Most likely, you have existing Web applications that you have developed with development environments other than Visual Studio .NET. For example, before upgrading to Visual Studio .NET, you might have used Microsoft’s Visual InterDev or FrontPage, Macromedia’s Dreamweaver or HomeSite, or even Notepad.

How do you take an existing Web application and use Visual Studio .NET to edit it? You have two choices—migrate or upgrade.

The first choice is to migrate an existing Web application to a new Visual Studio .NET application. In this case, you create a new Visual Studio .NET application on your Web server and then you copy existing files to the new application. To do this, perform the following steps:

The advantage of using this first method of migrating an old application to a new Visual Studio .NET application is that you automatically get all the supporting ASP.NET Web application files. When you create a new project, all the configuration files are created for you.

The disadvantage of this first method is that it requires you to create a new location for your Web application. You must create a new folder on your Web server and migrate all of the old application files to it.

Instead of creating a new folder on your Web server, you can create a new project in an existing folder. To do this, perform the following steps:

The disadvantage of using the New Project in Existing Folder template to upgrade an application is that it does not automatically create the supporting ASP.NET Web application configuration files for you. For example, if you need to use the Web.Config file, you need to manually add the file yourself.

Imagine that you are called to a meeting in Paris to demonstrate your newest Web application. You book a flight on the Concorde and get ready to go. Unfortunately, you remember at the last minute that your application has one little bug. What do you do?

Visual Studio .NET supports building Web applications offline. You can create a local copy of the files from a Web application on your local machine, modify the files, and then resynchronize the files with the Web server when you go online again. Consequently, you can leap on the Concorde with your laptop, make the modifications in the air, and update the Web server when you land in Paris.

To switch a project to offline mode, open the Project menu, point to Web Project, and select Work Offline (see Figure 1.3). When you do this, all the files from the Web server are copied to your computer. By default, the files are added to the VSWebCache folder on your computer.

Figure 1.3. Selecting offline mode.

While working offline, you can continue to open the files in your application in a Web browser. You’ll notice that the files are no longer served from your Web server. They are opened from an offline folder. To use offline mode, you need to have Internet Information Services running on your local computer.

After you have connected to the network, you can go back online by opening the Project menu, pointing to Web Project, and unchecking Work Offline. Your files should be automatically resynchronized with the files on the remote Web server. When you are back online, you can also manually resynchronize files by opening the Project menu, pointing to Web Project, and selecting Synchronize All Folders.

You can add files and folders to a project by right-clicking an existing project or folder in the Solution Explorer window and selecting a type of item to add. For example, to add a new folder to your Web application, you would right-click an existing project and choose Add, New Folder.

You can also use Solution Explorer to add already existing items to a project. For example, if you want to add a cool GIF image that you created with Photoshop to your application, you would right-click the folder to which you want to add the image file and select Add, Add Existing Item. Next, you would browse to your image on your local hard drive, select it, and click OK to copy the image to the Web application.

An alternative method of adding existing items to Solution Explorer is to simply drag and drop the item from your desktop into the Solution Explorer window. If you prefer to not drag and drop the item, you can also right-click the item on your desktop, click Copy, right-click a folder in Solution Explorer, and click Paste.

Suppose that you need to move a file in your application from one folder to another. There are two ways that you can move items with Solution Explorer. First, you can simply drag and drop the item from one folder to another. To do this, just click the item, keep your mouse button pressed, and move your mouse until the mouse cursor hovers over the new folder. When you release the button, the item is copied.

Alternatively, you can right-click an item, choose Cut, right-click the new folder, and choose Paste. If you want to create a new copy of an item, simply choose Copy instead of Cut when selecting the item.

By default, the items under each tab in the Toolbox are displayed in a list. If you have a lot of items to display beneath a particular tab, you might want to disable list view (see Figure 1.11). To disable list view, right-click the Toolbox and uncheck List View.

Figure 1.11. List view disabled.

You can also arrange the order in which the items in the Toolbar are displayed. If you simply want to display the items in alphabetical order, right-click the Toolbar and select Sort Items Alphabetically.

If you want more fine-grained control over the order of the items in a Toolbar, you can arrange each item individually. Right-click a particular item and select either Move Up or Move Down. You can also drag and drop an item from one position on the Toolbar to another.

You can add a variety of different items to the Toolbox including new Web Server controls, components, and even HTML content and code snippets.

For example, imagine that you have just downloaded a new Web server control that you want to use in your applications. You can add this control to the Toolbar by right-clicking the Toolbar and selecting Customize Toolbox (alternatively, you can select Customize Toolbox from the Tools menu).

When you select Customize Toolbox, the dialog box in Figure 1.12 appears. This dialog box contains two tabs—a tab for adding COM components and a tab for adding .NET Framework components. Choose the .NET Framework Components tab and click the Browse button to browse to the Web server control on your computer.

Figure 1.12. Customizing the Toolbox.

After you click Open, the control should appear in the list of .NET Framework components. Select the check box next to the component and click OK, the new control should now appear in the Toolbox, just like all the standard controls.

You can extend the Toolbox with your own custom tabs. For example, you might want to add a new tab named My Favorite Controls that contains only third-party Web server controls. To add a new tab, right-click the Toolbar and select Add Tab. Next, enter a name for the new tab.

You can remove a tab that you have added by right-clicking the tab in the Toolbar and selecting Delete Tab. You can also right-click the tab and select Move Up or Move Down to modify the order of the tabs in the Toolbar.

The Navigation Bar appears at the top of the Code Editor. It contains two drop-down lists that enable you to quickly navigate to a previously declared method in your code.

When working with a C# project, the top-left drop-down list contains a list of types in the current page. The top-right drop-down list contains a list of members. For example, you can quickly navigate to a method by selecting a method from the Members drop-down list.

In a VB.NET project, the top-left drop-down list is labeled Class Name and the top-right drop-down list is labeled Method Name. You can navigate to an existing function or subroutine or add a new one by selecting the appropriate method name from the top-right drop-down list.

If you receive an error when executing an application and you know the line number of the error, you will need to quickly get to the right line of code in the Code Editor. To do this, you can use the Edit, Go To menu option. A dialog box appears that enables you to enter a line number.

You can right-click a variable, method, function, or subroutine and navigate directly to its declaration. To do this, right-click the item in the Code Editor and select Go to Definition.

Visual Studio .NET supports both basic and advanced text searching features. You can use the Find command to simply perform a search for text in the current document. The Find command also supports several advanced features, such as the ability to search through multiple documents, support for regular expression matches, and support for incremental searches.

To perform a basic search, simply enter your search text in the Find text box on the toolbar. Press Enter and your document will be searched.

To perform more advanced searches, open the Edit menu, point to Find and Replace, and select Find (see Figure 1.16). To find text in external files, open the Edit menu, point to Find and Replace, and select Find in Files (you can also click the Find in Files icon on the toolbar).

Figure 1.16. Opening the Find dialog box.

Finally, you can perform incremental searches. In an incremental search, text is matched as you type it. To perform an incremental search, open the Edit menu, point to Advanced, and choose Incremental Search. After you select this option, the cursor icon appears as a set of binoculars. If you enter text, the text is matched in the editor code document as you type.

You can bookmark any location in a code document and return to it later. To add a bookmark, click the bookmark icon on the toolbar (it looks like a blue flag). After you add a bookmark, a light blue box appears next to the code line (see Figure 1.17).

Figure 1.17. Adding a bookmark.

To return to a bookmark, you can use one of two additional bookmark icons on the toolbar. The Move the Caret to the Next Unnamed Bookmark icon navigates to the next bookmark in the document. The Move the Caret to the Previous Unnamed Bookmark icon navigates to the previous bookmark in the document.

By default, when you open a new document to edit with the Code Editor, a new tab appears at the top of the Code Editor. You can switch between open windows by clicking the tabs. The default view mode for Visual Studio .NET is called Tabbed Documents mode.

If you prefer, you can use Multiple Document Interface (MDI) mode instead. When MDI mode is enabled, you can tile multiple windows on the screen at the same time (see Figure 1.18).

Figure 1.18. Viewing the Code Editor in MDI mode.

To switch from Tabbed Documents mode to MDI mode, perform the following steps:

This change does not take effect until you shut down and restart Visual Studio .NET.

You can use any font, foreground color, and background color with the Code Editor that you want. For example, Figure 1.19 shows the Code Editor with a blue background and a 24pt Script font.

Figure 1.19. Customizing the Code Editor font.

To change the font and background color of the Code Editor window, perform the following steps:

If you want to return these options to their default values, click the Use Defaults button.

You can display line numbers in the left margin of the Code Editor (see Figure 1.20). To enable line numbering, perform the following steps:

Figure 1.20. Displaying line numbers.

After you complete these steps, line numbers will appear in the Code Editor window.

If you need to settle down and write a long page of code, it’s nice to be able to switch to full screen mode. In full-screen mode, all the windows and toolbars are hidden except for the Code Editor window (see Figure 1.21).

Figure 1.21. Using full-screen mode.

To enable full-screen mode, press the key combination Alt+Shift+Enter. You can return to normal mode either by pressing Alt+Shift+Enter again or by clicking the full-screen icon in the full-screen window.

By default, the Task List window displays tasks associated with all the files in a project. For example, if you have multiple Web Form Pages in a project, the tasks associated with all the pages appear in the Task List window. However, you might want to focus on only those tasks associated with the file currently opened in the Code Editor.

To display only those tasks associated with the current file displayed in the Code Editor, open the View menu, point to Show Tasks, and select Current File.

You can automatically add entries to the Task List by using particular keywords when adding comments to your code. For example, suppose that you add the following comment to your code:

C#. 

// TODO: Must add a subroutine here

VB.NET. 

' TODO: Must add a subroutine here

The special keyword TODO causes a new entry to automatically be added to the Task List. Notice that the TODO keyword appears in the context of a comment.

When you click the TODO entry in the Task List window, you are brought the correct line in the Code Editor window. To display all comment tasks, select View, Show Tasks, Comment.

You can add your own keywords that will automatically trigger the addition of tasks to the Task List. For example, you might want to add a keyword SLOPPY that indicates a sloppily written section of code.

To add a custom keyword, perform the following steps:

After completing these steps, the comment will automatically appear in the Task List whenever you use the keyword SLOPPY.

When there are errors in your code, the errors are automatically added as tasks to the Task List window. Some errors are added to the Task List before the code is compiled. These errors are added to the Task List as you type. Other errors are added after the code is compiled.

For example, if you start using a variable named strMessage in your code and you neglect to declare it, an entry is automatically added to the Task List warning you of this fact.

You can view all the errors in the Task List by opening the View menu, pointing to Show Tasks, and selecting Build Errors, or by opening the View menu, pointing to Show Tasks, and selecting All. From the Task List window, you can click a particular error entry and navigate directly to the appropriate section of code.

You might want to add custom tasks to the Task List. For example, if you have a list of future changes that you plan to make to an application, you can add these proposed changes to the Task List.

To add a new user entry to the Task List, open the View menu, point to Show Tasks, and select User, or open the View menu, point to Show Tasks, and select All.

To add a new task, click the section of the Task List window that reads Click Here to Add a New Task. When you add a new task, you can specify the task priority and enter a description of the task.

After you complete the task, you can check the check box next to the task. Checking the check box next to a user task causes the task description to appear with a line through it (it strikes out the task).

You can use the Task List window to maintain a list of shortcuts to sections of code. This works somewhat like adding a bookmark to your code. However, items added to the Task List are more permanent and they can have descriptions.

To open the Shortcut Task List window, open the View menu, point to Show Tasks, and select Shortcut, or open the View menu, point to Show Tasks, and select All.

To add a new shortcut to the Shortcut Task List window, right-click a line of code in the Code Editor and select the Add Task List Shortcut option. Alternatively, you can open the Edit menu, point to Bookmarks, and select Add Task List Shortcut.

After you add a shortcut to the Task List menu, you can navigate to the corresponding section of code in the Code Editor simply by double-clicking the shortcut.