WPF Enums in XAML And Root Addressing For Images


By Robbe Morris
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This small code sample demonstrates how to use Enum values in your XAML files. It also includes how to set the image source property in your xaml files to image resources in different assemblies such as the BusinessLogic assembly in this sample.



If your application plans on storing XAML externally from your app and offer extreme styling flexibility to your users, then being able to set icons for various controls is likely to be a requirement for you.  So, just for kicks, I figured I show this quick tip demonstrating how to work with enums in your XAML.


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<Window x:Class="WPFTutorial.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:enums="clr-namespace:BusinessLogic.Enums;assembly=BusinessLogic"
    xmlns:data="clr-namespace:BusinessLogic;assembly=BusinessLogic"
    Title="Window1" Height="518" Width="658" WindowStartupLocation="CenterScreen">
    
    <Window.Resources>
        
          <DataTemplate x:Key="ColumnHeader">
                              
                 <StackPanel Orientation="Horizontal">
                    <TextBlock Text="Candidate"  Margin="3,3,3,3"/>
                </StackPanel>
                  
        </DataTemplate>
       
        <DataTemplate x:Key="Cell"  DataType="x:Type data:Candidate">
                              
        <StackPanel Orientation="Horizontal">
           <Image  x:Name="Icon" HorizontalAlignment="Right"  Margin="3,3,3,3"
VerticalAlignment="Bottom" Width="16" Height="16" Source="/BusinessLogic;component/graphics/icons/Republican.gif"
Stretch="Fill" Visibility="Collapsed"/> <TextBlock Text="{Binding Path=CandidateName, Mode=OneWay}"
Margin="3,3,3,3"/> </StackPanel> <DataTemplate.Triggers> <DataTrigger Binding="{Binding Path=PoliticalPartyType}"> <DataTrigger.Value> <enums:PoliticalPartyTypes> Unknown </enums:PoliticalPartyTypes> </DataTrigger.Value> <Setter TargetName="Icon" Property="Visibility" Value="Hidden"/> </DataTrigger> <DataTrigger Binding="{Binding Path=PoliticalPartyType}"> <DataTrigger.Value> <enums:PoliticalPartyTypes> Republican </enums:PoliticalPartyTypes> </DataTrigger.Value> <Setter TargetName="Icon" Property="Source"
Value="/BusinessLogic;component/graphics/icons/republican.gif"/> <Setter TargetName="Icon" Property="Visibility" Value="Visible"/> </DataTrigger> <DataTrigger Binding="{Binding Path=PoliticalPartyType}"> <DataTrigger.Value> <enums:PoliticalPartyTypes> Democrat </enums:PoliticalPartyTypes> </DataTrigger.Value> <Setter TargetName="Icon" Property="Source"
Value="/BusinessLogic;component/graphics/icons/democrat.gif"/> <Setter TargetName="Icon" Property="Visibility" Value="Visible"/> </DataTrigger> <DataTrigger Binding="{Binding Path=PoliticalPartyType}"> <DataTrigger.Value> <enums:PoliticalPartyTypes> Conservative </enums:PoliticalPartyTypes> </DataTrigger.Value> <Setter TargetName="Icon" Property="Source"
Value="/BusinessLogic;component/graphics/icons/republican.gif"/> <Setter TargetName="Icon" Property="Visibility" Value="Visible"/> </DataTrigger> </DataTemplate.Triggers> </DataTemplate> </Window.Resources> <ListView Name="ListTemplates" Width="Auto" Height="Auto"
VerticalAlignment="Stretch" HorizontalAlignment="Stretch"> <ListView.View> <GridView> <GridViewColumn Header="Candidate Name"
HeaderTemplate="{StaticResource ColumnHeader}"
CellTemplate="{DynamicResource Cell}" /> </GridView> </ListView.View> <ListView.ItemContainerStyle> <Style TargetType="{x:Type ListViewItem}"> <Setter Property="HorizontalContentAlignment"
Value="Stretch" /> </Style> </ListView.ItemContainerStyle> </ListView> </Window> // Code behind using System; using System.Collections.Generic; using System.Collections.ObjectModel; using System.Threading; using System.Windows.Threading; using System.Linq; using System.Text; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Windows.Navigation; using System.Windows.Shapes; using System.ComponentModel; using BusinessLogic; using BusinessLogic.Enums; namespace WPFTutorial { /// <summary> /// Interaction logic for Window1.xaml /// </summary> public partial class Window1 : Window, INotifyPropertyChanged { public Window1() { InitializeComponent(); this.Loaded += new RoutedEventHandler(Window1_Loaded); } private void Window1_Loaded(object sender, RoutedEventArgs e) { LoadCandidates(); this.ListTemplates.ItemsSource = CandidateList; } private void LoadCandidates() { ObservableCollection<Candidate> list = new ObservableCollection<Candidate>(); list.Add(new Candidate(0, "2008", "Candidates", (int)PoliticalPartyTypes.Republican)); list.Add(new Candidate(1, "John", "McCain", (int)PoliticalPartyTypes.Republican)); list.Add(new Candidate(2, "Lord", "Obama", (int)PoliticalPartyTypes.Democrat)); list.Add(new Candidate(3, "Robbe", "Morris", (int)PoliticalPartyTypes.Conservative)); this.CandidateList = list; } private ObservableCollection<Candidate> _candidateList = null; public ObservableCollection<Candidate> CandidateList { get { return _candidateList; } set { _candidateList = value; OnPropertyChanged("CandidateList"); } } private Candidate _selectedCandidate; public Candidate SelectedCandidate { get { return _selectedCandidate; } set { _selectedCandidate = value; OnPropertyChanged("SelectedCandidate"); } } public event PropertyChangedEventHandler PropertyChanged; protected void OnPropertyChanged(string propertyName) { if (PropertyChanged == null) { return; } PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } } using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace BusinessLogic { public class Candidate { public Candidate(int candidateID, string firstName, string lastName, int politicalPartyID) { _candidateID = candidateID; _firstName = firstName; _lastName = lastName; _politicalPartyTypeID = politicalPartyID; } private int _candidateID = 0; public int CandidateID { get { return _candidateID; } set { _candidateID = value; } } public string CandidateName { get { return FirstName + " " + LastName; } } private string _firstName = string.Empty; public string FirstName { get { return _firstName; } set { _firstName = value.Trim(); } } private string _lastName = string.Empty; public string LastName { get { return _lastName; } set { _lastName = value.Trim(); } } private int _politicalPartyTypeID = 0; public int PoliticalPartyTypeID { get { return _politicalPartyTypeID; } set { _politicalPartyTypeID = value; } } public Enums.PoliticalPartyTypes PoliticalPartyType { get { return (Enums.PoliticalPartyTypes)_politicalPartyTypeID; } } } } using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace BusinessLogic.Enums { public enum PoliticalPartyTypes : int { Unknown = 0, Republican = 1, Democrat = 2, Conservative = 3 } }


Biography
Robbe is a 2004-2008 Microsoft MVP for C# and the .NET Evangelist for Alinean Inc..  He is also the co-founder of EggHeadCafe. Robbe enjoys scuba diving with the folks at wet-n-fla.


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Article Discussion: WPF - Silverlight Enums in XAML And Root Addressing For Images
Robbe Morris posted at 04-Sep-08 08:02
Original Article