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

I’m working on a small application in C# / WPF that is fed by data from the serial port. It also reads a text file containing some constants in order to calculate something. An event handler is made to handle the incoming data when it arrives:

Here is the Receive handler, along with a delegate that is created in a Dispatcher, to further update the UI.

The dispatcherTimer allows resending commands to the unit on the serial line, if it fails to get any data in a reasonable amount of time.

In addition to also reading from a text file, the application has some keyboard shortcut gestures defined in the constructor of the main window:

So the MainWindow.xaml has this command binding code:

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

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

Additional information: ‘The invocation of the constructor on type ‘Vaernes.MainWindow’ that matches the specified binding constraints threw an exception.’ Line number ‘4’ and line position ‘9’.

This kind of error appears after making small code changes. The latest was replacing the text file read by the program, with another one with the same name (Add Existing item. ). I have searched around some on the web for solutions but I can’t find any that is quite similar to my problem.

System.Windows.Markup.XamlParseException

I have written a WPF application, on my compuyter it is running ok. Now I am trying to deploy wpf application on W7 computer. And getting following exception:

Any idea what is wrong here ?

6 Answers 6

This type of exception is common when some part of your main window constructor or load operations fail. If you can get your hands on the stack trace, look to the inner exception and you will probably find the real issue.

I had this problem because I was showing a form from in Application constructor. This form was using Style=»«. This static resource was defined in the application’s XAML file.

I solved the problem by showing the form at a later stage in the application, when the Application object was fully constructed.

I had the same exception report. I could solve it by using the windbg program.

• download the windbg x86 (not x64) version.
• open the .exe file of the app in it (File menu -> open exe.)
• run these commands to see the real exception:

After the analysis, I found that the System.Net.Http.Formatting assembly was missing from the system.

the only thing I can think of is whether both boxes have same .NET version on it. NET 4 has some new features (re XAML parser) that 3.5 SP1 doesnt have

I noticed a similar behavior when installing a ClickOnce app on a clean machine. I solved by setting the requirements of the app for install both .Net 4 and .Net 3.5 full.

It was not happened anymore.

Make sure you are build in the correct architecture x86 or x64 when you run on the target machine. I face the same problem as well, the app able to run on my thumbdrive FAT32 however it failed on another machine with Windows 7 — 32bit (I know Windows 7 with 32bit is quite odd though) see http://social.msdn.microsoft.com/Forums/vstudio/en-US/8f803f28-dfda-4be5-9e8d-f7d82db95961/c-wpf-systemwindowsmarkupxamlparseexception?forum=wpf

Not the answer you’re looking for? Browse other questions tagged c# .net wpf xaml or ask your own question.

Related

Hot Network Questions

Subscribe to RSS

To subscribe to this RSS feed, copy and paste this URL into your RSS reader.

site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. rev 2021.4.16.39093

By clicking “Accept all cookies”, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy.

System.Windows.Markup.XamlParseException’ occurred in PresentationFramework.dll?

I’m using WPF on C# as code bellow

When I run the app, it will throw following exception

Line 9 is xmlns:customControl=»clr-namespace:DVRClientInterface.CustomControls» .

But I don’t know why, before that the XAML still work fine. I just edit the code in the C++ project, and after that it always throw that exception.

Many topics said that it was caused by the projects config, but I don’t know where in my projects config raise this exception.

Someone can suggest me how to fix it?

UPDATE: The output debug as below

7 Answers 7

This is not a problem with XAML. The error message is saying that it tried to create an instance of DVRClientInterface.MainWindow and your constructor threw an exception.

You will need to look at the «Inner Exception» property to determine the underlying cause. It could be quite literally anything, but should provide direction.

An example would be that if you are connecting to a database in the constructor for your window, and for some reason that database is unavailable, the inner exception may be a TimeoutException or a SqlException or any other exception thrown by your database code.

If you are throwing exceptions in static constructors, the exception could be generated from any class referenced by the MainWindow . Class initializers are also run, if any MainWindow fields are calling a method which may throw.

System.Windows.Markup.XamlParseException occurred

I have a datagrid bound to a list of objects. Users can add a new row below where the cursor is ( In code I create a new object and insert it in the list at the appropiate position).

Imagine that the datagrid has 4 rows

If the cursor is positioned in row number 4, then the row gets added, however, if the cursor is position in any of the other rows (1,2 or 3) then I get this exception:

System.Windows.Markup.XamlParseException occurred Message=»Root element is missing.» Source=»PresentationFramework» LineNumber=0 LinePosition=0 StackTrace: at System.Windows.Markup.XamlReaderHelper.RethrowAsParseException(String keyString, Int32 lineNumber, Int32 linePosition, Exception innerException) InnerException: System.Xml.XmlException Message=»Root element is missing.» Source=»System.Xml» LineNumber=0 LinePosition=0 SourceUri=»» StackTrace: at System.Xml.XmlTextReaderImpl.Throw(Exception e) at System.Xml.XmlTextReaderImpl.ParseDocumentContent() at System.Windows.Markup.XmlCompatibilityReader.Read() at System.Windows.Markup.XamlReaderHelper.Read(XamlNode& xamlNode) InnerException:

NOTE: when the app first loads, if i first add a row (by being in the last row), then i am also able to add a row from any of the other rows. However, if i first try to add a row from row numbers 1,2,3 then it fails!

Any help will be greatly appreciated. I am totally lost. I doubt anyone else has experienced this, but maybe you know what can be causing this or how I could debug it, as I do not know where to start 🙁

I have also notice that adding a row to the bottom does not fail

Xaml Parse Exception Class

Definition

Represents the exception class for parser-specific exceptions from a WPF XAML parser. This exception is used in XAML API or WPF XAML parser operations from .NET Framework 3.0 and .NET Framework 3.5, or for specific use of the WPF XAML parser by calling XamlReader API.

Remarks

XamlParseException is used only for the WPF-implemented XAML parser that performs the XAML parsing and loading for WPF applications. Specifically, the exception is only relevant when an application targets .NET Framework 3.0 and .NET Framework 3.5. The exception can also originate from user code in run-time calls to APIs that hook up the WPF-implemented XAML parser to load XAML from within a running WPF application (for example, calls to XamlReader.Load).

For .NET Framework 4, the XamlParseException exception that typically reports XAML processing exceptions is defined in a different namespace (System.Xaml) and a different assembly (System.Xaml).

Unless you are writing an equivalent to the WPF XAML parser or working with .NET Framework 3.0 and .NET Framework 3.5 targeting, you generally will not throw XamlParseException from your own code. However, handling for the exception is sometimes necessary. For application scenarios, where you may want to suppress XAML parse errors, a Dispatcher UnhandledException event handler at the application level is one way to handle a run-time XamlParseException. Whether to suppress exceptions or let them surface to user code depends on how you design your application for purposes of loading XAML, and the trust level that you assign to the XAML your application loads. For more information, see XAML Security Considerations or «XAML Security» section of XAML Overview (WPF).

For pages of an application, when the XamlParseException is thrown, it is usually in the context of the InitializeComponent call made by your page class, which is the entry point for the WPF application model’s usage of the WPF XAML parser at the per-page level. Therefore another possible handling strategy is to place try/catch blocks in InitializeComponent . However, this technique does not integrate well with templates, visual design surfaces and other generated sources that hook up InitializeComponent .

Constructors

Initializes a new instance of the XamlParseException class.

Initializes a new instance of the XamlParseException class.

Initializes a new instance of the XamlParseException class, using the specified exception message string.

Initializes a new instance of the XamlParseException class, using the specified exception message string and inner exception.

Initializes a new instance of the XamlParseException class, using the specified exception message string, and the specified line number and position in the line.

Initializes a new instance of the XamlParseException class, using the specified exception message, inner exception, line number, and position in the line.

Properties

Gets base URI information when the exception is thrown.

Gets a collection of key/value pairs that provide additional user-defined information about the exception.

(Inherited from Exception) HelpLink

Gets or sets a link to the help file associated with this exception.

(Inherited from Exception) HResult

Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception.

(Inherited from Exception) InnerException

Gets the Exception instance that caused the current exception.

(Inherited from Exception) KeyContext

Gets or sets the key value of the item in a dictionary where the exception occurred.

Gets the line number where the exception occurred.

Gets the position in the line where the exception occurred.

Gets a message that describes the current exception.

(Inherited from Exception) NameContext

Gets or sets the XAML name of the object where the exception occurred.

Gets or sets the name of the application or the object that causes the error.

(Inherited from Exception) StackTrace

Gets a string representation of the immediate frames on the call stack.

(Inherited from Exception) TargetSite

Gets the method that throws the current exception.

(Inherited from Exception) UidContext

Gets or sets the x:Uid Directive of the object where the exception occurred.

Methods

Determines whether the specified object is equal to the current object.

(Inherited from Object) GetBaseException()

When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions.

(Inherited from Exception) GetHashCode()

Serves as the default hash function.

(Inherited from Object) GetObjectData(SerializationInfo, StreamingContext)

Gets the data that is required to serialize the specified object by populating the specified SerializationInfo object.

Gets the runtime type of the current instance.

(Inherited from Exception) MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object) ToString()

Creates and returns a string representation of the current exception.

(Inherited from Exception)

Events

Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception.