Practice # 5

Hashtables and Queues


1.

 Public Class Form1  
   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click  
     Dim str() As String = {"Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"}  
     For Each s As String In str  
       MsgBox(s)  
     Next  
   End Sub  
 End Class  

2.

 Public Class btnFirst  
   Dim info As New Hashtable  
   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click  
     info.Clear()  
     info.Add("First Name", txtFirst.Text)  
     info.Add("Last Name", txtLast.Text)  
     info.Add("E-mail", txtMail.Text)  
     txtFirst.Clear()  
     txtLast.Clear()  
     txtMail.Clear()  
   End Sub  
   Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click  
     MsgBox(info.Item("First Name"))  
   End Sub  
   Private Sub btnLast_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLast.Click  
     MsgBox(info.Item("Last Name"))  
   End Sub  
   Private Sub btnMail_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnMail.Click  
     MsgBox(info.Item("E-mail"))  
   End Sub  
 End Class  

3.

 Public Class frmPrinter  
   Dim print As New Queue  
   Private Sub btnSend_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSend.Click  
     Dim page As New Hashtable  
     page.Add("Title", txtTitle.Text)  
     page.Add("Pages", txtPages.Text)  
     print.Enqueue(page)  
     refreshJobs()  
   End Sub  
   Private Sub btnClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClear.Click  
     print.Dequeue()  
     refreshJobs()  
   End Sub  
   Private Sub refreshJobs()  
     lstQueue.Items.Clear()  
     For Each d As Hashtable In print  
       lstQueue.Items.Add(d.Item("Pages") & (" ") & d.Item("Title"))  
     Next  
   End Sub  
 End Class