Thanx, Jacob!
I`l tried one more time and find solution. In this lines:
Streamer->SetTargetViewport(TargetViewport->GetViewportWidget());
Streamer->SetTargetWindow(TargetViewport->FindWindow());
we need change to
this->SetTargetViewport(TargetViewport->GetViewportWidget());
this->SetTargetWindow(TargetViewport->FindWindow());