completed until 4:03 they've stepped through their code line by line, validating its runtime behavior. 4:08 As we were debugging you probably noticed that we did a lot of switching back and 4:14 forth between Visual Studio and our browser. 4:19 It's not uncommon for 4:22 developers to have at least two monitors, which allows Visual Studio and 4:23 the browser to be displayed at the same time, one on each monitor. 4:28 We're just scratching the surface of what can be done with the debugger. 4:33 See the teachers notes for links to additional resources. 4:36 Let's do a quick review of the section. 4:40 We improved the structure of our [SOUND] comic book data by adding our first data 4:42 models. 4:47 We learned how [SOUND] strongly typed views can be used to eliminate any 4:47 reliance on the view bag property. 4:52 [SOUND] We applied software design principles and the [SOUND] repository 4:54 design pattern to improve the overall code quality of our website. 4:59 And we saw how to use the Visual Studio debugger to troubleshoot an error. 5:03 We've been busy, great job sticking with it. 5:10 In the next section, we'll work on adding a comic book's list page to our website. 5:13 I'm looking forward to finally having a homepage. 5:18 See you then. 5:22