WPF - Making Databound ListViewColumns Resize When Adding Item

I'm making an WPF-application that has a databound ListView. When loading the application, the width of the ListViewColumns will auto-resize, but when adding or changing an item it doesn't auto-resize. I've tried refreshing the listview, setting the width of the column to auto, -1 or -2 in both xaml and VB-code and I've tries changing the itemssource to nothing before refilling it with items.

This is the xaml code:
<ListView x:Name="lsvPersons" Margin="5,5,5,35" ItemsSource="{Binding Persons}">
<ListView.View><GridView>
<GridViewColumn DisplayMemberBinding="{Binding Name}" Header="Name"/>
<GridViewColumn DisplayMemberBinding="{Binding Gender}" Header="Gender"/>
<GridViewColumn DisplayMemberBinding="{Binding Age}" Header="Age"/>
[Code] .....

After pressing the button, a window will open to add a person. After the window is closed, the item is added to the listview with following code, which refreshes the items in the listview:
lsvPersons.ItemsSource = Person.getPersons()
So, what do I need to do to auto-resize the columns of the listview when an item is added or edited?