CPF/CpfRazorSample/Test.razor


<Panel Background="#f00" Width="100" Height="100">
    <Panel Background="#00f" Width="20" Height="30" MouseDown="OnMouseDown">
    </Panel>        
    @if (visible)
    {
        <Panel Background="#0f0" Width="20" Height="30" MarginLeft="10"></Panel>
    }
</Panel>
@code
{
    bool visible = false;
    void OnMouseDown()
    {
        visible = !visible;
    }
}