Binding to an Static property of an Static class doesn't work

Question

I'm trying to Bind the Text property of the TextBlock to StaticClass.Percent. Since I couldn't do that (Or could I?) I have defined the LoadingPercent in my ViewModel so that I can bind to it. It is still not working. How can I solve this? Or can I bind to the StaticClass directly and ignore the ViewModel approach?

<Window x:Class="TestBinding.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:testBinding="clr-namespace:TestBinding"
        Title="MainWindow" Height="350" Width="525">
    <Window.DataContext>
        <testBinding:ViewModel/>
    </Window.DataContext>
    <StackPanel>
        <TextBlock Width="100" 
                   HorizontalAlignment="Center"
                   Text="{Binding LoadingPercent}"/>
        <Button Content="Change" 
                Width="200" 
                Height="30" 
                Margin="0 20 0 0" 
                HorizontalAlignment="Center"
                Click="ChangeText"/>
    </StackPanel>
</Window>

public partial class MainWindow
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void ChangeText(object sender, RoutedEventArgs e)
    {
        StaticClass.Percentage = 10;
    }
}

public class ViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    private double loadingPercent;
    public double LoadingPercent
    {
        get { return StaticClass.Percentage; }
        set
        {
            loadingPercent = value;
            RaisePropertyChanged("LoadingPercent");
        }
    }

    private void RaisePropertyChanged(string propertyName)
    {
        var handler = PropertyChanged;
        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

public static class StaticClass
{
    public static int Percentage { get; set; }
}

score 2 · Answer 1 · edited May 23 '17 at 10:26

2

Here is a mistake:

private double loadingPercent;
public double LoadingPercent
{
    get { return StaticClass.Percentage; }
    set
    {
        loadingPercent = value;
        RaisePropertyChanged("LoadingPercent");
    }
}

You return in get the StaticClass.Percentage but you assign loadingPercent in set.

I am not sure why you need the static class after all, but if you want to ditch the viewmodel and bind directly to the static property, see here

edited May 23 '17 at 10:26

Community

1
1

answered Aug 19 '14 at 23:02

thumbmunkeys

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I'm doing some calculations in the static class which I need to show in the TextBlock in real-time. I've tried the accepted answer in the link you just gave, but I couldn't get it working. – Vahid Aug 19 '14 at 23:07
If you modify the static class property, then there is no way for the view to get the modification. You have to use `INotifyPropertyChanged` – thumbmunkeys Aug 19 '14 at 23:33
But I can't use `INotifyPropertyChanged` in an static class. – Vahid Aug 19 '14 at 23:43

Binding to an Static property of an Static class doesn't work

1 Answers1