Wpf binding datacontext null

This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. Framework Element. Data Context Property Reference Is this page helpful? Please rate your experience Yes No. Any additional feedback? Namespace: System. Data namespace. Fallback values are used to get or set the value when binding, unable to return a value and when binding fails. If there is a problem with binding or not able to resolve the binding source successfully at that time Fallback values are very useful.

In this example, we can add a source of every image in our project but if any reason that our binding can fail and we want to display our default image so at that moment Fallback value is used. Here is a string, bool, int data type now we can set it to null and add their data in target null value. This is simple binding using this binding format we can get null values.

Solution - TargetNullValue This is where we use TargetNullValue: TargetNullValue is set to thecontrol's bound property when the value of the bound property also known as source property is null for some reason. In layman's terms, when the target is null, this property will be assigned.

Note: string is already null so TargetNullvalue will be triggered. Note: we can't set DateTime to null so have to make nullable DateTime. Note: we can't set int to null so have to make nullable int.

Note: we can't set the bool to null so have to make nullable bool. TargetNullValues have been successfully applied when source property was null for all 4 kinds of datatypes.

New Problem!! That is cool, we can now handle a situation when source value is null and can make sense out of data with TargetNullValues. But what if there is a typo in bound property or our application fails to bind property for any reason.

In such a case, we will have no data to display. In our application let's say we change the bound properties name and let's add FallBackValues to those controls. It works well. DataContext null when the controls are initiated? Hi again, During my evaluation I have encountered a very strange bahavior. Why is this happening? Is there a way to avoid it? Reply Cancel.