Diffrent style for first three rows of WPF ListView

Question

I want the top three items in my ListView to have special style. How can i achieve this?

I have tried this but item is always null:

                    if (tracklistQueue.Items.Count > 0) {
                         ListViewItem item = (ListViewItem)tracklistQueue.ItemContainerGenerator.ContainerFromIndex(0);
                         item.Style = (Style)FindResource("StyleName");
                    }  

Answer 1

Solved it. The ItemContainerGenerator had not finished generating the items.

Added this to the constructor and put the code there:

this.tracklistQueue.ItemContainerGenerator.StatusChanged += new EventHandler(ItemContainerGenerator_StatusChanged);

Answer 2

You can use AlternationIndex and AlternationCount properties.

Following example sets different background color for first three rows.

Add this style definition to your UserControl (or Window):

<Style TargetType="ListViewItem">
    <Style.Triggers>
        <Trigger Property="ItemsControl.AlternationIndex" Value="0">
            <Setter Property="Background" Value="#FFFF0000" />
        </Trigger>
        <Trigger Property="ItemsControl.AlternationIndex" Value="1">
            <Setter Property="Background" Value="#FF00FF00" />
        </Trigger>
        <Trigger Property="ItemsControl.AlternationIndex" Value="2">
            <Setter Property="Background" Value="#FF0000FF" />
        </Trigger>
    </Style.Triggers>
</Style>

Set AlternationCount of ListView to value which is greater than number of rows that ListView can actually contain:

<ListView AlternationCount="1000" />

Reference:

ItemsControl.AlternationCount Property