Various Project Templates

Visual Studio 2019 has a whole host of project templates to choose from. I would even go as far as to say that it’s now even easier to find the template you need to use due to the filters in the Create a new project window. Let’s have a look at a few of these project templates net.

Console Applications

I remember that the first time that I wrote a single line of code was in a Console Application. This is a great template to use when you don’t need a UI for your application. The Console Application project template running on the .NET Framework can be seen in Figure 2-7.

You will notice that this application is suited for running on Windows machines. But what if you need to run the Console Application across platforms such as Windows, Linux, and macOS? This is where .NET Core comes into play.

The Console Application project template running on .NET Core can be seen in Figure 2-8.

A few years ago (long before .NET Core was ever a thing), I needed to create an application that could be triggered on a schedule. The application’s executable would then be passed one of the several parameters that the application used to determine which database to connect to.

The application had to run without any user intervention to perform some sort of maintenance task. Due to the fact that no user intervention was needed, a Console Application best suited the use case. Be aware that a Console Application can accept user input, but for my purposes with this application, it was not necessary.

Windows Forms Application

In contrast to the Console Application, the Windows Forms application template is used when you need to create an app that has a UI. The project template (like the Console Application) can run on the .NET Framework or on .NET Core as seen in Figure 2-9.

It is important to note that Windows Forms apps built on .NET Core will still only be able to run on Windows and is not able to run on Linux or macOS.

This means that WPF and Windows Forms apps built on .NET Core will only run on Windows. There are no plans to make these application types cross-platform.

Why then use .NET Core for Windows Forms applications? Well, .NET Core applications are very, very fast. So it is well worth thinking about using .NET Core for Windows Forms applications.

It is possible to port Windows Forms applications to .NET Core 3.0. You will need to run a tool called the .NET Portability Analyzer to check if your application uses any APIs not currently supported in .NET Core. If it does, you will need to refactor your code to avoid those unsupported dependencies.

For a detailed step-by-step, refer to the Microsoft Developer channel on YouTube, and look for the video “How to Port Desktop Applications to .NET Core 3.0”. At the time of writing this book, the URL to this video was www.​youtube.​com/​watch?​v=​upVQEUc_​KwU.

Scott Hunter and Olia Gavrysh discuss this topic at the 7:56 minute mark.

Windows Service

If you ever need to create a Windows application that continually runs in the background, performing some specific task, your best choice would be to use a Windows Service template as seen in Figure 2-10.

Imagine that the application needs to monitor specific activity (be that in a database or file system) and then write messages to an event log. A Windows Service is perfectly suited for this purpose.

Windows Services have an OnStart method that allows you to define what needs to happen when the service starts. By definition, Windows Services are long-running applications that need to poll or monitor the system it runs on. To enable the polling functionality, you will need to use a Timer component.

A common mistake is to use a Windows Forms Timer for a Windows Service. You must ensure that you use the timer in the System.Timers.Timer namespace instead.

The System.Timers timer (Figure 2-11) that you add to the Windows Service will raise an Elapsed event at specific intervals.

It is in this Elapsed event that you can write the code that your service needs to run in order to do what it needs to do.

Web Applications

If you need to create applications that are web-based, you will definitely be creating an ASP.NET Web Application. If you have a look at the project templates, you will notice that you can create an ASP.NET Web Application that runs on .NET Core as seen in Figure 2-12.

If you do not need to create an ASP.NET Core Web Application, you can create a web application that runs on the .NET Framework as seen in Figure 2-13.

As can be seen in the template description, these templates will allow you to create a regular Web Forms application, an MVC application or Web API application. If you need to run your application in a browser, then create an ASP.NET Web Forms or ASP.NET MVC application.

A Web API, on the other hand (sometimes also referred to as Web Services), is an application programming interface (API) that allows communication between various clients such as browsers, mobile devices, etc., and other software components such as a database. It can be used as a stand-alone application or as part of an ASP.NET Web Forms or MVC application.

Class Library

The last project template we will be looking at is the Class Library. It is worth noting that the Class Library will create a DLL that you can reuse in your applications. This is the purpose of a Class Library project.

There are many more project templates available in Visual Studio and are dependant on the workloads you have installed.

As you see in Figure 2-14, the Class Library can be based on .NET Core, .NET Framework, or .NET Standard.

You might be wondering what the differences are between the various project templates. You will find a hint when you look at the tags. The Class Library running the .NET Framework will create a DLL that will only work on Windows machines.

The Class Library running .NET Core will create a library that will run on Windows, Linux, and macOS (it’s therefore cross-platform).

The Class Library running on .NET Standard will create a library that is guaranteed to run on all of the platforms supported in Visual Studio. The .NET Standard is a specification of all the APIs that work on all of the platforms. Therefore, if you create a Class Library on .NET Standard, it is guaranteed to run on desktop, mobile, Web, etc.

For more information regarding .NET Standard, have a look at the following article on Microsoft Docs: https://​docs.​microsoft.​com/​en-us/​dotnet/​standard/​net-standard

There are many more project templates to choose from, and the project templates you see will depend on the workloads that you have installed. Explore some of the different workloads available to you, and see what project templates are available to you after installing a particular workload.

Using NuGet in Visual Studio

Developers can access NuGet right from within Visual Studio, but you can also browse www.nuget.org to find packages to use in your applications. In the following example, we will be using NuGet from within Visual Studio to add functionality to our ShipmentLocator application.

I have added a login form to the ShipmentLocator application as seen in Figure 2-15. What I want to do is encrypt the password typed in by the user and compare that to the encrypted password in the database.

As a rule, you should never be able to decrypt a password. If you can decrypt a password, then so can others that have more malicious intentions. After user registration, the encrypted password is stored in a database. Login requests are then encrypted and compared with the encrypted password in the database. If it’s a match, they are successfully authenticated.

This is a very basic login screen but serves the purpose of illustrating how to use NuGet in your projects.

You can definitely roll your own solution when it comes to encryption. Another route to take is to check NuGet to see if there are any solutions available that you can use.

To add a NuGet package to your project, right-click the project in the Solution Explorer, and click Manage NuGet Packages from the context menu as seen in Figure 2-16.

From the NuGet Package Manager screen that is displayed, you can search for a NuGet package based on keywords you enter. As can be seen in Figure 2-17, I will be using a NuGet package called EncryptValidate that I created that provides encryption functionality.

The NuGet Package Manager screen provides a lot of information about the package you are going to install. The current version number is displayed, license information, project URL, as well as the author and download count for the particular package.

The NuGet Package Manager also makes it easy for you to install previous versions of the NuGet package (Figure 2-18) if you find that the latest package does not work properly with your code.

This allows you to easily roll back to a previous version should you need to. After installing the package, the NuGet Package Manager will indicate that this package has been installed as seen in Figure 2-19.

Figure 2-20 shows the NuGet package in the Visual Studio references.

The encrypted password is stored in the database. It is read in and stored in the storedEncrPassw variable. The clear-text password and the stored encrypted password are then validated. If validation succeeds, the user is logged in.

Remember, the code for this project is available on GitHub.

By adding a single NuGet package, we have added functionality to encrypt passwords, validate encrypted passwords, and encrypt and decrypt text using Rijndael, converting text to a SecureString object, reading the value from the SecureString object, and more. All this functionality has been added without having to write the logic ourselves.

This is the power that NuGet provides. It is definitely something you as a developer need to consider using if you do not already do so.

Hosting Your Own NuGet Feeds

For a full list of NuGet hosting products and for more information on creating your own NuGet feeds, have a look at the following link on Microsoft Docs: https://​docs.​microsoft.​com/​en-us/​nuget/​hosting-packages/​overview

Creating Code Snippets

If there is one thing I wish, is that there was a nice interface baked into Visual Studio for creating and adding code snippets. Perhaps one day, but for now we have to do it the old-fashioned way.

Let’s assume that we have created a Custom project template that includes a logging class in our helper classes.

Refer to the previous section regarding Creating Project Templates.

It is also worth noting that the code snippet might be XML, but the file extension must be .snippet for Visual Studio to be able to import it. If you refer back to Figure 2-28, you will notice an Import button on the Code Snippets Manager screen.

Click that button; browse for and import your newly created code snippet for the custom try-catch. You will notice that I have defined the shortcut as tryl for try-catch log.

This time, if you type the tryl shortcut into your code window, you will see that the description and title of the custom try-catch is displayed as seen in Figure 2-30.

When you hit the tab key twice, the custom code snippet is inserted, and the required namespace, ProjectUtilities, which we created earlier as a project template, is imported along with the code snippet. This can be seen in Figure 2-31.

This new code snippet is now available in all your future projects. Your C# code snippets live in the Documents folder in C:Users[USERNAME]DocumentsVisual Studio 2019Code SnippetsVisual C#My Code Snippets.

The code snippet schema reference is available on Microsoft Docs at the following link: https://​docs.​microsoft.​com/​en-us/​visualstudio/​ide/​code-snippets-schema-reference?​view=​vs-2019

More often than not, you will be creating your own code snippets based off of an existing code snippet. This allows you to reuse functionality you know is working in the existing snippet and include it in your own.

Code snippets are definitely a very powerful productivity feature in Visual Studio.

Bookmarks

Let’s say that you are busy finishing up for the day, but just before you check in your code, you notice that there is some code that doesn’t look quite right. It is a method that has a single return statement and you know that you can use an expression body for methods.

You really don’t have the time to play around further because you have already passed the point that you needed to leave for home. So in order to not forget to have a closer look at this tomorrow, you decide to bookmark the method.

Place your cursor at the line of code you want to return to, and hold down Ctrl+K, Ctrl+K and Visual Studio will add a bookmark as seen in Figure 2-32.

The bookmark is added to the side of the code editor and is indicated by a single black bookmark icon.

In order to see all the bookmarks in your project, you can hold down Ctrl+K, Ctrl+W or go to the View menu item and select Other Windows and then click Bookmark window.

The Bookmarks window is displayed as seen in Figure 2-33. From the toolbar in the Bookmarks window, you can group bookmarks in folders, navigate between bookmarks, navigate between bookmarks in the current folder, toggle a bookmark on the currently selected line in code, disable all bookmarks, and delete bookmarks.

There is however another feature not so obvious by looking at this Bookmarks window, and that is the ability to rename bookmarks. To rename a bookmark, click a selected bookmark, and you will see that the name (in this case “Bookmark4”) becomes editable.

Now you can rename your bookmark to something more relevant to what you need to remember as seen in Figure 2-34. Go ahead and add some more bookmarks to other random areas of code. Your Bookmarks window will end up looking rather full.

Now click the delete button on the Bookmarks toolbar. The bookmark is deleted without any confirmation from the user.

This is something I can sort of understand. Imagine how irritating it would be having to confirm every delete, especially when you want to remove only a subsection of bookmarks from your collection.

It is for this reason that I use bookmarks only as a short-term solution to remind me to go and perform some action in code or to refactor something I think needs refactoring.

For me, a bookmark is something I will come back to within the next day or so. Something I don’t want to put off doing. It is, therefore, a temporary placeholder to something I need to revisit.

But what if I wanted to go and add a more permanent pointer to some logic in code? This is where code shortcuts come in. Let’s have a look at this next.

Code Shortcuts

The ability to add code shortcuts in Visual Studio is more helpful when you need to quickly jump to a certain section of code regularly. To add a shortcut to a specific section of code in Visual Studio, you need to place your cursor on the line of code you need to revisit and type Ctrl+K, Ctrl+H.

Visual Studio will then add the shortcut as seen in Figure 2-36. To view all the shortcuts added to your project, hold down Ctrl+, Ctrl+T or go to the View menu, and select Task List to open the Task List window as seen in Figure 2-37.

Now have a look at your Task List. You will notice that the TODO comment has been added to your Task List as seen in Figure 2-38.

This is a nice and quick method for adding reminders to your code so that you can easily refer to them and navigate to them by double-clicking the item in the Task List. You can, therefore, use the Task List to take you directly to the predefined location in code.

These are by no means case sensitive and will appear in your Task List if following the form in Listing 2-5. You can also add your own custom tokens. Let’s see how to do that next.

Adding Custom Tokens

I like the idea of TODO to add items to my Task List, but I would also like to add a custom token to add an entry in my Task List that is a nice to have feature. Something that is less restrictive than a TODO, because that implies that this action must be completed.

I do not want to have a bunch of TODO entries for items that are simply nice to have features. For this reason, I want to add a custom token called NOTE that is simply a reminder to look at something, if and when I have the time.

To add the custom token, go to the Tools menu, and click Options. Under Environment, select Task List as seen in Figure 2-39.

In the Name text box, add the word NOTE and set the priority to Low. Then click the Add button. The custom token NOTE is added as can be seen in Figure 2-40.

Adding a NOTE to your code will pop up in your Task List as a low priority task as seen in Figure 2-41.

Being able to add custom tokens in Visual Studio, as well as applying a priority to each, allows you to be very specific with comments that contain tokens. This way you can greatly increase the ease and efficiency of navigating through a large code base.

Running SQL Queries

The Server Explorer also allows developers to run SQL queries, right from within Visual Studio. Go ahead and right-click a table (Figure 2-50), and click New Query from the context menu.

Take note that the context menu changes depending on what item you have right-clicked in the Server Explorer. When right-clicking a table, you will see items related to a SQL table. When right-clicking a View, you will see items specific to the View such as Show Results and Open View Definition. When right-clicking a Stored Procedure, the context menu will display the Execute command.

When you have pasted the SQL statement (Figure 2-51), execute it by clicking the run button, by holding down Ctrl+Shift+E or executing it with the debugger by holding down Alt+F5.

If you are used to pressing F5 in SQL Server Management Studio, you might find yourself starting the Visual Studio debugger instead of running the query. I simply find it easier to click the run button and avoid my muscle memory faux pas.

If we run the SELECT statement again, you will see that the entry has been added to the table as seen in Figure 2-52.

When we look at the table data after the UPDATE statement (Figure 2-53), you will see that the table has been updated to display the correct priceCategory values for the items contained in the table.

While running SQL statements isn’t mind-blowing, it is very convenient being able to do all this without ever leaving Visual Studio. The Server Explorer definitely offers much more functionality than illustrated in this chapter. Dig around it a bit more, and see what the Server Explorer can do for your productivity.

C# Interactive

How often have you wanted to test a small bit of code just to see if it works correctly? Well, with C# Interactive, you can do just that without having to debug your entire solution. Found toward the bottom of the View, Other Windows menu, C# Interactive is almost hidden. But gems usually are and you’re going to love using it if you don’t already.

The results are immediately displayed below the code you pasted. Your C# Interactive window should now look as in Figure 2-55.

C# Interactive is what we refer to as a REPL (Read-Eval-Print Loop). Being able to input expressions that are evaluated and results returned makes on the spot debugging possible in Visual Studio.

C# Interactive supports IntelliSense, so you get the same kind of editor experience as in Visual Studio. For a list of available keyboard shortcuts, REPL commands, and Script directives that C# Interactive supports, just type in #help and press the Enter key.

Code Metrics Results

The project that we have been using in this chapter is really not complex at all. It is really just to illustrate the concepts in this book. If you take a more complex project, one of the projects you have worked on at work, this next screen will look a lot different.

Code Metric Results (Figure 2-56) is a set of measurements that allow developers to gain a better insight into the code that they are producing.

The image in Figure 2-56 are the results for the ShipmentLocator application we have been using throughout this chapter. It’s not really complex at all, so the metrics might seem all fine.

Please note that when you first open the Code Metrics Results screen, it will be blank. You need to click the Calculate Code Metrics for Solution button in the top left corner of the window.

Looking at the same screen (Figure 2-57) for a more complex project (one of my old legacy projects), the metrics are quite different.

The advantage of these metrics makes it possible for developers to understand what portions of code need to be worked on or more rigorously tested. It also allows developers to identify potential risks in their software. Ratings in this window are also color coded so that developers can quickly identify trouble spots.

Send Feedback

The Visual Studio team definitely takes feedback seriously. So much so that it drives much of what they do to improve Visual Studio.

If you are experiencing a problem in Visual Studio 2019, click the feedback button as seen in Figure 2-58.

You can now report a problem or suggest a feature right from inside Visual Studio 2019.

As a developer, we should take the time to report issues we come across. This can be anything from crashes to slow performance or something else unexpected.