_myTimer = [NSTimer timerWithTimeInterval:3.0 target:self selector:@selector(timerFired) userInfo:nil repeats:NO];
[[NSRunLoop currentRunLoop] addTimer:_myTimer forMode:NSDefaultRunLoopMode];
[_myTimer invalidate];移除timer
3秒后执行
-(void)timerFired
{
DebugLog(@"ok");
UIWindow *window = [UIApplication sharedApplication].keyWindow;
window.rootViewController = [[WrapperMainViewController alloc] init];
}