System.Windows.Markup.XamlParseException

Question

System.Windows.Markup.XamlParseException

Jose Carlos Cruz Santiago 0

Buenos días, estoy desarrollando una solución con .NET, para ello empleo WPF y CommunityToolkit.Mvvm v8.2.0, y al ejecutarlo me arroja en ocasiones la siguiente excepción System.Windows.Markup.XamlParseException.

Quisiera saber como puedo solucionar este problema.

Error

gekka 12,206 Reputation points MVP Volunteer Moderator

2023-12-09T23:54:01.4533333+00:00

Exception says 'Must create DependencySource on same Thread as the DependencyObject'

Are you doing anything between multi-threads?
Hui Liu-MSFT 48,676 Reputation points Microsoft External Staff

2023-12-11T03:00:42.4833333+00:00
Hi,@Jose Carlos Cruz Santiago. Welcome to Microsoft Q&A Forum. This is an English forum. Please ask your question in English.

The error message "Must create DependencySource on the same Thread as the DependencyObject" typically occurs in the context of multi-threaded programming in applications that use the Windows Presentation Foundation framework. WPF has a threading model that requires certain operations to be performed on the same thread that the UI element was created on.

Here are some common reasons why you might encounter this exception:

Accessing UI Elements from the Wrong Thread:

Ensure that any operations that involve UI elements (such as modifying properties of a DependencyObject) are performed on the UI thread.

WPF has a dispatcher mechanism that allows you to marshal operations to the UI thread using the Dispatcher class.

Example of using the Dispatcher to update a UI element from a non-UI thread:

Application.Current.Dispatcher.Invoke(()=> { myDependencyObject.Property=value; }

Cross-Thread Object Access:

Avoid directly accessing UI elements or their properties from a background thread. Using the dispatcher to marshal the operation to the UI thread.

Data Binding Across Threads:

If you are using data binding, make sure that the data source and the UI element are accessed on the same thread. This is particularly important if you are updating data on a background thread that is bound to UI elements.

Your answer

gekka 12,206 Reputation points MVP Volunteer Moderator

2023-12-09T23:54:01.4533333+00:00

Exception says 'Must create DependencySource on same Thread as the DependencyObject'

Are you doing anything between multi-threads?
Hui Liu-MSFT 48,676 Reputation points Microsoft External Staff

2023-12-11T03:00:42.4833333+00:00

Hi,@Jose Carlos Cruz Santiago. Welcome to Microsoft Q&A Forum. This is an English forum. Please ask your question in English.

The error message "Must create DependencySource on the same Thread as the DependencyObject" typically occurs in the context of multi-threaded programming in applications that use the Windows Presentation Foundation framework. WPF has a threading model that requires certain operations to be performed on the same thread that the UI element was created on.

Here are some common reasons why you might encounter this exception:

Accessing UI Elements from the Wrong Thread:

Ensure that any operations that involve UI elements (such as modifying properties of a DependencyObject) are performed on the UI thread.

WPF has a dispatcher mechanism that allows you to marshal operations to the UI thread using the Dispatcher class.

Example of using the Dispatcher to update a UI element from a non-UI thread:

Application.Current.Dispatcher.Invoke(()=> { myDependencyObject.Property=value; }

Cross-Thread Object Access:

Avoid directly accessing UI elements or their properties from a background thread. Using the dispatcher to marshal the operation to the UI thread.

Data Binding Across Threads:

If you are using data binding, make sure that the data source and the UI element are accessed on the same thread. This is particularly important if you are updating data on a background thread that is bound to UI elements.

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System.Windows.Markup.XamlParseException

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