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.

Solution

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>