System windows data error 40 bindingexpression path error

I’m banging my head on my desk with this binding error.. I have checked several of the postings for the BindingExpression path error and cannot see anything that works with my situation.

Anyway, I have a custom control called IncrementingTextBox. I am trying to disable it whenever the user ‘checks’ the CheckBox above it.

I have a binding on the CheckBox IsChecked property that is working fine and is firing when it is supposed to. It is correctly setting the UseSensorLength property on the ConfigurationModel.

However, the binding on the IncrementingTextBox IsEnabled property is causing a BindingExpression path error and so doesn’t update at all.

As a test, I tried in the code behind to enable and disable the control and it works just fine, but I can’t seem to get the Binding to work on it.

Here is a snippet from my xaml:

...

DataContext="{Binding RelativeSource={RelativeSource Self}}"

...
...

<CheckBox Content="Use Sensor Length" Margin="30,6,0,0" 
          IsChecked="{Binding ConfigurationModel.UseSensorLength, Mode=TwoWay}"/>

<local:IncrementingTextBox x:Name="video_length_textbox" Margin="0,0,0,5" 
                           IsTextEnabled="False" 
                           IsEnabled="{Binding ConfigurationModel.DontUseSensorLength}" 
                           ValueChanged="VideoEventValueChanged"/>

And Here is a snippet from my ConfigurationModel:

public bool DontUseSensorLength
{
    get { return !UseSensorLength; }
}

public bool UseSensorLength
{
   get { return _useSensorLength; }
   set 
   { 
      _useSensorLength = value; 
      OnPropertyChanged("UseSensorLength"); 
      OnPropertyChanged("DontUseSensorLength");
   }
}

Here is the error message I am getting in my output window when running the app:

System.Windows.Data Error: 40 : BindingExpression path error:
‘ConfigurationModel’ property not found on ‘object’
»IncrementingTextBox’ (Name=’video_length_textbox’)’.
BindingExpression:Path=ConfigurationModel.DontUseSensorLength;
DataItem=’IncrementingTextBox’ (Name=’video_length_textbox’); target
element is ‘IncrementingTextBox’ (Name=’video_length_textbox’); target
property is ‘IsEnabled’ (type ‘Boolean’)

Remember, the ‘UseSensorLength’ property binding is working fine, but the ‘DontUseSensorLength’ binding is causing the above ‘BindingExpression path error’.

Greetings;

        public CallStackDialog(Window owner,
               FormattedStackTrace stackTrace)
        {
            InitializeComponent();
            this.Owner = owner;

            StackTrace = stackTrace;
            DataContext = StackTrace;

            return;
        }

        private FormattedStackTrace formattedStackTrace;

        public FormattedStackTrace StackTrace
        {
            get
            {
                return formattedStackTrace;
            }

            set
            {
                formattedStackTrace = value;
                NotifyPropertyChanged("StackTrace");
            }
        }

3.) The FormattedStackTrace class contains an instance of List<OrderedCall> as an auto property named OrderedStackTrace.  I am trying to bind this collection as the ItemsSource for the DataGrid in the window. The relative members of the FormattedStackTrace,
which is the backing reference type for the Window’s DataContext, is as follows:

    public class FormattedStackTrace
    {
#region FormattedStackTrace Class Data Members & Auto-Properties

        private StackFrame[] sourceStackFrame;
        public MethodBase CallingMethod { get; private set; }
        public List<OrderedCall> OrderedStackTrace { get; private set; }

#endregion
    }

OrderedStackTrace is a List<OrderedCall>, where each List member is an instance of the following structure:

    public struct OrderedCall
    {
        public int Call;
        public string Method;
    }; 

At the point where the DataContext is set inside the parent Window’s class constructor, the OrderedStackTrace property is correct, in that it contains the expected number of OrderedCall instance values, and they can be viewed without issue inside any of the
Debugging tabs inside Visual Studio 2010, or inside the IDE’s Immediate Window:

    ? StackTrace.OrderedStackTrace == null
    false
    ? StackTrace.OrderedStackTrace.Count
    40
    ? StackTrace.OrderedStackTrace[39]
    {WPFEventHandling.OrderedCall}
        Call: 40
        Method: «WPFEventHandling.MainWindow.OnMousePointerEnteredButton(Object sender, MouseEventArgs e)»

4.) The DataGrid inside the Window I’m trying to bind to, StackTraceDataGrid, which is read only, is implemented in XAML as follows:

<DataGrid Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2" 
          Name="StackTraceDataGrid" IsReadOnly="True"
          AutoGenerateColumns="False" Margin="10" 
          ItemsSource="StackTrace.OrderedStackTrace">
    <DataGrid.Columns>
        <DataGridTextColumn Header="Offest" 
         Binding="{Binding Call}" Width="60">
        </DataGridTextColumn>
        <DataGridTextColumn Header="Method" 
         Binding="{Binding Method}" Width="*">
        </DataGridTextColumn>
    </DataGrid.Columns>
</DataGrid>

When I build the solution containing this Window and  the child StackTraceDataGrid control, there are no errors nor compiler warnings. When I bring up the parent window that contains StakTraceDataGrid, the DataGrid and the two Text Columns, Offset and
Method, are rendered and formatted as expected, but each row in the DataGrid is empty.  When the Window is brought up, the following set of runtime messages appear for each pair of OrderedCall member values in each column for each row:

System.Windows.Data Error: 40 : BindingExpression path error: ‘Call’ property not found on ‘object’ »Char’ (HashCode=7471218)’. BindingExpression:Path=Call; DataItem=’Char’ (HashCode=7471218); target element is ‘TextBlock’ (Name=»); target property is ‘Text’
(type ‘String’)
System.Windows.Data Error: 40 : BindingExpression path error: ‘Method’ property not found on ‘object’ »Char’ (HashCode=7471218)’. BindingExpression:Path=Method; DataItem=’Char’ (HashCode=7471218); target element is ‘TextBlock’ (Name=»); target property is
‘Text’ (type ‘String’)

As far as I can tell, I think that my problem may lie in how I’ve defined the ItemsSource property for the DataGrid, and the Binding Path for each column for each instance of OrderedCall as I would like to have displayed in each row of the Grid.

I would really appreciate any corrections on how to resolve the BindingExpression path errors I’m seeing at runtime, as well as any background informatio on what each DataGrid Column is expecting for a Binding Path for each item in each row of the DataGrid.

Thank you in advance for your time and help, and I look forward to hearing from you soon.

Hello,

I have changed the title of my question because I don’t understand this error in the binding with the view.I know how to read it,but i don’t understand it’s cause or how should I change the syntax for it in a proper solution.This is my method for storing values:

View-Model:

public void SaveTeacher(object param)
        {

            using (DatabaseStudentsEntitiesLastStand db = new DatabaseStudentsEntitiesLastStand())
            {
              
                RegisterTeacher t = new RegisterTeacher();

                if (isChecked == true || t.CourseName != null)
                {
                    t.CourseName = courseName;

                }
                t.SNTeacher = SNTeacher;
                t.UserName = _UserName;
                t.pwd = pwd;
                t.fullName = fullName;
                t.education = education;

                db.RegisterTeachers.Attach(t);
               
                try
                {
                    db.SaveChanges();
                }
                catch (Exception ex)
                {
                   
                            MessageBox.Show(ex.Message);
                       
                }
            }
        }

This is the isChecked property:

private bool isChecked;
        public bool IsChecked
        {
            get
            {
                return IsChecked;
            }
            set
            {
                if (isChecked != value)
                {
                    isChecked = value;
                    NotifyOnPropertyChange("IsChecked");
                }
            }
        }
        private DelegateCommand checkCommand;
        public DelegateCommand CheckCommand
        {
            get
            {
                if (checkCommand == null)
                    checkCommand = new DelegateCommand(SaveTeacher, null);
                return checkCommand;
            }
            set
            {
                checkCommand = value;
                NotifyOnPropertyChange("CheckCommand");
            }
        }

This is the binding with the view:

<Button Content="Submit" Command="{Binding SaveCommand}"  HorizontalAlignment="Left" Margin="517,98.4,0,0" Grid.Row="2" VerticalAlignment="Top" Width="110" Height="40"/>
        <Button Content="Cancel"  HorizontalAlignment="Left" Margin="361,98.4,0,0" Grid.Row="2" VerticalAlignment="Top" Width="111" Height="40"/>
        <ListBox  HorizontalAlignment="Left" Name="coursesList" Height="240"   Margin="418,13.2,0,0" Grid.Row="1" VerticalAlignment="Top" Width="225" Grid.RowSpan="2"  ItemsSource="{Binding Courses}" >
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <CheckBox x:Name="CheckBoxCourses" Click="CheckBoxCourses_Click"
                              IsChecked="{Binding Path=IsChecked,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}"
                           Command="{Binding CheckCommand,Mode=TwoWay}"

                            Content="{Binding Path=courseName,Mode=TwoWay}" Margin="0"/>


                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>

This is the Checked event:

private void CheckBoxCourses_Checked(object sender, RoutedEventArgs e)
        {
            var checkbox = sender as CheckBox;
            if(checkbox!=null)
            {
                checkbox.IsChecked =true;
            }


          
        }

What I have tried:

This is the entire error:

System.Windows.Data Error: 40 : BindingExpression path error: 'IsSelected' property not found on 'object' ''Cours' (HashCode=44335814)'. BindingExpression:Path=IsSelected; DataItem='Cours' (HashCode=44335814); target element is 'CheckBox' (Name=''); target property is 'IsChecked' (type 'Nullable`1')

I have tried multiple solutions with delegatecommand,selecteditem in the listbox and IsSelected property,read-only properties,nothing is working.Since I have tried many approaches,I have moved the property IsChecked from the view-model to the model class named «Cours» along with NotifyPropertyChanged(so it basically looks like the one I have in my example,only that it is in the model,not vm).Can someone please tell me what would be the problem based on this error?Please notify me if you need certain lines of code.