Update textbox wpf C# on string Update

Question

I have the follow situation:

One textbox that updates when string value changes, like a log field.

my implementation:

XAML

...

       <TextBox x:Name="txtLogView" Margin="10" Grid.Row="1" TextWrapping="Wrap">
            <TextBox.Text>
                <Binding Path="TextoLog"  Mode="TwoWay" UpdateSourceTrigger="PropertyChanged"/>
            </TextBox.Text>
        </TextBox> 

...

SerialManager.cs

...
private StringBuilder logText;
...

public String TextoLog
    {
        get { return logText.ToString(); }
        set { logText.Append(value); OnPropertyChanged("TextoLog"); }

    }

...

  private void DataReceivedHandler(object sender, SerialDataReceivedEventArgs e)
    {

        SerialPort sp = (SerialPort)sender;
        string indata = sp.ReadExisting();
        TextoLog = indata;

     }

The variable logText is updated when a new data arrives on serial port, i saw that in "set" property of Textlog, put the "get" property never is called and the textbox never shows the text.

Answer 1

The error was resolved setting the Datacontext of textbox on mainwindow initialization, as follow:

  private void InitDataModels()
        {
            SerialManager = new SerialManager();
            cbPorts.DataContext = SerialManager;
            txtLogView.DataContext = SerialManager;

            this.DataContext = this;
        }