Stair Of DotNET: 2014

Wednesday 23 July 2014

asp.net 13: dropdown list(auto postback)

program to select roll number and display name vice versa using auto post back property.

-----------------------------------------DESIGN-----------------------------------------------------

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<title>Untitled Page</title>

</head>

<body>

<div>

<asp:Label ID="Label1" runat="server" ForeColor="Red"

Text="DEMO OF AUTOPOSTBACK PROPERTY"></asp:Label>

<br />

<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True">

<asp:ListItem>Select Enrollment No</asp:ListItem>

<asp:ListItem>1</asp:ListItem>

<asp:ListItem>2</asp:ListItem>

<asp:ListItem>3</asp:ListItem>

<asp:ListItem>4</asp:ListItem>

<asp:ListItem>5</asp:ListItem>

<asp:ListItem></asp:ListItem>

</asp:DropDownList>

<br />

</div>

<asp:DropDownList ID="DropDownList2" runat="server" AutoPostBack="True"

Height="38px" Width="148px">

<asp:ListItem>Select Name</asp:ListItem>

<asp:ListItem>Meru</asp:ListItem>

<asp:ListItem>Johar</asp:ListItem>

<asp:ListItem>sanjay</asp:ListItem>

<asp:ListItem>Akshay</asp:ListItem>

<asp:ListItem>Nikunj</asp:ListItem>

</asp:DropDownList>

<br />

<asp:Button ID="Button1" runat="server" Text="OK" />

<br />

<asp:ListBox ID="ListBox1" runat="server" Height="126px" Width="145px">

</asp:ListBox>

</form>

</body>

</html>

-----------------------------------------code---------------------------------------------------------

Partial Class _Default

Inherits System.Web.UI.Page

Dim a As Integer

Dim b As Integer

Protected Sub DropDownList1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DropDownList1.SelectedIndexChanged

a = DropDownList1.SelectedIndex

DropDownList2.SelectedIndex = a

ListBox1.Items.Clear()

End Sub

Protected Sub DropDownList2_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DropDownList2.SelectedIndexChanged

b = DropDownList2.SelectedIndex

DropDownList1.SelectedIndex = b

ListBox1.Items.Clear()

End Sub

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

ListBox1.Items.Add("Enrollment No:" & DropDownList1.SelectedItem.ToString())

ListBox1.Items.Add("Name:" & DropDownList2.SelectedItem.ToString())

End Sub

End Class
-----------------------------------------output----------------------------------------------------

codestrew

Saturday 7 June 2014

program 23: interface

program to demonstrate concept of interface.

-----------------------------------------code---------------------------------------------------------

Imports System.Console

Module Module1

Sub Main()

Dim obj1 As New one

Dim obj2 As New two

obj1.disp()

obj1.multiply()

obj2.disp()

obj2.multiply()

ReadKey()

End Sub

End Module

Public Interface test

Sub disp()

Function multiply() As Double

End Interface

Public Class one

Implements test

Public i As Double = 12

Public j As Double = 12.17

Public Sub disp() Implements test.disp

WriteLine("sum=" & i + j)

End Sub

Public Function multiply() As Double Implements test.multiply

WriteLine("muliplication=" & i * j)

End Function

End Class

Public Class two

Implements test

Public a As Double = 20

Public b As Double = 32.17

Public Sub disp() Implements test.disp

WriteLine("Welcome to interface")

End Sub

Public Function multiply() As Double Implements test.multiply

WriteLine("multiplication=" & a * b)

End Function

End Class
-----------------------------------------output----------------------------------------------------

codestrew

program 22: abstract class

program to demonstrate concept of abstract and not inheritable class.

-----------------------------------------code---------------------------------------------------------

Imports System.Console

Module Module1

Public MustInherit Class abstractclass

Public MustOverride Function add() As Integer

Public MustOverride Function mul() As Integer

End Class

Public Class abstractone

Inherits abstractclass

Dim i As Integer = 20

Dim j As Integer = 30

Public Overrides Function add() As Integer

Return i + j

End Function

Public Overrides Function mul() As Integer

Return i * j

End Function

End Class

Sub Main()

Dim a As New abstractone

WriteLine("sum is:" & a.add())

WriteLine("multiplication is:" & a.mul())

ReadKey()

End Sub

End Module
-----------------------------------------output----------------------------------------------------

codestrew

program 21: base class construction

program to demonstrate concept of base class construction.

-----------------------------------------code---------------------------------------------------------

Imports System.Console

Module Module1

Sub Main()

Dim w As New window(10, 5)

w.drawwindow()

Dim lb As New listbox(20, 30, "hello..!!")

lb.drawwindow()

Console.ReadKey()

End Sub

End Module

Public Class window

Private top As Integer

Private left As Integer

Public Sub New(ByVal top As Integer, ByVal left As Integer)

Me.top = top

Me.left = left

End Sub

Public Sub drawwindow()

WriteLine("Drawing window at {0},{1}", top, left)

End Sub

End Class

Public Class listbox

Inherits window

Public Sub New(ByVal top As Integer, ByVal left As Integer, ByVal tcontent As String)

MyBase.New(top, left)

mlstboxcontent = tcontent

End Sub

Public Shadows Sub drawwindow()

Console.WriteLine("..........")

MyBase.drawwindow()

Console.WriteLine("Writing string to the listbox:{0}", mlstboxcontent)

End Sub

Private mlstboxcontent As String

End Class
-----------------------------------------output----------------------------------------------------

codestrew

program 20: inheritance

program to demonstrate concept of inheritance.

-----------------------------------------code---------------------------------------------------------

Module Module1

Class A

Public Sub Show()

Console.WriteLine("Calling from A")

End Sub

End Class

Class B

Inherits A

Public Shadows Sub Show()

Console.WriteLine("Calling from B")

End Sub

End Class

Class C

Inherits B

Public Shadows Sub Show()

Console.WriteLine("Calling from C")

End Sub

End Class

Public Sub Main()

Dim x As New A

x.Show()

Dim y As New B

y.Show()

Dim p1 As New C

p1.Show()

Console.ReadKey()

End Sub

End Module
-----------------------------------------output----------------------------------------------------

codestrew