PreivewClose and Close Events - MVVM

Here are my interaction trigger.

 <i:Interaction.Triggers>
                    <i:EventTrigger EventName="PreviewClose">
                        <cmd:EventToCommand Command="{Binding PreviewCloseCommand}" CommandParameter="{Binding ElementName=ContentContainer}" />
                    </i:EventTrigger>
                    <i:EventTrigger EventName="Close">
                        <cmd:EventToCommand Command="{Binding CloseCommand}" CommandParameter="{Binding ElementName=ContentContainer}" />
                    </i:EventTrigger>
                </i:Interaction.Triggers>