I tried to bind a UserControl in two-way mode, but there isn't any notification when the custom control is updated.
I used the following post to fix it up without success WPF usercontrol Twoway binding Dependency Property
When I update the main window control, the UserControl receives the data and displays the correct values. But when I update the UserControl, nothing changes in the main window.
MainWindow C#:
using System.Collections.Generic;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Windows;
namespace WpfAppUserControl_Test1
{
public partial class MainWindow : Window
{
TextBinding textBinding = new TextBinding();
private class TextBinding : INotifyPropertyChanged
{
private string TextCtrlValue = "";
public string TextCtrl
{
get { return TextCtrlValue; }
set { TextCtrlValue = value; NotifyPropertyChanged("TextCtrl"); }
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
private List<int> ComboListValue = new List<int>();
public List<int> ComboList
{
get { return ComboListValue; }
set { ComboListValue = value; NotifyPropertyChanged("ComboList"); }
}
public int ComboSelectedValue = 1;
public int ComboSelected
{
get { return ComboSelectedValue; }
set { ComboSelectedValue = value; NotifyPropertyChanged("ComboSelected"); }
}
}
public MainWindow()
{
InitializeComponent();
DataContext = textBinding;
textBinding.ComboList.Add(1);
textBinding.ComboList.Add(2);
textBinding.ComboList.Add(3);
textBinding.ComboList.Add(4);
textBinding.ComboSelected = 1;
textBinding.TextCtrl = "Foo";
}
}
}
MainWindow XAML :
<Window x:Class="WpfAppUserControl_Test1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfAppUserControl_Test1"
mc:Ignorable="d"
DataContext="{Binding RelativeSource={RelativeSource Self}}"
Title="MainWindow" Height="181" Width="367">
<Grid>
<local:UserControlTest1
TextValue="{Binding Path=TextCtrl, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
ComboValues="{Binding Path=ComboList}"
ComboSelected ="{Binding Path=ComboSelected, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top"/>
<Rectangle HorizontalAlignment="Left" Height="116" Margin="189,10,0,0" Stroke="LightGray" VerticalAlignment="Top" Fill="LightGray" Width="146"/>
<Label Content="Main Window" HorizontalAlignment="Left" Height="23" Margin="205,20,0,0" VerticalAlignment="Top" HorizontalContentAlignment="Center" Width="114"/>
<TextBox
Text="{Binding Path=TextCtrl, UpdateSourceTrigger=PropertyChanged}"
HorizontalAlignment="Left" VerticalAlignment="Top" Width="114" Height="23" Margin="205,57,0,0" TextWrapping="Wrap"/>
<ComboBox
ItemsSource="{Binding Path=ComboList}"
SelectedValue="{Binding Path=ComboSelected, UpdateSourceTrigger=PropertyChanged}"
DisplayMemberPath="" SelectedValuePath=""
HorizontalAlignment="Left" Margin="202,96,0,0" VerticalAlignment="Top" Width="120"/>
</Grid>
</Window>
UserControl XAML :
<UserControl x:Class="WpfAppUserControl_Test1.UserControlTest1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:WpfAppUserControl_Test1"
mc:Ignorable="d"
Height="116" Width="139" Background="DarkGray">
<Grid>
<Label
Content="User Control" HorizontalAlignment="Center" Height="28" Margin="0,10,0,0" VerticalAlignment="Top" HorizontalContentAlignment="Center" Width="119"/>
<TextBox
Text="{Binding RelativeSource={RelativeSource AncestorType={x:Type local:UserControlTest1}}, Path=TextValue}"
Margin="0,47,0,0" TextWrapping="Wrap"
HorizontalAlignment="Center" VerticalAlignment="Top" Width="119" Height="20"/>
<ComboBox
ItemsSource="{Binding RelativeSource={RelativeSource AncestorType={x:Type local:UserControlTest1}}, Path=ComboValues}"
SelectedValue="{Binding RelativeSource={RelativeSource AncestorType={x:Type local:UserControlTest1}}, Path=ComboSelected}"
DisplayMemberPath="" SelectedValuePath=""
HorizontalAlignment="Center" VerticalAlignment="Top" Margin="0,84,0,0" Width="118"/>
</Grid>
</UserControl>
UserControl C# :
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
namespace WpfAppUserControl_Test1
{
public partial class UserControlTest1 : UserControl
{
public static readonly DependencyProperty TextValueProperty = DependencyProperty.Register("TextValue",
typeof(string),
typeof(UserControlTest1),
//new PropertyMetadata(null));
new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault));
public string TextValue
{
get => (string)GetValue(TextValueProperty);
set => SetValue(TextValueProperty, value);
}
public static readonly DependencyProperty ComboValuesProperty = DependencyProperty.Register("ComboValues",
typeof(List<int>),
typeof(UserControlTest1),
new PropertyMetadata(null));
public string ComboValues
{
get => (string)GetValue(ComboValuesProperty);
set => SetValue(ComboValuesProperty, value);
}
public static readonly DependencyProperty ComboSelectedProperty = DependencyProperty.Register("ComboSelected",
typeof(int),
typeof(UserControlTest1),
//new PropertyMetadata(null));
new FrameworkPropertyMetadata(0, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault));
public int ComboSelected
{
get => (int)GetValue(ComboSelectedProperty);
set => SetValue(ComboSelectedProperty, value);
}
public UserControlTest1()
{
InitializeComponent();
}
}
}
