Useless information

Assume that I want to write a handler for this event. Where do I find the interface description?
The new documnetation is all to often totally useless lacking substantial information and examples.

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#### Document Details

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* ID: f2c2a4b4-423c-e2b5-8dec-bd8c0f046b7c
* Version Independent ID: 30a347cb-8b49-334e-1b3d-192e57bffe5b
* Content: [FrameworkElement.DataContextChanged Event (System.Windows)](https://docs.microsoft.com/en-us/dotnet/api/system.windows.frameworkelement.datacontextchanged?view=netframework-4.7.1)
* Content Source: [xml/System.Windows/FrameworkElement.xml](https://github.com/dotnet/dotnet-api-docs/blob/master/xml/System.Windows/FrameworkElement.xml)
* Service: **unspecified**
* GitHub Login: @dotnet-bot
* Microsoft Alias: **dotnetcontent**

Inizia dalla pagina API collegata di FrameworkElement.DataContextChanged e dal relativo codice sorgente in xml/System.Windows/FrameworkElement.xml. Determina quali dettagli sull’interfaccia e quali esempi mancano, quindi aggiorna la documentazione dell’API in modo che l’evento sia spiegato in modo esaustivo e includa esempi utili; verifica infine la pagina renderizzata.

Scritto dal modello di indicizzazione a partire dal testo della issue.