With it, you can break into the Visual Tree and inspect the actual generated elements and their properties. The WPF Tree Visualizer comes built into Visual Studio, and is an essential tool to know about. To do this, you can call on an Attached Property PresentationSources.TraceLevel and set it for justįor more information on the Trace Levels and what they represent, Far better to target the specific binding where the error is. If you increase the trace level that way, you will get a WHOLE LOAD of messages for everything. (click to enlarge) 2. Changing Trace Level on a Specific Binding In there you can change theĭataBinding output settings to Verbose or 1. Changing Trace Level for All in OptionsĬlick the Visual Studio menu Tools / Options, then openĭebugging and Output Window. Sometimes you will need a more detailed debugging output for binding. In this example, the property name was misspelled with a 'z'. This is when the property name in the binding expression is wrong, or the property does not exist in the source object. (Name='') target property is 'ItemsSource' (type 'IEnumerable')" BindingExpression:Path=MyStringOptionz DataItem='MainWindow' (Name='Window') target element is 'ComboBox' " Error: 40 : BindingExpression path error: 'MyStringOptionz' property not found on 'object' ''MainWindow' (Name='Window')'. In this example, the error was because the source is a Window, not a UserControl. It is erroring when looking for the binding source, in other words the physical object to find the property on. I am binding its ItemsSource to a property called PartIds. This is a ComboBox inside a DataGridTemplateColumn. (Name='') target property is 'ItemsSource' (type 'IEnumerable') BindingExpression:Path=PartIds DataItem=null target element is 'ComboBox' Error: 4 : Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='', AncestorLevel='1''. Although the errors seem obscure at first, there are only a few common ones and they are quite helpful messages.īelow are some typical errors and an explanation for each. When an error occurs in the binding framework, the notification is usually "silent", in that is doesn't pop up an error dialog to the user. This article will cover some of the methods for analyzing your WPF application, troubleshooting issues, and debugging seemingly obscure errors. Goes wrong in that autogenerated super-sexy front-end, it is not always clear where the problem is. Net programming all make for a very rapid development cycle. Animations, bindings, reskinnable codeless interfaces, all backed up with traditional. Windows Presentation Foundation (WPF) is a joy to develop rich user experiences with.