Summary of VB. NET syntax and vb.net syntax

Summary of VB. NET syntax and vb.net syntax

I am proficient in C # programming. I have no development experience in VB and need to perform project maintenance. I specially sorted out the VB syntax to make a negative supplement. All programming ideas are interconnected and are developed by Microsoft. The language is similar.

Imports System 1. (1) define a variable and initialize it. Dim strText As String = ""

Or Dim strText As String strText = ""

(2) instantiate a class or object Dim openFileDialog1 As New OpenFileDialog () Dim clsClass As New ClsClass () (3) declare an array Dim fileNames As String () = New String (3) {} fileNames (0) = "Zhang San" fileNames (1) = "Li Si" fileNames (2) = "Wang Wu"

(4) declare a generic type Dim list As New List (Of T) () II. Exception Handling.

Try Catch ex As Exception 

    Throw New Exception(ex.Message, ex)

 End Try 

Iii. Condition judgment statement

 If...Then... 

ElseIf...Then... 

Else ... End if 

Iv. Loop array and set

For i As Integer = 0 To openFileDialog1.FileNames.Length - 1 

//exit for 

Next 

For Each item In List           //exit for

 Next 

V. Process and Function

Public Sub function name (ByVal/ByRef parameter name As Integer) as type

End Sub 

Public Function Name (ByVal/ByRef parameter name As Integer) as type

'Vb6. 0: function writing with return values

 Dim str1 As String = "111" 

'Result = str1  

'You can also use the key value Return in vb.net to Return.

 Dim str2 As String = "222"

 Return str2 

End Function 

6. modules in vb.net are generally used only to define global variables and public methods.

Class ClassName 

Public shared Function fnXXX () as string' shared refers to the Static keyword equivalent to the Static keyword in C.

... 

End Function 

The End Class is called directly using ClassName. fnXXX. You can also call fnXXX () directly.

Module ModuleName 

public Function fnXXX() as string 

... 

End Function 

End Module

Call: ModuleName. fnXXX (). You can also call fnXXX () directly. There can be direct methods in the modules. These methods are automatically static (or shared-by-VB.. NET), these methods can be called directly, so the Module cannot be instantiated, there is no need to instantiate the Module can not inherit, and there can be classes in the interface Module, however, this class does not need to be referenced by the module as the prefix. Therefore, the concept module is a bit virtual and can be organized into the namespace. Because the module is actually virtual, its method can also be called directly in the outer namespace. 7. Use the same event for multiple identical events. VB. NET

Private Sub rdbFeedChannelAny_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rdbFeedChannel1.Click, rdbFeedChannel2.Click, rdbFeedChannel3.Click

 Exit Sub 

C#Designerthis.radioButton1.CheckedChanged += new System.EventHandler(radioButton_CheckedChanged);this.radioButton2.CheckedChanged += new System.EventHandler(radioButton_CheckedChanged)；Code； 

Private void radioButton_CheckedChanged (object sender, EventArgs e) {if (this. radioButton1.Checked) {}} 8. Overloads keywords to implement overload functions. Class1 Overloads Public Sub New () // constructor. ...... ...... End sub

Overloads Public Sub New(s as string) 　　。。。。。。 　　。。。。。。 　　end sub 

end Class 

9. withevents is used to declare an object. The object declared with withevents has its own event. When RaiseEvent exists in this object, it is received externally. Handles is used to receive the withevents object event. For example, if your object has an event A, and the RaiseEvent A object is executed, the SUB of the caller's handles object. A will be executed.