Question

In a few words, how do I show a rectangle when the user moves the mouse over, inside of the rectangle I must show a user control.

I have no idea how to do that. Thanks for everything community.

Answer 1

If you mean that the user control should be seen all the time and the rectangle should only be seen when the mouse is over it? Then this works: (Border is used to draw a rectangle round another control.)

<Border Border.Background="Transparent" Border.BorderThickness="3">
    <Border.Style>
        <Style>
            <Setter Property="Border.BorderBrush" Value="Transparent"/>
            <Style.Triggers>
                <Trigger Property="Border.IsMouseOver" Value="True">
                    <Setter Property="Border.BorderBrush" Value="Green" />
                </Trigger>
            </Style.Triggers>
        </Style>
    </Border.Style>
    <TextBlock HorizontalAlignment="Center" VerticalAlignment="Center" Text="X" />
</Border>

(Make the border background transparent in order to capture mouse events inside the border)