Hide HeaderContent from the top of a ListView - wpf

Question

I have a
<DockPanel>
<!-- Header -->
<Button DockPanel.Dock="Top" Command="{Binding CreateAccountCommand}" Margin="{StaticResource ControlMargin}" Style="{StaticResource IconButtonStyle}">
<StackPanel>
<MahAppsIconPacks:PackIconFontAwesome Kind="Pencil" />
<TextBlock>create account</TextBlock>
</StackPanel>
</Button>
<!-- Accounts list -->
<ListView SelectionMode="Single" SelectedIndex="0" ItemsSource="{Binding AccountViewModels}" SelectedItem="{Binding SelectedItem}" Style="{StaticResource AccountsList}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<LocalViews:AccountView Margin="{StaticResource ControlMargin}" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ListView>
</DockPanel>
It renders with a black separator on top of it, which is quite ugly. How do I hide it? I have tried setting different styles, but there is no ListViewColumnHeader.
In the live tree it shows as header content ... not separator, my bad. How do I remove it?
This doesn't work:
<Style TargetType="ListView" x:Key="AccountsList" BasedOn="{StaticResource {x:Type ListView}}">
<Style.Resources>
<Style TargetType="HeaderedContentControl">
<Setter Property="Visibility" Value="Collapsed" />
</Style>
</Style.Resources>
</Style>

Answer 1

Are you using any of the View capabilities of ListView? (e.g. GridView etc which I believe is the default. In which case, the separator is probably the header section, but empty). If you're not, try just using a ListBox instead. It has no header as default.
Edit: I just checked this theory, but it appears I can't reproduce your issue at all. Here's a ListBox as you've got your code (and a ListView for good measure):
<Window.Resources>
<x:Array x:Key="Items" Type="sys:String">
<sys:String>Item 1</sys:String>
<sys:String>Item 2</sys:String>
<sys:String>Item 3</sys:String>
</x:Array>
</Window.Resources>
<StackPanel Margin="20">
<TextBlock Text="ListBox:"/>
<ListBox Height="100" ItemsSource="{StaticResource Items}" BorderBrush="Transparent">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding}"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ListBox>
<TextBlock Text="ListView:"/>
<ListView Height="100" ItemsSource="{StaticResource Items}" BorderBrush="Transparent">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding}"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ListView>
</StackPanel>
It may be the different themes on Windows 7 however, I'm using Windows 10.

Answer 2

I believe this is a result of the MahApps template. It's not the default behaviour of a standard WPF ListView.
You would have to adjust the MahApps template to get rid of it.
Something like this:
<Style TargetType="{x:Type ListView}" BasedOn="{StaticResource {x:Type ListView}}">
<Setter Property="BorderThickness" Value="0" />
</Style>
The MahApps code and resources are all open source. I think the particular problem you are having is driven by the BorderThickness setter here:
https://github.com/MahApps/MahApps.Metro/blob/develop/src/MahApps.Metro/MahApps.Metro/Styles/Controls.ListView.xaml
<Style x:Key="MetroListView" TargetType="{x:Type ListView}">
<Setter Property="OverridesDefaultStyle" Value="true" />
<Setter Property="AlternationCount" Value="2" />
<Setter Property="Background" Value="{DynamicResource WhiteBrush}" />
<Setter Property="BorderBrush" Value="{DynamicResource BlackBrush}" />
<Setter Property="BorderThickness" Value="0 1 0 0" />