public override void ChannelDown()
{
if (CurrentChannelIndex == 0)
{
Channel = KnownChannels.Items[KnownChannels.Items.Count - 1];
}
else if (CurrentChannelIndex > -1)
{
Channel = KnownChannels.Items[CurrentChannelIndex - 1];
}
else
{
int virtualIndex = KnownChannels.FindClosestIndex(Channel);
Channel = KnownChannels.Items[virtualIndex - 1];
}
}