VB.Net/GUI/ComboBox

Get selected Item from ComboBox

<source lang="vbnet"> Imports System.Windows.Forms

Module Module1

   Sub Main()
       Application.Run(New Form1)
   End Sub

End Module

Public Class Form1

   Inherits System.Windows.Forms.Form

1. Region " Windows Form Designer generated code "

   Public Sub New()
       MyBase.New()
       "This call is required by the Windows Form Designer.
       InitializeComponent()
       "Add any initialization after the InitializeComponent() call
   End Sub
   "Form overrides dispose to clean up the component list.
   Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
       If disposing Then
           If Not (components Is Nothing) Then
               components.Dispose()
           End If
       End If
       MyBase.Dispose(disposing)
   End Sub
   "Required by the Windows Form Designer
   Private components As System.ruponentModel.IContainer
   "NOTE: The following procedure is required by the Windows Form Designer
   "It can be modified using the Windows Form Designer.  
   "Do not modify it using the code editor.
   Friend WithEvents ComboBox1 As System.Windows.Forms.ruboBox
   Friend WithEvents Button1 As System.Windows.Forms.Button
   <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
       Me.ruboBox1 = New System.Windows.Forms.ruboBox()
       Me.Button1 = New System.Windows.Forms.Button()
       Me.SuspendLayout()
       "
       "ComboBox1
       "
       Me.ruboBox1.Items.AddRange(New Object() {"A", "B", "C", "D", "E"})
       Me.ruboBox1.Location = New System.Drawing.Point(32, 32)
       Me.ruboBox1.Name = "ComboBox1"
       Me.ruboBox1.Size = New System.Drawing.Size(136, 21)
       Me.ruboBox1.TabIndex = 0
       Me.ruboBox1.Text = "A"
       "
       "Button1
       "
       Me.Button1.Location = New System.Drawing.Point(128, 112)
       Me.Button1.Name = "Button1"
       Me.Button1.TabIndex = 1
       Me.Button1.Text = "Done"
       "
       "Form1
       "
       Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
       Me.ClientSize = New System.Drawing.Size(328, 173)
       Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Button1, Me.ruboBox1})
       Me.Name = "Form1"
       Me.Text = "ComboBoxDemo"
       Me.ResumeLayout(False)
   End Sub

1. End Region

   Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
       If (ComboBox1.SelectedItem <> "") Then
           MessageBox.Show("You selected: " & ComboBox1.SelectedItem)
       Else
           MessageBox.Show("You must select an item")
       End If
   End Sub

End Class

      </source>

Using ComboBox to select shape to draw

<source lang="vbnet"> Imports System Imports System.Drawing Imports System.Windows.Forms Public Class MainClass

  Shared Sub Main()
       Dim myform As Form = New FrmComboBox()
       Application.Run(myform)
  End Sub " Main

End Class Public Class FrmComboBox

  Inherits Form

1. Region " Windows Form Designer generated code "

  Public Sub New()
     MyBase.New()
     "This call is required by the Windows Form Designer.
     InitializeComponent()
     "Add any initialization after the InitializeComponent() call
  End Sub
  "Form overrides dispose to clean up the component list.
  Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
     If disposing Then
        If Not (components Is Nothing) Then
           components.Dispose()
        End If
     End If
     MyBase.Dispose(disposing)
  End Sub
  Friend WithEvents cboImage As System.Windows.Forms.ruboBox
  "Required by the Windows Form Designer
  Private components As System.ruponentModel.Container
  "NOTE: The following procedure is required by the Windows Form Designer
  "It can be modified using the Windows Form Designer.  
  "Do not modify it using the code editor.
  <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
     Me.cboImage = New System.Windows.Forms.ruboBox()
     Me.SuspendLayout()
     "
     "cboImage
     "
     Me.cboImage.DropDownWidth = 121
     Me.cboImage.Items.AddRange(New Object() {"Circle", "Square", "Ellipse", "Pie", "Filled Circle", "Filled Square", "Filled Ellipse", "Filled Pie"})
     Me.cboImage.Location = New System.Drawing.Point(24, 16)
     Me.cboImage.Name = "cboImage"
     Me.cboImage.Size = New System.Drawing.Size(121, 21)
     Me.cboImage.TabIndex = 0
     "
     "FrmComboBox
     "
     Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
     Me.ClientSize = New System.Drawing.Size(292, 273)
     Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.cboImage})
     Me.Name = "FrmComboBox"
     Me.Text = "ComboBoxTest"
     Me.ResumeLayout(False)
  End Sub

1. End Region

  Private Sub cboImage_SelectedIndexChanged _
     (ByVal sender As System.Object, _
     ByVal e As System.EventArgs) _
     Handles cboImage.SelectedIndexChanged
     Dim myGraphics As Graphics = MyBase.CreateGraphics()
     Dim myPen As New Pen(Color.Red)
     Dim mySolidBrush As New SolidBrush(Color.Red)
     Dim x As Integer
     Dim y As Integer
     Dim width As Integer
     Dim height As Integer
     
     x = 50
     y = 50
     width = 150
     height = 150
     myGraphics.Clear(Color.Black)
     Select Case cboImage.SelectedIndex
        Case 0 
           myGraphics.DrawEllipse(myPen, x, y, width, height)
        Case 1 
           myGraphics.DrawRectangle(myPen, x, y, width, height)
        Case 2 
           myGraphics.DrawEllipse(myPen, x, y, width, 75)
        Case 3 
           myGraphics.DrawPie(myPen, x, y, width, height, 0, 45)
        Case 4 
           myGraphics.FillEllipse(mySolidBrush, x, y, width, height)
        Case 5 
           myGraphics.FillRectangle(mySolidBrush, x, y, width, height)
        Case 6 
           myGraphics.FillEllipse(mySolidBrush, 50, 85, 150, 115)
        Case 7 
           myGraphics.FillPie(mySolidBrush, 50, 50, 150, 150, 0, 45)
     End Select
  End Sub

End Class

      </source>