An unhandled exception of type "System.Windows.Markup.XamlParseException" occurred in PresentationFramework.dll

Question

I am working on a small application in C # / WPF that feeds data from a serial port. It also reads a text file containing some constants in order to calculate something. An event handler handles incoming data when it arrives:

_serialPort.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(Receive); 

Here is the receipt handler along with the delegate that is created in the dispatcher to further update the user interface.

 private delegate void UpdateUiTextDelegate(string text); private void Receive(object sender, System.IO.Ports.SerialDataReceivedEventArgs e) { // collect characters received to our 'buffer' (string) try { // stops long running output timer if enabled if (dispatcherTimer.IsEnabled) { dispatcherTimer.Stop(); } message = _serialPort.ReadLine(); dispatcherTimer.Start(); Dispatcher.Invoke(DispatcherPriority.Send, new UpdateUiTextDelegate(updateUI), message); } catch (Exception ex) { // timeout dispatcherTimer.Start(); SerialCmdSend("SCAN"); } } 

dispatcherTimer allows you to resend commands to a device on a serial line if it cannot receive any data in a reasonable amount of time.

In addition to reading from a text file, the application has several gestures for keys defined in the designer of the main window:

 public MainWindow() { InitializeComponent(); InitializeComponent(); KeyGesture kg = new KeyGesture(Key.C, ModifierKeys.Control); InputBinding ib = new InputBinding(MyCommand, kg); this.InputBindings.Add(ib); Start(); } 

So, MainWindow.xaml has this command binding code:

 <Window.CommandBindings> <CommandBinding Command="{x:Static custom:MainWindow.MyCommand}" Executed="MyCommandExecuted" CanExecute="CanExecuteMyCommand" /> </Window.CommandBindings> 

Visual Studio Designer complains about invalid markup, but it is still used to work fine, until I started getting these errors when I started the program:

An unhandled exception of type 'System.Windows.Markup.XamlParseException' occurred in PresentationFramework.dll

Additional information: 'A call to the constructor of the type “Vaernes.MainWindow” that matches the specified binding constraints threw an exception. ”Line number“ 4 ”and line position“ 9 ”.

This error appears after making minor code changes. The latter was a replacement for a text file read by a program with a different one with the same name (Add existing item ...). I searched around some online solutions, but cannot find anything similar to my problem.

I suspect this has something to do with the Dispatcher stream or input bindings. I also tried adding an exception handler and noticed that the sender was System.Windows.Threading.Dispatcher.

Anyone suggestions?

Answer 1

The XamlParseException in most (if not all) cases is excluded from within the constructor.

To solve this problem, you should get InnerException (and maybe InnerException, as well as aso) and callstack. Then fix it.

If the exception does not occur during debugging, you can try / catch the exception inside the constructor and write all the necessary data.