How to Create a Website URL Verifier in Visual Basic

Submitted by GeePee on Thursday, April 23, 2015 - 23:01.
Introduction: Welcome to a tutorial on how to create a website/url verifier and checker in Visual Basic. Steps of Creation: Step 1: First we want to create a form with a textbox to contain the website url, button1 to verify the url format and button2 to check the website response. Step 2: First lets make a function to check the url and return the correctly formatted url.
  1. Private Function doCheck(ByVal s As String)
  2.     If (s.StartsWith("http://www.") Or s.StartsWith("https://www.")) Then
  3.         Return s
  4.     ElseIf (s.StartsWith("http://")) Then
  5.         If (s.Contains("www.")) Then
  6.             s = "http://www." & s.Substring(1, s.Count - 1)
  7.             TextBox1.Text = s
  8.             Return s
  9.         Else
  10.               s = "http://www." & s.Substring(7, s.Count - 7)
  11.             TextBox1.Text = s
  12.             Return s
  13.          End If
  14.       ElseIf (s.StartsWith("https://")) Then
  15.         If (s.Contains("www.")) Then
  16.             s = "https://" & s.Substring(12, s.Count() - 12)
  17.             TextBox1.Text = s
  18.             Return s
  19.          Else
  20.               s = "https://www." & s.Substring(8, s.Count - 8)
  21.              TextBox1.Text = s
  22.             Return s
  23.         End If
  24.      Else
  25.         If (s.StartsWith("www.")) Then
  26.             s = "http://www." & s.Substring(4, s.Count() - 4)
  27.              TextBox1.Text = s
  28.             Return s
  29.           Else
  30.               s = "http://www." & s
  31.             TextBox1.Text = s
  32.             Return s
  33.         End If
  34.     End If
  35. End Function
Step 3: Next lets run the function on button1 click...
  1. Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
  2.     Dim s As String = TextBox1.Text.ToLower()
  3.     TextBox1.Text = doCheck(s)
  4. End Sub
Step 4: Now for the response checker. We simply try to get a response, if it fails it will also fail the try statement and output that the website is un-responsive.
  1. Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
  2.     Try
  3.         Dim r As httpwebrequest = httpwebrequest.create(TextBox1.Text)
  4.         Dim re As httpwebresponse = r.getresponse()
  5.         MsgBox("Website responsive.")
  6.     Catch ex As Exception
  7.         MsgBox("Website un-responsive.")
  8.     End Try
  9. End Sub
Project Complete! That's it! Below is the full source code and download to the project files.
  1. Imports System.Net
  2. Public Class Form1
  3.     Private Function doCheck(ByVal s As String)
  4.         If (s.StartsWith("http://www.") Or s.StartsWith("https://www.")) Then
  5.             Return s
  6.         ElseIf (s.StartsWith("http://")) Then
  7.             If (s.Contains("www.")) Then
  8.                 s = "http://www." & s.Substring(1, s.Count - 1)
  9.                 TextBox1.Text = s
  10.                 Return s
  11.             Else
  12.                 s = "http://www." & s.Substring(7, s.Count - 7)
  13.                 TextBox1.Text = s
  14.                 Return s
  15.             End If
  16.         ElseIf (s.StartsWith("https://")) Then
  17.             If (s.Contains("www.")) Then
  18.                 s = "https://" & s.Substring(12, s.Count() - 12)
  19.                 TextBox1.Text = s
  20.                 Return s
  21.             Else
  22.                 s = "https://www." & s.Substring(8, s.Count - 8)
  23.                 TextBox1.Text = s
  24.                 Return s
  25.             End If
  26.         Else
  27.             If (s.StartsWith("www.")) Then
  28.                 s = "http://www." & s.Substring(4, s.Count() - 4)
  29.                 TextBox1.Text = s
  30.                 Return s
  31.             Else
  32.                 s = "http://www." & s
  33.                 TextBox1.Text = s
  34.                 Return s
  35.             End If
  36.         End If
  37.     End Function
  38.     Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
  39.         Dim s As String = TextBox1.Text.ToLower()
  40.         TextBox1.Text = doCheck(s)
  41.     End Sub
  42.  
  43.     Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
  44.         Try
  45.             Dim r As httpwebrequest = httpwebrequest.create(TextBox1.Text)
  46.             Dim re As httpwebresponse = r.getresponse()
  47.             MsgBox("Website responsive.")
  48.         Catch ex As Exception
  49.             MsgBox("Website un-responsive.")
  50.         End Try
  51.     End Sub
  52. End Class
Tags
visual basic
vb
.NET
Website
url
Verifier
Checker
Response