Home > Articles > Programming > Windows Programming

  • Print
  • + Share This
Like this article? We recommend

Like this article? We recommend

Creating Your First VB.NET Application

You have an open project with one form in it. So far, you haven't done anything to it, so you now need to create the obligatory "Hello World" application. I remember when Microsoft was running around showing the world how you could create a "Hello World" application in VB by typing just one line of code. Well, it's still that easy, but things sure look different now.

Make sure that your form is showing in the work area, and open the Toolbox. Click and drag a button onto the form. Place it wherever you want. So far, this is just like VB6. Now double-click on the button.

Double-clicking on the button causes the code window to open, but it is now just a tab in the work area. The new tab is labeled Form1.vb. You have a lot of code in this window, and it's code that you haven't seen before. In fact, before typing any code at all, you have the code shown in Figure 10. Notice that I have turned on line numbers just for easier referencing. If you want to turn on line numbers as well, go to Tools, Options. Expand the Text Editor node and choose Basic. Check the Line Numbers check box.

Figure 10 The code window shows a significant amount of code before you even start typing.

The first three lines of code are all Imports statements. The Imports statement is what you use to bring in a namespace from a referenced assembly. For now, just think of the namespace as a library of functions.

After the namespaces are imported, you have a public class for Form1. Notice that all the code is inside the Form1 class. Why? Because forms are really just classes, and they have been forever. You might not have ever thought of it that way, but a form is just another class. When a form is displayed, you have just instantiated a class.

Inside the class, the first thing you see is an Inherits statement. This is your first indication of true inheritance in VB.NET. This form is inheriting from the base System.WinForms.Form class. Therefore, System.WinForms.Form holds the true definition of a form, with its properties, methods, and events. You can inherit from this base class and then extend it if you want to do so.

The next piece inside the class is a public sub named New. Notice that it calls a sub named InitializeComponent. The InitializeComponent routine is not immediately seen, but you'll see it in just a moment. The New routine is similar to the Form_Load event procedure you got used to in VB6. Notice that you need to add any of your own code after the call to InitializeComponent.

After the New sub is a Dispose sub, much like the Form_Unload found in VB6. This is the area for the cleanup of anything you might have open. Don't worry about the Overrides keyword for now; it will be covered when you learn more about inheritance.

Next is where things start to get interesting. A gray line runs down the left side of the code, with minus signs at the Class and Sub definitions. Notice that under the Dispose sub is some text that says Windows Form Designer generated code with a plus sign next to it. If you click on that plus sign, you will expand a block of code that is normally collapsed. One thing that the VB.NET editor lets you do is to collapse or expand blocks of code. This can make it easier to see a cleaner view of your code. If you expand the code at line 26 (at least that's the line in Figure 10), you will see a code region and in it you'll see the InitializeComponent sub. In fact, the entire region of code is shown in Listing 1.

NOTE

All this code looks different in Beta 2. Code still sets up the form and the controls, but it has changed. Don't worry about exactly how the code looks, but instead focus on the fact that it exists and understand what it does at a high level.

Listing 1: Code Generated for You by the Windows Form Designer

#Region " Windows Form Designer generated code "

  'Required by the Windows Form Designer
  Private components As _
   System.ComponentModel.Container
  Private WithEvents Button1 As _
   System.WinForms.Button

  Dim WithEvents Form1 As System.WinForms.Form

  'NOTE: The following procedure is required by
  'the Windows Form Designer
  'It can be modified using the Windows
  'Form Designer.
  'Do not modify it using the code editor.
  Private Sub InitializeComponent()
    Me.components = New _
     System.ComponentModel.Container()
    Me.Button1 = New System.WinForms.Button()

    '@design Me.TrayHeight = 0
    '@design Me.TrayLargeIcon = False
    '@design Me.TrayAutoArrange = True
    Button1.Location = New _
     System.Drawing.Point(96, 40)
    Button1.Size = New System.Drawing.Size(75, 23)
    Button1.TabIndex = 0
    Button1.Text = "Button1"

    Me.Text = "Form1"
    Me.AutoScaleBaseSize = New _
     System.Drawing.Size(5, 13)

    Me.Controls.Add(Button1)
  End Sub

#End Region

As you can see, the InitializeComponent routine is in this normally collapsed block, and it is what sets up the controls on the form. Notice that the button has properties set, such as the location and size, and then is added to a controls collection.

Finally, below this region of code is the routine to handle the click event on the button. This looks different from what you have seen before as well. In fact, if you started a new Standard EXE project in VB6, added a button to the form, and then double-clicked the button, your entire project would just show this code:

Private Sub Command1_Click()

End Sub

However, in VB.NET, you will see a lot more code. In fact, the Click event is not even handled until line 57, at least in this example. The declaration of the event procedure is quite different as well. In VB.NET, the event procedure looks like this:

Protected Sub Button1_Click(ByVal sender As Object, _
   ByVal e As System.EventArgs)

End Sub

NOTE

Event procedures have changed in Beta 2. They will all require a Handles clause in Beta 2 and beyond.

Again, don't worry about all the changes for now. Instead, type in the following line of code:

msgbox "Hello, World"

When you move off this line, you will notice that VB.NET automatically adds parentheses around your argument, leaving you with this:

msgbox("Hello, World")

This is one of the first fundamental language changes: Subs and functions require parentheses around the argument. The msgbox command is a function, but in VB6, you did not need parentheses around a parameter if you were ignoring the return value. In VB.NET, you always need the parentheses, so get used to adding them, or at least get used to seeing VB.NET add them for you.

Now it is time to run this rather exciting demonstration and see whether it works. You can click the Start button on the toolbar (it should look familiar), or you can go to the Debug menu and choose Start.

Form1 should load. Click on the button, and you should get a message box to pop up, with the text "Hello, World." However, as you can see in Figure 11, the title of the message box is Error. That's new and certainly not welcome. Close the form and return to the VB.NET IDE.

NOTE

Beta 2 has changed how message boxes work, and the word Error is no longer present in the title. Instead, the title is the name of the application.

The Hello World application running.

Notice that a new window is showing. At the bottom of the screen, an Output window is now open. Figure 12 shows this window. Currently, it shows you all the debug statements. You did not put any debug.print statements into your code, but certain actions by the complier automatically put comments into the debug window.

Figure 12 The new debug window.

Before moving on, you might want to fix the Error in the title of the message box. Return to the one line of code you've written so far, and modify it to look like this:

msgbox("Hello, World", , "My first VB.NET App")

Now that you have added a title to the message box, run the project again, and your message box will have My First VB.NET App as its title. If you think it doesn't get any better than this, hang on.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020