Guide to VB.Net: Advanced
Guide to VB.Net: Advanced
Viewing this guide means that you have viewed the intermediate tutorial. If you have not, go take a look at it. In this tutorial, you will learn how to extend upon what you already know to the point where it can be practically used in a useful application.
Part 1: Operators
Now, you probably already have recognized the standard operator of addition (+) but what are all the others? These operators will be essential to number based functions which you will need to create useful programs. The most common operators are listed below:
There are also inequality operators that we will need to know, these will be essential as well. Below are the most common inequality operators:
Part 2: Do Loop
I briefly explained the Do/Loop function in the last tutorial. Whatever is contained within the first line Do, and the final line Loop, will be repeated forever but sometimes forever isn't best. In order to Loop until a specific criteria is met, we can use the While or Until methods. The code below should explain:
Part 3: Accessing Data
In many cases, you will be in a situation where you will have multiple forms and you will need to access the data or even share the data amongst the forms. This can be done in different ways which are very simple.
The easy way into doing this is simply by adding a small piece of text to your code. Let's say you want to change the textbox in form2's text to something else. In order to do this, we could simple access it as shown below:
Part 4: Imports
For some odd reason, Microsoft thought it was a good idea to not automatically include everything in your project, so you have to Imports things to accomplish certain tasks. This is very simple, all you need to put is Imports and a Namespace to import into the project. Shown below is importing the Threading namespace. Without this threading imported, the Sleep code would not work and would result in an error.
It's just that simple, for programmers at this level, you will basically only need System.IO, System.Threading, and possibly System.Text if you're that good.
Part 5: e as Arguments
In most subs, there is all that crap you need in order to handle a function such as Button1 being clicked. If you look closely, e is always the constant declaration in them but what does it do? Lets test it out with a Web Browser control.
Part 6: Lesson Test
Now, your lesson test for this will be to put together an application that uses a lot of numerical functions. Make a Do/Loop that will increase the integer declared by any amount each time, and every time it's looped, make it complete a formula. Create a messagebox of the result of that formula and have the thread sleep for 2 seconds until the loop. Loop 5 times and then stop.
◄ Previous
Viewing this guide means that you have viewed the intermediate tutorial. If you have not, go take a look at it. In this tutorial, you will learn how to extend upon what you already know to the point where it can be practically used in a useful application.
Part 1: Operators
Now, you probably already have recognized the standard operator of addition (+) but what are all the others? These operators will be essential to number based functions which you will need to create useful programs. The most common operators are listed below:
- + Addition
- - Subtraction
- * Multiplication
- / Division
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim intDegreesF As Integer = 70
Dim intDegreesC As Integer
intDegreesC = (9 / 5) * intDegreesF + 32
End Sub
End ClassThere are also inequality operators that we will need to know, these will be essential as well. Below are the most common inequality operators:
- = Equals
- <> Not Equal
- < Less Than
- > Greater Than
- >= Greater Than or Equal To
- <= Less Than or Equal To
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim i As Integer = 3
If i > 5 Then
MsgBox("I is greater than 5")
ElseIf i <= 2 Then
MsgBox("I is less than (or is) 2")
ElseIf i = 6 Then
MsgBox("I is 6")
End If
End Sub
End ClassPart 2: Do Loop
I briefly explained the Do/Loop function in the last tutorial. Whatever is contained within the first line Do, and the final line Loop, will be repeated forever but sometimes forever isn't best. In order to Loop until a specific criteria is met, we can use the While or Until methods. The code below should explain:
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim i As Integer = 0
Do While i <= 10
MsgBox(i)
i = i + 1
Loop
End Sub
End ClassPublic Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim i As Integer = 0
Do Until i = 11
MsgBox(i)
i = i + 1
Loop
End Sub
End ClassPart 3: Accessing Data
In many cases, you will be in a situation where you will have multiple forms and you will need to access the data or even share the data amongst the forms. This can be done in different ways which are very simple.
The easy way into doing this is simply by adding a small piece of text to your code. Let's say you want to change the textbox in form2's text to something else. In order to do this, we could simple access it as shown below:
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim CString As String = "String Changed"
Form2.Textbox1.Text = CString
End Sub
End ClassModule Module1
Public String1 As String
End ModulePublic Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
String1 = "k"
End Sub
End ClassPart 4: Imports
For some odd reason, Microsoft thought it was a good idea to not automatically include everything in your project, so you have to Imports things to accomplish certain tasks. This is very simple, all you need to put is Imports and a Namespace to import into the project. Shown below is importing the Threading namespace. Without this threading imported, the Sleep code would not work and would result in an error.
Imports System.Threading
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
System.Threading.Thread.Sleep(5000)
End Sub
End ClassIt's just that simple, for programmers at this level, you will basically only need System.IO, System.Threading, and possibly System.Text if you're that good.
Part 5: e as Arguments
In most subs, there is all that crap you need in order to handle a function such as Button1 being clicked. If you look closely, e is always the constant declaration in them but what does it do? Lets test it out with a Web Browser control.
Public Class Form1
Private Sub WebBrowser1_DocumentCompleted(ByVal sender As System.Object, ByVal e As System.Windows.Forms.WebBrowserDocumentCompletedEventArgs) Handles WebBrowser1.DocumentCompleted
MsgBox(e.Url.AbsoluteUri)
End Sub
End ClassPart 6: Lesson Test
Now, your lesson test for this will be to put together an application that uses a lot of numerical functions. Make a Do/Loop that will increase the integer declared by any amount each time, and every time it's looped, make it complete a formula. Create a messagebox of the result of that formula and have the thread sleep for 2 seconds until the loop. Loop 5 times and then stop.
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