VB.NET ASP.NET IsNumeric() Source Code Syntax Example

Posted by on Monday, February 28, 2011 · Leave a Comment 

IsNumeric Example Syntax VB.NET ASP.NET | IsNumeric | Source Code

Summary: – Illustrates using with in VB.NET ASP.NET.

 *** 1. Download Source Code *** 
VB.NET Syntax StringManipulation IsNumeric download Download Source Code for All VB ASP.NET Examples in One Project – source code for hundreds of VB.NET ASP.NET examples neatly organized in a single project.

 *** 2. IsNumeric Syntax *** 


Purpose:
Returns a Boolean value that indicates if the string is Null or Empty.


Syntax:
String.IsNullorEmpty(stringtocheck)

Parameters Description
stringtocheck Required – string that you want to check
whether it is null or empty

Result Data Type Description
Boolean Returns a Boolean value that indicates if the string is Null or Empty.


 *** 3. IsNumeric – Quick Example *** 
Dim strIsNullorEmptyExample As String = “This is a test string”
TextBox1.Text = String.IsNullOrEmpty(strIsNullorEmptyExample) ‘Returns False

 *** 4. IsNumeric – Full Example *** 

IsNumeric Example Output Screenshot


VB.NET Syntax StringManipulation IsNumeric screenshot


Step 1: Click on Visual Basic to Cut-n-paste code into IsNumeric.aspx.vb

Imports System
Imports System.IO
Imports System.Data
 
 
 
 
' This example is from http://idealprogrammer.com
' It shows how you can use IsNumeric syntax in VB.NET ASP.NET
'****************************************************************************************
' Purpose: Returns a Boolean value that indicates if the string is Null or Empty. 
'
' Syntax: 	String.IsNullorEmpty(stringtocheck)
'
' Parameter1: stringtocheck - Required - string that you want to check
' whether it is null or empty
'
' Result: Boolean -  Returns a Boolean value that indicates if the string is Null or Empty. 
'
' Quick Example:      Dim strIsNullorEmptyExample As String = "This is a test string"
' TextBox1.Text = String.IsNullOrEmpty(strIsNullorEmptyExample) 'Returns False
'
'****************************************************************************************
 
Partial Class _IsNumeric
    Inherits System.Web.UI.Page
 
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
 
        Label1.Text = "Example #1: IsNumeric(strField) "
 
        Dim strField As String = "100.00"
 
        TextBox1.Text = Microsoft.VisualBasic.IsNumeric(strField) 'Returns True - decimals are numeric
 
 
    End Sub
End Class

Step 2: Click on XML to Cut-n-paste code into IsNumeric.aspx

< %@ Page Language="VB" AutoEventWireup="false" CodeFile="IsNumeric.aspx.vb" Inherits="_IsNumeric" %>
 
< !DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <h1><asp:label ID="Label1" runat="server" Text="Label"></asp:label> </h1>
         <asp:textbox ID="TextBox1" runat="server"></asp:textbox><br />
          <h1><asp:label ID="Label2" runat="server" Text="Label"></asp:label> </h1>
         <asp:textbox ID="TextBox2" runat="server"></asp:textbox><br />
          <h1><asp:label ID="Label3" runat="server" Text="Label"></asp:label> </h1>
         <asp:textbox ID="TextBox3" runat="server"></asp:textbox><br />
 
 
 
    </div>
    </form>
</body>
</html>

Prerequistes:

  1. Install Visual Web Developer 2010
  2. Install SQL Server Express
  3. Download Northwind and Pubs Databases
  4. Attach Northwind Database to Databases in Sql Express
  5. Attach pubs Database to Databases in Sql Express

Notes:

  • You can build your own library of syntax examples by using same web site over and over and just add new web forms to it.

Instructions:

VB.NET ASP.NET Syntax StringManipulation IsNumeric
  1. Use Visual Web Developer 2010
  2. Create new web site;
    • Click File/New Web Site
    • Select ASP.NET Website Template
    • Select Visual Basic for Language
    • name of Web Site could be VBNET_ASPNET_Syntax.
  3. Add New folder named “StringManipulation”
    • Right-click project name in solution explorer;
    • add new folder;
    • name of folder could be: StringManipulation
  4. Add Web Form Named IsNumeric to StringManipulation folder
    • Right-click StringManipulation folder;
    • add new item;
    • Select Web Form
    • Check place code behind in separate file
    • Web Form name could be IsNumeric
  5. Click on Visual Basic in step 1 at the top of this page to copy code into code-behind IsNumeric.aspx.vb
  6. Click on XML in step 2 above to copy code into web form IsNumeric.aspx
  7. Right-click on IsNumeric.aspx in solution explorer and select view in browser

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