The Code Editor Window Layout

When you open a code file for editing, you are working in the code editor window, as shown in Figure 4-1. The core of the code editor window is the code pane in which the code displays.

Above the code pane are three drop-down lists that can help you navigate the code file. Known as the Navigation Bar, it can be turned on or off through the Text Editor ➪ All Language ➪ General node of the Options dialog (Tools ➪ Options). Or you can turn it on and off for individual languages.

The first drop-down lists the projects in which the file can be found. This capability is present to support the shared file functionality that Visual Studio offers. The second drop-down contains the different classes defined in the code file, and the third one lists the members of the class selected in the second drop-down. These are listed in alphabetical order, making it easier to find a method or member definition within the file.

As you modify the code in the code editor window, lines of code that you’ve modified since the file has been opened are marked in the left margin — yellow for unsaved changes and green for those that have been saved.

Regions

Effective class design usually results in classes that serve a single purpose and are not overly complex or lengthy. However, there will be times when you have to implement so many interfaces that your code file will become unwieldy. In this case, you have a number of options, such as partitioning the code into multiple files or using regions to condense the code, thereby making it easier to navigate.

The introduction of partial classes (where the definition of a class can be split over two or more files) means that at design time you can place code into different physical files representing a single logical class. The advantage of using separate files is that you can effectively group all methods that are related; for example, methods that implement an interface. The problem with this strategy is that navigating the code then requires continual switching between code files.

An alternative is to use named code regions to condense sections of code that are not currently in use. In Figure 4-2 you can see that two regions are defined, called Constructor and Event Handlers. Clicking the minus sign next to #region condenses the region into a single line and clicking the plus sign expands it again.

Outlining

In addition to regions that you have defined, you have the ability to auto-outline your code, making it easy to collapse methods, comments, and class definitions. Auto-outlining is enabled by default, but if it’s not enabled you can enable it using the Edit ➪ Outlining ➪ Start Automatic Outlining menu item. Before you get freaked out, you won’t see this menu item if automatic outlining is enabled. Instead, you’ll see a Stop Outlining menu item.

Figure 4-3 shows four condensable regions. One is a defined region called Constructor; however, there are also three other automatic regions, outlining the class, the XML comments, and the constructor method (which has been collapsed). Automatic outlines can be condensed and expanded in the same way as regions you define manually.

The Edit ➪ Outlining menu provides a number of commands to help in toggling outlining, such as collapsing the entire file to just method/property definitions (Edit ➪ Outlining ➪ Collapse to Definitions) and expanding it to display all collapsed code again (Edit ➪ Outlining ➪ Toggle All Outlining). The other way to expand and condense regions is via the keyboard shortcut Ctrl+M, Ctrl+M. This shortcut toggles between the two layouts.

Code Formatting

By default, Visual Studio 2017 assists you in writing readable code by automatically indenting and aligning. However, it is also configurable so that you can control how your code is arranged. Common to all languages is the ability to control what happens when you create a new line. In Figure 4-4 you can see that there is a Tabs node under the Text Editor ➪ All Languages node of the Options dialog. Setting values here defines the default value for all languages, which you can then overwrite for an individual language using the Basic ➪ Tabs node (for VB.NET), C# ➪ Tabs, or other language nodes.

By default, the indenting behavior for both C# and VB.NET is smart indenting, which will, among other things, automatically add indentation as you open and close enclosures. Smart indenting is not available for all languages, in which case block indenting is used.

Visual Studio’s Smart Indenting does a good job of automatically indenting code as it is written or pasted into the code editor, but occasionally you can come across code that has not been properly formatted, making it difficult to read. To have Visual Studio reformat the entire document and set the brace locations and line indentations, select Edit ➪ Advanced ➪ Format Document or press Ctrl+K, Ctrl+D. To reformat just the selected code block, select Edit ➪ Advanced ➪ Format Selection or press Ctrl+K, Ctrl+F.

When writing code, to indent an entire block of code one level without changing each line individually, simply select the block and press Tab. Each line has a tab inserted at its start. To unindent a block one level, select it and press Shift+Tab.

Navigating Forward/Backward

As you move within and between items, Visual Studio 2017 tracks where you have been, in much the same way that a web browser tracks the sites you have visited. Using the Navigate Forward and Navigate Backward items from the View menu, you can easily go back and forth between the various locations in the project that you have changed. The keyboard shortcut to navigate backward is Ctrl+−. To navigate forward again it is Ctrl+Shift+−.

Additional Code Editor Features

The Visual Studio code editor is rich with far more features than we can cover in depth here. However, here are a few additional features that you may find useful.

Reference Highlighting

Another great feature is reference highlighting, also known as Code Lens. All uses of the symbol (such as a method or property) under the cursor within its scope are highlighted (as shown in Figure 4-5). This makes it easy to spot where else this symbol is used within your code. You can easily navigate between the uses by Ctrl+Shift+Up/Down.

Line Numbers

To keep track of where you are in a code file, you may find it useful to turn on line numbers in the code editor (as shown in Figure 4-6). To turn line numbers on, go to Tools ➪ Options, expand the Text Editor node, select the All Languages subnode, and select the Line Numbers option.

Visual Studio 2017 includes a code editor feature named the Heads Up Display. In Figure 4-6, notice the small bit of text above the class declaration and the method signature (2 references and 0 references, respectively, along with information about how many uncommitted changes have been made, if this code has been checked into source control). This text indicates the number of times that the class or method is referenced elsewhere in the project.

If you click the text, a pop-up window displays (an example is shown in Figure 4-7) that includes some useful details about the references. This includes the file names and line numbers where the references are found.

If you double-click one of the references, that file opens up in the editor window and the cursor is placed on the line that references the method or class. Just hovering your mouse over a reference causes a pop-up window to display; the window contains not just the line you’re hovering over, but also the two or three lines before and after it, which enables you to see a little more detail about the reference without navigating directly to the file.

Split View

Sometimes you want to view two different parts of the same code file at the same time. Split view enables you to do this by splitting the active code editor window into two horizontal panes separated by a splitter bar. These can then be scrolled separately to display different parts of the same file simultaneously (as shown in Figure 4-8).

To split a code editor window, select Split from the Window menu. Alternatively, drag the handle directly above the vertical scrollbar down to position the splitter bar.

Drag the splitter bar up and down to adjust the size of each pane. To remove the splitter simply double-click the splitter bar, or select Remove Split from the Window menu.

Tear Away (Floating) Code Windows

If you have multiple monitors, a great feature is the ability to “tear off” or float code editor windows (and tool windows) and move them outside the main Visual Studio IDE window (as shown in Figure 4-9), including onto another monitor. This allows you to make use of the extra screen real estate that having multiple monitors provides by enabling multiple code editor windows to be visible at the same time over separate monitors. It is also possible to place these floating windows onto a “raft” so that they can be moved together (as shown in Figure 4-10). To tear off a window, make sure it has the focus, and then select Float from the Window menu. Alternatively, right-click the title bar of the window and select Float from the drop-down menu, or simply click and drag the tab for that window (effectively tearing it away from its docked position) and position it where you want it to be located.

You may find halving the code editor window in Split view (discussed in the previous section) to view different parts of a file at the same time too much of a limited view, so you might want to use the floating code windows feature instead to open another code editor window for the same file, and place it, say, on a different screen (if you have a multiple monitor setup). The trick to doing this (because double-clicking the file again in the Solution Explorer simply activates the existing code editor window instance for that file) is to select New Window from the Window menu. This opens the file currently being viewed in another window, which you can then tear away and position as you please.

Duplicating Solution Explorer

If you work in a multi-monitor environment, a limitation in early versions of Visual Studio was that only one copy of Solution Explorer was available. In Visual Studio 2017, this limitation does not exist. Right-click one of the elements in the Solution Explorer and select New Solution Explorer View. When clicked, a new floating Solution Explorer window is created. This window can be moved around, just like the windows previously described. Figure 4-11 illustrates the newly created Solution Explorer.

Creating Tab Groups

If you don’t have the privilege of having more than one monitor, it is still possible to view more than one code editor window at the same time. You do this by creating tab groups and tiling these groups to display at the same time. As their name would indicate, a tab group is a group of code editor window tabs, with each tab group appearing in a separate tile. Multiple tab groups can be created, limited only by the amount of screen real estate they occupy. You can choose to tile the tab groups vertically or horizontally; you cannot use a mix of the two.

To start this process, you drag a tab below or beside an existing one and dock it to achieve the same effect. This starts a new tab group and creates a tile for it (as shown in Figure 4-12).

You can drag tabs between tab groups or move them between tab groups using Window ➪ Move to Next Tab Group and Window ➪ Move to Previous Tab Group. These options are also available from the drop-down menu when right-clicking a tab.

To restore the user interface to having a single tab group again, move the tabs from the new tab groups back into the original one again and the tiling will be removed.

Advanced Functionality

To be a truly productive developer, it can help to know various advanced features available in the code editor that are hidden away but can save you a lot of time. Here are some of the most useful commands that aren’t immediately obvious within the code editor.

Block Selection

Also known as box selection, column selection, rectangle selection, or vertical text selection, block selection is the ability to select text in a block (as shown in Figure 4-13) instead of the normal behavior of selecting lines of text (stream selection). To select a block of text, hold down the Alt key while selecting text with the mouse, or use Shift+Alt+Arrow with the keyboard. This feature can come in handy when, for example, you have code lined up and want to remove a vertical portion of that code (such as a prefix on variable declarations).

Multiline Editing

Multiline editing extends the abilities of block selection. With block selection, after selecting a vertical block of text you can only delete, cut, or copy the block. With multiline editing you can type after selecting a vertical block of text, which will replace the selected text with what’s being typed on each line, as shown in Figure 4-14. This can be handy for changing a group of variables from readonly to const, for example.

Find All References

You can find where a method or property is called by right-clicking its definition and selecting Find All References from the drop-down menu, or placing the cursor in the method definition and pressing Shift+F12. This activates the Find All References window (see Figure 4-15) and displays the locations throughout your solution where that method or property is referenced.

The Find All References window has significantly changed in Visual Studio 2017. Where the references used to be in a flat list, you now have the ability to see them in a hierarchy. And you can change the default of Project then Definition by selecting one of the choices in the Group By combo box at the top center of the window. Or you can create your own grouping by right-clicking the results and using the Grouping option in the context menu.

You can then double-click a reference in the results window to navigate to that result in the code editor window. Or, if you just need to see a glimpse of the context for the reference, you can hover over the reference and the code around the reference appears as a tooltip.

Peek Definition

As you investigate code, there is frequently a need to quickly check on an invoked method. When you right-click the method and select Go to Definition from the context menu, the file containing the method opens and the method appears in the code editor. However, the file you were editing is no longer in focus. Although this is definitely not an insurmountable problem, it is an inconvenience.

The Peek Definition command enables developers to view the definition of a method without leaving their current editing context. Right-click the method as before, but select the Peek Definition option from the context menu. As shown in Figure 4-16, the method definition is visible, and a blue bar on the left side indicates the location of the method within the visible code.

Aside from allowing you to view the code, Peek Definition enables you to edit the code while you peek at it. And, while you hover over a method in the peek window, you can right-click and select Peek Definition to drill down into that method. When you are more than one level deep, a collection of blue and white circles appears (see Figure 4-17). Clicking on the circles enables you to easily navigate backward and forward through the call hierarchy.

Finally, if you want to promote the peeked file to the main editor window, there is a Promote to Document icon just to the right of the file name on the Peek Window tab.

Enhanced Scrollbar

The enhanced scrollbar, with its visual cues that provide information about the file that you are editing, is a very popular productivity tool. The visual cues include the location of errors and warnings, breakpoints, bookmarks, and search results. Figure 4-18 illustrates some of the different markers on the enhanced scrollbar.

The scrollbar in Visual Studio 2017 includes the Map mode feature, which is turned off by default. To enable it, you go to the Text Editor ➪ All Languages ➪ Scroll Bars node in the Tools ➪ Options dialog box, as shown in Figure 4-19. This particular node controls Map mode for every language. However, Map mode can be turned on or off for each language by going into the Scroll Bars node within the specific language.

In the Behavior section, a radio button allows you to toggle between the Vertical Scrollbar mode and the Map mode. When Map mode is enabled, you can also configure the preview tooltip and specify the size of the source code map (which also works out to be how wide the scrollbar is). Figure 4-20 shows the toolbar with all of these functions enabled.

A subtle feature is that Map mode is used wherever the code editor scrollbar exists. This includes the scroll bar in the Peek Definition screen.

The source code map is intended to provide a high-level, visual representation of the code that is being edited. You are not supposed to be able to make out the code itself — only the shape of the code is discernible. The intent is for this shape to assist you as you navigate through the file.

You can also see a preview tip. As you move your mouse up and down along the scrollbar (not click-dragging the mouse, but just hovering), a tooltip window appears that shows a preview of the code at the point where your mouse is (see Figure 4-21).

The idea behind the preview feature is to enable you to quickly recognize the code you are looking for without needing to scroll through the entire code window. Experientially, it works well for determining if your mouse is hovering over the part of the code you want to edit next. It is not really useful (nor is it intended to be) if you are looking for a particular variable or function. There are better ways to navigate through the code file for that purpose.

The capability to click to scroll is inherent in the preview window. As you are hovering over the different parts of your code file, you can change the view of the entire code window by clicking; for example, instead of moving the scrollbar handle up and down, you can click the position in the file you want to move to.

Structure Visualizer

On the opposite side of the code editor is the Structure Visualizer. This was a favorite feature from the Productivity Power Tools (a set of extensions to Visual Studio designed to improve the productivity of developers), and it has now been added to Visual Studio 2017. As you can see in Figure 4-22, there are a couple of faint, dotted vertical lines to the left of the code and to the right of the region expanders. There is one line for each level of contextual hierarchy in the code. For instance, in this example, the leftmost line is the namespace, the second line is the class and the third line is the method. When you hover over the line, the definition for all of the elements in the hierarchy (include any regions) appears as a tool tip. The goal of this feature is to give you an at-a-glance look at exactly where the code falls within the namespace/class/method hierarchy.

Navigate To

The design of the interface for Navigate To is intended to keep you “in the flow,” that is, among other things, to avoid forcing your hands to leave the keyboard. When you strike the appropriate keyboard chord (Ctrl+, is the default, but if that doesn’t work the Edit ➪ Navigate menu option is available), a small window appears in the top-right corner of the editor window, as shown in Figure 4-23.

As you start to type, Visual Studio uses a semantic search to display a list of matches. (In other words, instead of a straight text search, Visual Studio uses its understanding of the classes and methods in your code project as a relevancy guide.) Based on previous telemetry, the first item is the one you most commonly looked for previously, so it is automatically selected and the corresponding file appears as a preview. If you select another file (either by using the cursor or the mouse), that file is displayed in the preview tab. The Escape key closes the navigation window and puts you back to your original position.

At the top of the NavigateTo dialog is a toolbar that allows you to perform some basic filtering on the results. For instance, you can restrict the displayed items to Files, Symbols, Members, or Types. As well, you can modify the scope of the search so that it is limited to the current document or includes not just the current solution but also external dependencies. There is also a gear icon that lets you modify some settings for the Navigate To functionality. For instance, you can make the window appear in the top center instead of the top right. And you can toggle whether the Preview window is used when you click on an item.