Use the FontSizeConverter class to convert the content of a ListBoxItem to a value that represents the size of a font. : ListBox « Windows Presentation Foundation « VB.Net Tutorial

1. VB.Net Tutorial
2. Windows Presentation Foundation
3. ListBox

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    x:Class="FontSizeConverter_Csharp.Window1"
    Title="FontSizeConverter Sample">
<StackPanel>
        <TextBlock Name="text1" TextWrapping="Wrap" Height="300" Width="500">
            this is a test
        </TextBlock>
    <ListBox Grid.Column="1" Grid.Row="1" VerticalAlignment="Top" Height="50" Margin="10,0,0,0" SelectionChanged="changeSize">
        <ListBoxItem>5</ListBoxItem>
        <ListBoxItem>8</ListBoxItem>
        <ListBoxItem>11</ListBoxItem>
        <ListBoxItem>14</ListBoxItem>
        <ListBoxItem>17</ListBoxItem>
        <ListBoxItem>20</ListBoxItem>
        <ListBoxItem>23</ListBoxItem>
        <ListBoxItem>26</ListBoxItem>
        <ListBoxItem>29</ListBoxItem>
        <ListBoxItem>32</ListBoxItem>
    </ListBox>
    <ListBox Grid.Column="3" Grid.Row="1" VerticalAlignment="Top" Height="50" Margin="10,0,0,0" SelectionChanged="changeFamily">
      <ListBoxItem>Arial</ListBoxItem>
      <ListBoxItem>Courier New</ListBoxItem>
      <ListBoxItem>Tahoma</ListBoxItem>
      <ListBoxItem>Times New Roman</ListBoxItem>
      <ListBoxItem>Verdana</ListBoxItem>
    </ListBox>      
   
  </StackPanel>        
</Window>
//File:Window.xaml.vb


Imports System
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Documents
Imports System.Windows.Navigation
Imports System.Windows.Media

Namespace FontSizeConverter_Csharp
  Public Partial Class Window1
    Inherits Window
    Public Sub changeSize(sender As Object, args As SelectionChangedEventArgs)
      Dim li As ListBoxItem = TryCast(TryCast(sender, ListBox).SelectedItem, ListBoxItem)
      Dim myFontSizeConverter As New FontSizeConverter()
      text1.FontSize = CType(myFontSizeConverter.ConvertFromString(li.Content.ToString()), [Double])
    End Sub

    Public Sub changeFamily(sender As Object, args As SelectionChangedEventArgs)
      Dim li2 As ListBoxItem = TryCast(TryCast(sender, ListBox).SelectedItem, ListBoxItem)
      text1.FontFamily = New System.Windows.Media.FontFamily(li2.Content.ToString())
    End Sub
  End Class
End Namespace

16.27.ListBox
	16.27.1.	Bind String Array Resource to ListBox
	16.27.2.	Use Data Templates to Display Bound Data
	16.27.3.	CheckBox List
	16.27.4.	Convert the contents of a ListBoxItem to an instance of GridLength by using GridLengthConverter
	16.27.5.	Use the FontSizeConverter class to convert the content of a ListBoxItem to a value that represents the size of a font.
	16.27.6.	Convert contents of a ListBoxItem to an instance of Thickness by using the ThicknessConverter
	16.27.7.	DataTrigger, ListBox and user object
	16.27.8.	Add selected file to ListBox
	16.27.9.	This list box allows items to be selected in groups by using the SHIFT key and mouse or the CTRL key and space key.
	16.27.10.	Iterate through the selected items and remove each one
	16.27.11.	Ensure there is at least one item selected