WPF binding of string property and Button.Content

The quotes around Text in the call to the PropertyChangedEventArgs constructor are missing:

Text = "Begin";if (PropertyChanged != null)    PropertyChanged(this, new PropertyChangedEventArgs("Text"));

PropertyChanged wants to see the name of the property that has changed and not the value. Change the event invocation to:

PropertyChanged(this, new PropertyChangedEventArgs("Text")); 

and it will do the job.However I also would change the construction to

public string Text {      get{return _Text;}      protected set {           _Text = value;           if(null != PropertyChanged){                 PropertyChanged(this,new PropertyChangedEventArgs("Text"));          }        } } 

and then dont call the PropertyChanged-event from Start and End.

And to go even a step further, create invocation-methods like:

protected virtual void OnPropertyChanged(string propertyName) {    OnPropertyChanged(new PropertyChangedEventArgs(propertyName));}protected virtual void OnPropertyChanged(PropertyChangedEventArgs e) {    if (null != PropertyChanged) {        PropertyChanged(this,e);    }}

and then call them from your property-setter.

First of all, I used objectdataproviding, but it is not the object "ttt", they are two different things.

Second, PropertyChanged(this,new PropertyChangedEventArgs("Text")); "Text" is the name not the variable.

So, the code is following, may be helpful to others.

The data class:

namespace test3{    public class Test : INotifyPropertyChanged    {         string   _Text = "Begin";        public string Text        {            get{return _Text;}            protected set { _Text = value;            NotifyPropertyChanged("Text");            }        }        public void Start()        {            Text = "Begin";        }        public void End()        {            Text = "End";        }        public event PropertyChangedEventHandler PropertyChanged;        public void NotifyPropertyChanged(string propertyName)        {            if (PropertyChanged != null)            {                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));            }        }     }}

The logical cs:

  public partial class MainWindow : Window    {        public MainWindow()        {            InitializeComponent();            button1.DataContext=ttt;        }         Test ttt = new Test();        private void button1_Click(object sender, RoutedEventArgs e)        {            if (ttt.Text == "Begin")                ttt.End();            else                ttt.Start();        }    }}

The xaml:

<Window x:Class="test3.MainWindow"        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"        xmlns:local="clr-namespace:test3"        Title="MainWindow" Height="350" Width="525" >    <Grid>        <Button Content="{Binding Path=Text,UpdateSourceTrigger=PropertyChanged}" Height="23" HorizontalAlignment="Left" Margin="121,69,0,0" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click" />    </Grid></Window>