Default is, obviously, the default value of the Update Source Trigger.The other options are Property Changed, Lost Focus and Explicit. I tried letting the underlying value appear to change so that I could change it back to the original value on a Begin Invoke operation. I would think that simply raising Property Changed would tell WPF that to re-query the value.
Since WPF 4.5, the Binding has a new property named ‘Delay’ which defines a timespan after which the source is updated. As this is an added property on the Binding, you only have to define it on each Binding you create.I have defined a Standards property of type Ilist Since we are using the MVVM approach here in this article, that is why we cannot have Selection Changed event for my combobox which prevents me to achieve MVVM design.That is why I have Selected Item property defined, the setter of Selected Standard is invoked when I change the selection.as the control’s new Items Source causes the control to display the revised data and…whoa…clears the currently selected item.From the technical perspective, this clearing makes sense.Selected Item, Selected Value and Display Member Path. Selected Item – Selected Item helps to bind the actual value from the Data Source which will be displayed.