MultiBinding WPF Example

WPF > Windows > Data > MultiBinding

Represents a collection of Binding objects attached to a single binding target property.

Example

XAML

<Window x:Class="WpfApplication4.MainWindow"

        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

        Title="MainWindow" Height="350" Width="525"

        xmlns:local="clr-namespace:WpfApplication4">

    <Window.Resources>

        <local:NameConvertor x:Key="nameConvertor"></local:NameConvertor>

    </Window.Resources>

    <Grid>

        <Grid>

            <TextBlock HorizontalAlignment="Left" Margin="20,30,0,0" TextWrapping="Wrap" Text="First Name" VerticalAlignment="Top"/>

            <TextBox x:Name="txtFirstName" HorizontalAlignment="Left" Height="23" Margin="86,27,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120"/>

            <TextBlock HorizontalAlignment="Left" Margin="20,68,0,0" TextWrapping="Wrap" Text="Last Name" VerticalAlignment="Top"/>

            <TextBox x:Name="txtLastName" HorizontalAlignment="Left" Height="23" Margin="86,65,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120"/>

            <TextBlock HorizontalAlignment="Left" Margin="20,110,0,0" TextWrapping="Wrap" Text="Full Name" VerticalAlignment="Top"/>

            <TextBox x:Name="txtLastName_Copy" HorizontalAlignment="Left" Height="23" Margin="86,107,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="267">

                <TextBox.Text>

                    <MultiBinding Converter="{StaticResource nameConvertor}" UpdateSourceTrigger="PropertyChanged">

                        <Binding ElementName="txtFirstName" Path="Text" />

                        <Binding ElementName="txtLastName" Path="Text" />

                    </MultiBinding>

                </TextBox.Text>

            </TextBox>

        </Grid>

    </Grid>

</Window>

C#

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

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;

namespace WpfApplication4

{

    public class NameConvertor : IMultiValueConverter

    {

        public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)

        {

            return String.Concat(values[0], ",", values[1]);

        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)

        {

            return (value as string).Split(',');

        }

    }

    /// <summary>

    /// Interaction logic for MainWindow.xaml

    /// </summary>

    public partial class MainWindow : Window

    {

        public MainWindow()

        {

            InitializeComponent();

        }

    }

}

Data Namespace WPF

WPF > Windows > Data Namespace

Contains classes used for binding properties to data sources

• MultiBinding

ComboBoxItem WPF Example

WPF > Controls  > ContentControl > ComboBoxItem 

ComboBoxItem represent an item in a ComboBox.


Example:

XAML

<Window x:Class="WpfApplication3.MainWindow"

        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

        Title="MainWindow" Height="350" Width="525">

    <Grid>

        <ComboBox x:Name="cbo" HorizontalAlignment="Left" VerticalAlignment="Top" Width="120" SelectionChanged="ComboBox_SelectionChanged">

            <ComboBoxItem>Option1</ComboBoxItem>

            <ComboBoxItem>Option2</ComboBoxItem>

        </ComboBox>

    </Grid>

</Window>

C#

private void ComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e)

{

  string value = ((ComboBoxItem)cbo.SelectedItem).Content.ToString();

}

WPF Read RSS feed and bind to DataGrid

WPF > SyndicationFeed > Read RSS feed

Read RSS feed and bind to DataGrid

XAML

<Window x:Class="Feed.MainWindow"

        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

        Title="Rss Feed" Height="670" Width="737" Loaded="Window_Loaded">

    <Grid>

        <DataGrid ItemsSource="{Binding RssFeedList}"  AutoGenerateColumns="False" IsReadOnly="True">

            <DataGrid.Columns>

                <DataGridTextColumn Header="Title" Binding="{Binding Title}"/>

            </DataGrid.Columns>

        </DataGrid>

      

    </Grid>

</Window>

c#

using System;

using System.Collections.Generic;

using System.Collections.ObjectModel;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

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;

namespace Feed

{

    public class RssFeed

    {

        public string Title { get; set; }

    }

      

      

    /// <summary>

    /// Interaction logic for MainWindow.xaml

    /// </summary>

    public partial class MainWindow : Window

    {

        public ObservableCollection<RssFeed> RssFeedList { get; set; }

        public MainWindow()

        {

            InitializeComponent();

        }

        private void Window_Loaded(object sender, RoutedEventArgs e)

        {

            string feedUrl = "http://rss.cnn.com/rss/cnn_latest.rss";

            System.Xml.XmlReader reader = System.Xml.XmlReader.Create(feedUrl);

            System.ServiceModel.Syndication.SyndicationFeed feed = System.ServiceModel.Syndication.SyndicationFeed.Load(reader);

            RssFeedList = new ObservableCollection<RssFeed>();

            foreach (var item in feed.Items)

            {

                RssFeed rf = new RssFeed();

                rf.Title = item.Title.Text.ToString();

                RssFeedList.Add(rf);

            }

            this.DataContext = this;

        }

    }

}

Get tree visual elements WPF

WPF > Windows > Media > VisualTreeHelper 

VisualTreeHelper provides methods that perform

tasks involving nodes in a visual tree.

Example:

Get tree visual elements for user control

FrameworkElement fe = (FrameworkElement)YourControl;

for (int i = 0; i < VisualTreeHelper.GetChildrenCount(fe); i++)

{

   Grid childVisual = (Grid)VisualTreeHelper.GetChild(fe, i);

   childVisual.Width = sp.ActualWidth;

}

WPF Converter Example

WPF > Data > Converters

Converters changes data from one type to another and apply custom logic to binding.

Implementation : create a class that implements the IvalueConverter.

Example:

XAML:

<Window x:Class="WpfApplication2.MainWindow"

        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

        xmlns:local="clr-namespace:WpfApplication2"

        Title="MainWindow" Height="350" Width="525">

    <Window.Resources>

        <local:YesNoConverter x:Key="YesNoConverter" />

    </Window.Resources>

    <StackPanel Margin="5">

        <CheckBox x:Name="chk" IsChecked="{Binding ElementName=txtYesNo, Path=Text, Converter={StaticResource YesNoConverter}}" Content="Yes/No" />

        <TextBox Name="txtYesNo" />

    </StackPanel>

</Window>

C# Code:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

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;

namespace WpfApplication2

{

    /// <summary>

    /// Interaction logic for MainWindow.xaml

    /// </summary>

    ///

    public class YesNoConverter : IValueConverter

    {

        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)

        {

            switch (value.ToString())

            {

                case "Yes":

                    return true;

                case "No":

                    return false;

            }

            return false;

        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)

        {

            if (value is bool)

            {

                if ((bool)value == true)

                    return "Yes";

                else

                    return "No";

            }

            return "No";

        }

    }

    public partial class MainWindow : Window

    {

     

        public MainWindow()

        {

            InitializeComponent();

        }

    }

}