I have a simple WPF window with a slider and two textblocks. As the slider moves it updates a data bound object. Now the first textblock updates while the second does not. Why?
You may say there is no INotifyPropertyChanged here. But then why is the first updating? I have pulled my hair enough. Please help.
My WPF app in all its glory is as follows.
<Window x:Class="DataTriggerDemo.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:DataTriggerDemo"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<Slider x:Name="MySlider" Margin="5" Minimum="0" Maximum="100"
Value="{Binding TheValue}"/>
<TextBlock Grid.Row="1" Text="{Binding TheValue}" />
<TextBlock Grid.Row="2" Text="{Binding TheValueTwice}" />
</Grid>
</Window>
And now the code behind.
using System.Windows;
namespace DataTriggerDemo
{
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
DataContext = new DataObject();
}
}
public class DataObject
{
private int _theValue;
public int TheValue
{
get { return _theValue; }
set {
_theValue = value;
TheValueTwice = _theValue * 2;
}
}
private int _theValueTwice;
public int TheValueTwice
{
get {
return _theValueTwice;
}
set {
_theValueTwice = value;
}
}
}
}
