I found it, the code is just fine and no need to call any redraw method, the only problem Any UI action need to be done in the MAIN thread
so the final code will be:
dispatch_async( dispatch_get_main_queue(), ^{
if (appState == 1) {
[self.splitView setFrameSize:CGSizeMake(self.splitView.frame.size.width, self.view.frame.size.height - 250)];
[self.mySubView1 setHidden:NO];
[self.mySubView2 setHidden:YES];
}
else
{
[self.splitView setFrameSize:CGSizeMake(self.splitView.frame.size.width, self.view.frame.size.height - 70)];
[self.mySubView1 setHidden:YES];
[self.mySubView2 setHidden:NO];
}
});
Thanks, guys.