wpf textbox text binding

Question

i am trying to bind the text of a textbox to a property in my class, and it is not working, I am editing the property in the code behind but I don't see the string in the textbox this is the class, and the property i am trying to bind is called songFolder.

public class song :  INotifyPropertyChanged
{
    public string title {get; set; }
    public string artist { get; set; }
    public string path { get; set; }
    public static string folder;
    public string songsFolder { get { return folder; } set { folder = value; NotifyPropertyChanged("songsFolder"); } }

    public event PropertyChangedEventHandler PropertyChanged;

    private void NotifyPropertyChanged(String propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    public song()
    {

    }

    public song(string title, string artist, string path)
    {
        this.title = title;
        this.artist = artist;
        this.path = path;
    }

}

and the xaml, containing the resource and the textbox wich i am tring to bind

<Window x:Class="WpfApplication1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:WpfApplication1"
    Title="Song Filler" Height="455" Width="525">
<Window.Resources>
    <local:song x:Key="song"/>
</Window.Resources>
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="auto"/>
        </Grid.ColumnDefinitions>
        <TextBox Name="browseBox" Text="{Binding Source={StaticResource ResourceKey=song}, Path=songsFolder, Mode=TwoWay}" Grid.Column="0"></TextBox>
        <Button Grid.Column="1" Width="auto" Click="Browse">browse</Button>
    </Grid>

--------------update---------------- I added the next line to ctor of the window:

BrowseBox.DataContext=new song()

And while debugging I saw that the property is changing but the text in the textbox isn't.

Answer 1

The string passed into the NotifyPropertyChanged event should be the same name of the property itself.

public string songsFolder 
{ 
    get 
    { 
      return folder; 
    } 
    set 
    { 
      folder = value; 
      NotifyPropertyChanged("songsFolder"); 
    }
}

Also,

try adding UpdateSourceTrigger="PropertyChanged" to the binding of the textBox

<TextBox Name="browseBox" Text="{Binding Source={StaticResource ResourceKey=song}, Path=songsFolder, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Grid.Column="0"></TextBox>

Edit: Maybe the DataContext is not getting set correctly. You can also try this method (W/out a static Key)

Code behind, inside the Ctor of the window:

browseBox.DataContext = new song();

Then, update textBox finding to:

<TextBox Name="browseBox" Text="{Binding Path=songsFolder, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Grid.Column="0"></TextBox>