The document discusses Visual Basic code for creating menus and menu items dynamically at runtime. It includes code to: 1) Add menu items to a runtime option menu by getting text values from textboxes and creating ToolStripMenuItems with that text. 2) Add click event handlers for the menu items that display a message box with the text of the clicked menu item. 3) Add a timer to a form and code to start, stop, and update a textbox with the elapsed time from the timer.

1. Visual Basic –User Interface-III
Visual Basic –User Interface-
IV
Govt. Polytechnic(W)
Faridabad
27th September 2016

9. Public Class Form1
Dim St, Mt1, MT2 As String
Dim Mb1, Mb2, Mt1ToolStripMenuItem, MT2ToolStripMenuItem As ToolStripMenuItem

10.  Private Sub Add_Menu_Click(sender As
Object, e As EventArgs) Handles
Add_Menu.Click
 Mt1 = TextBox2.Text
 MT2 = TextBox3.Text
 St = TextBox1.Text
 Dim Ab1, Ab2 As
ToolStripDropDownItem
 Mb1 = ColorToolStripMenuItem
 Mb2 = CalenderToolStripMenuItem
 Ab1 = Me.Mb2
 Ab2 = Me.Mb1

Me.RunTimeOptionToolStripMenuItem.Na
me = St

Me.RunTimeOptionToolStripMenuItem.Siz
e = New System.Drawing.Size(120, 22)

Me.RunTimeOptionToolStripMenuItem.Te
xt = St

Me.RunTimeOptionToolStripMenuItem.Dr
opDownItems.AddRange({Ab1, Ab2})
 End Sub
CODE

14.  Mt1 = TextBox2.Text
 MT2 = TextBox3.Text
 St = TextBox1.Text
 Dim Ab1, Ab2 As ToolStripDropDownItem
 Me.Mt1ToolStripMenuItem = New
System.Windows.Forms.ToolStripMenuItem()
 Me.Mt1ToolStripMenuItem.Name = Mt1
 Me.Mt1ToolStripMenuItem.Size = New System.Drawing.Size(120, 22)
 Me.Mt1ToolStripMenuItem.Text = Mt1
 Me.MT2ToolStripMenuItem = New
System.Windows.Forms.ToolStripMenuItem()
 Me.MT2ToolStripMenuItem.Name = MT2
 Me.MT2ToolStripMenuItem.Size = New System.Drawing.Size(120, 22)
 Me.MT2ToolStripMenuItem.Text = MT2
 Mb1 = Mt1ToolStripMenuItem
 Mb2 = MT2ToolStripMenuItem
 Ab1 = Me.Mb2
 Ab2 = Me.Mb1
 Me.RunTimeOptionToolStripMenuItem.Name = St
 Me.RunTimeOptionToolStripMenuItem.Size = New System.Drawing.Size(120,
22)
 Me.RunTimeOptionToolStripMenuItem.Text = St
 Me.RunTimeOptionToolStripMenuItem.DropDownItems.AddRange({Ab1,
Ab2})
 End Sub
Code

18.  Private Sub
Start_Timer_Click(sender As
Object, e As EventArgs) Handles
Start_Timer.Click
 TextBox1.Text = 0
 Timer1.Start()
 End Sub
 Private Sub Button1_Click(sender
As Object, e As EventArgs) Handles
Button1.Click
 Timer1.Stop()
 TextBox1.Text = TextBox1.Text
+ Timer1.Interval
 End Sub
Codes

21.  Private Sub Add_Menu_Click(sender As Object, e As EventArgs)
Handles Add_Menu.Click
 Mt1 = TextBox2.Text
 MT2 = TextBox3.Text
 St = TextBox1.Text
 Me.Mt1ToolStripMenuItem = New
System.Windows.Forms.ToolStripMenuItem()
 Me.Mt1ToolStripMenuItem.Name = Mt1
 Me.Mt1ToolStripMenuItem.Size = New
System.Drawing.Size(120, 22)
 Me.Mt1ToolStripMenuItem.Text = Mt1
 Me.MT2ToolStripMenuItem = New
System.Windows.Forms.ToolStripMenuItem()
 'Friend WithEvents Mt1ToolStripMenuItem As
ToolStripMenuItem
 'Friend WithEvents MT2ToolStripMenuItem As
ToolStripMenuItem
 Me.MT2ToolStripMenuItem.Name = MT2
 Me.MT2ToolStripMenuItem.Size = New
System.Drawing.Size(120, 22)
 Me.MT2ToolStripMenuItem.Text = MT2
 Mb1 = Mt1ToolStripMenuItem
 Mb2 = MT2ToolStripMenuItem
 Ab1 = Me.Mb1
 Ab2 = Me.Mb2
 Me.RunTimeOptionToolStripMenuItem.Name = St
 Me.RunTimeOptionToolStripMenuItem.Size = New
System.Drawing.Size(120, 22)
 Me.RunTimeOptionToolStripMenuItem.Text = St

Me.RunTimeOptionToolStripMenuItem.DropDownItems.AddRa
nge({Ab1, Ab2})
 End Sub

25.  Private Sub
Mt1ToolStripMenuItem_Click(send
er As Object, e As EventArgs)
Handles
Mt1ToolStripMenuItem.Click
 MsgBox("Menu Item 1" & " "
& Mt1ToolStripMenuItem.Text)
 End Sub
 Private Sub
MT2ToolStripMenuItem_Click(send
er As Object, e As EventArgs)
Handles
MT2ToolStripMenuItem.Click
 MsgBox("Menu Item 2" & " "
& MT2ToolStripMenuItem.Text)
 End Sub

28. Masked TextBox

33. .NET framework offers a
myriad of languages which
puts us programmers into a
deepthought process about
which programming
language best suits our
needs.

34. A variable is a named
memory location. They
are programming
elements that can
change during program
execution.
Data that needs to be
stored in memory &
accessed at a later time
are stored in variables.

35. All the primitive types
such as int, double etc
are value type
variables.
The simple types
basically consist of
Boolean and Numeric
types, where Numeric
is further divided into
Integral and Floating
Point.

36.  Object type or reference type
variables are those, which are
allocated storage space in the
heap.
 Reference type objects can be null.
When a reference type is allocated
under the covers a value is
allocated on the heap and a
reference to that value is returned.
 There are basically four reference
types:
 classes,
 interfaces,
 delegates
 arrays.

37.  Class type consists of custom user
defined data types such as the
Class Employee.
 Class Employee
 Dim empid As Integer
 Dim empname As String
 Public Sub New()
 empid = 10
 empname = "Reshmi"
 End Sub
 End Class

38.  Overloading provides the ability to
create multiple methods or
properties with the same name,
but with different parameters
lists.
 This is a feature of polymorphism.
It is accomplished by using the
Overloads keyword in VB.NET.

39.  Class test
Public Overloads Function Add(ByVal x As
Integer, ByVal y As
Integer)
Return x + y
End Function
Public Overloads Function Add(ByVal x As
String, ByVal y As
String)
Return x & y
End Function
Shared Sub main()
Dim a As new test
Dim b As Integer
Dim c As String
b = a.Add(1, 2)
c = a.Add("Reshmi", " Nair")
System.Console.Writeline(b)
System.Console.Writeline(c)
End Sub
End Class

40. In VB.NET by using
the Overridable
keyword with the
base class method
and the Overrides
keyword with the
derived class
method.

41.  Public Class shapes
 Public Overridable Sub display()
 Console.WriteLine("Shapes")
 End Sub
 End Class
 Public Class square
 Inherits shapes
 Public Overrides Sub display()
 Console.WriteLine("This is a
square")
 End Sub
 End Class
 Public Class rectangle
 Inherits shapes
 Public Overrides Sub display()
 Console.WriteLine("This is a
rectangle")
 End Sub
 End Class

42. Properties are named members
of classes, structs, and
interfaces.
They provide a flexible
mechanism to read, write, or
compute the values of private
fields through accessors.

43.  Structures are very similar to classes but there are
some restrictions present in the case of structures
that are absent in the case of classes.
 A structure allows to create own custom data
types and it contains one or more members that
can be of different data types.

44.  Namespaces are used in .Net to organize class libraries
into a hierarchical structure and reduce conflicts
between various identifiers in a program.
 Namespaces enables reusable components from
different companies to be used in the same program
without the worry of ambiguity caused by multiple
instances of the same identifier.
 Namespaces provide a logical organization for
programs to exist. Starting with a top level namespace,
sub-namespaces are created to further categorize
code, based upon its purpose.

45.  The base class library begins at the System namespace.
 Nested namespaces within the System namespace are
 System.Security
 System.IO
 System.Data
 System.Collection

46.  Boxing is the implicit conversion of a
 Value type to a reference type or
 To any interface type implemented by this value type.
 When boxing occurs, the contents of value type are
copied from the stack into the memory allocated on the
managed heap.
 The new reference type created contains a copy of the
value type and can be used by other types that expect
an object reference.

47.  UnBoxing is the explicit conversion from
 A reference type to a value type or
 From an interface type to a value type that implements
the interface.

48.  VB.Net does not support the
ability to explicitly unbox values.
 It relies on the helper functions in
the Microsoft.VisualBasic.Helpers
namespace to carry out unboxing.

49.  Enumerations are types that inherit from
System.Enum.
 The elements of an enumeration are expressed in
words rather than numbers, which makes it
convenient for understanding the meaning of the
value being used.
 Enumerations symbolically represent a set of values
of one of the primitive integral types.

50.  The type of the elements of an
enumeration can be Byte, Short,
Integer or Long.
 If no type is specified explicitly,
the default type is Integer.
Enumeration
Type

51.  The runtime supports constructs called delegates, which enable late-
bound operations such as method invocation and callback procedures.
 With delegates, a program can dynamically call different methods at
runtime.
 They are type safe, secure, managed objects that always point to a
valid object and cannot corrupt the memory of another object.
 The closest equivalent of a delegate in other languages is a function
pointer, but whereas a function pointer can only reference Shared
functions, a delegate can reference both Shared and instance
methods.
 Delegates are Marshal by Value Objects.
 The members of a delegate are the members inherited from class
System.Delegate.
 A delegate defines the signature and return type of a method. The
resulting delegate can reference any method with a matching
signature.
 Each instance of a delegate can forward a call to one or more methods
that take those parameters and return the same type.
 Once a method has been assigned to a delegate, it is called when the
delegate is invoked.

52.  When ByVal keyword is used, it causes the parameter to be passed
by value.
 In this case, a copy of the original parameter is passed to the called
module.
 Thus any changes made to the copy of the parameter do not affect
the original value of the parameter.

53.  When ByRef keyword is used, it sends a reference (pointer) to the
original value to the called module rather than its copy.
 Thus any changes made to the parameter in the
function/procedure will cause the original value to be modified.

54.  Ctype is a general cast keyword that coerces an expression into
any type.
 It returns the result of explicitly converting an expression to a
specified data type, object, structure, class, or interface.
 If no conversion exists from the type of the expression to the
specified type, a compile-time error occurs.
 When Ctype is used to perform explicit conversion, execution is
faster since it is compiled inline and hence no call to a procedure
is involved to perform the conversion.

55. Integer Type VB.NET CLR Type
 8-bit Integer Byte System.Byte
 16-bit Integer Short System.Int16
 32-bit Integer Integer System.Int32
 64-bit Integer Long System.Int64

57.  The .NET Framework provides a run-time environment called the
Common Language Runtime, which manages the execution of code
and provides services that make the development process easier.

58.  Compilers and tools expose the
runtime's functionality and enable
you to write code that benefits
from this managed execution
environment.
 Code developed with a language
compiler that targets the runtime
is called managed code.

59.  dotNET Tutorial for Beginners,
India Community Initiative
 Microsoft Visual Studio 2010
byMichael Halvorson, Microsoft
 Microsoft Visual Basic 6.0 by
Francesco Balena ,Microsoft Press

60. THANK YOU