PropertyDefinition IsExpanded binding have no effect

[rui]

I use a checkbox PropertyDefinition  which contains NestedProperties,  I want to achieve the checkbox and the expand keep the same status, when the checkbox is checked the nestedProperties expand and when the checkbox is unchecked the nestedProperties unexpand    the code is as follow

                <telerik:PropertyDefinition
                                            Binding="{Binding ​IsShowDetail}"
                                            IsExpanded="{Binding ​IsShowDetail}">
                    <telerik:PropertyDefinition.NestedProperties>
                        <telerik:PropertyDefinition Binding="{Binding Path=Name,
                                                                      Mode=TwoWay}"/>
                        <telerik:PropertyDefinition Binding="{Binding Path=Description,
                                                                      Mode=TwoWay}"/>
                    </telerik:PropertyDefinition.NestedProperties>
                </telerik:PropertyDefinition>

 The "IsShowDetail " is a bool property,  the "Binging "and "IsExpanded "both binding to this property

but the "IsExpanded "have no effect

what is the reason for this and how to achieve this effect?

thanks 

[Ivan Ivanov]

Hi,

PropertyDefinition derives from DependencyObject. Thus it supports data binding, but it does not have a default binding source (DataContext). So that you have to defined the source for the IsExpanded binding explicitly. You can expose the assigned Item/ViewModel instance as a StaticResource and refer to it in the binding definition.
The "Binding" property works with data bindinng without specifying explicit source, because it gets assigned to the respective editor control, which generally derives from FrameworkElement and FrameworkElelement supports DataContext. RadPropertyGrid internally assigns the Item as a DataContext for its editors.

Regards,
Ivan Ivanov
Telerik

[Lakshman]

Hello @Ivan Need an example to bind the IsExpandedProperty and want to add few logical steps depending on expand or collapse of the dropdown of it.

 

Below is the code snippit what i had written:

public bool IsExpanded
        {
            set
            {
                isExpanded = value;
            }

            get
            {
                return isExpanded;
            }
        }

var tagProperty = new CollectionPropertyDefinition()

Binding myBinding = new Binding("IsExpanded");
myBinding.Source = this;
BindingOperations.SetBinding(tagProperty, CollectionPropertyDefinition.IsExpandedProperty, myBinding);

 

The setter need be triggered when dropdown is expanded or collapsed.

 

Thank You,

Lakshman Siddireddy

[Vera]

Hi Lakshman,

In order to trigger the setter of IsExpanded property TwoWay binding have to be set like so:

 myBinding.Mode = BindingMode.TwoWay;

Let me know if you have any other issues.

Regards,
Vera
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