//设定5秒后执行disconnect方法
[self performSelector:@selector(disconnect:) withObject:nil afterDelay:5];
//取消disconnect的延时执行
[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(disconnect:) object:nil];
//设定5秒后执行disconnect方法
[self performSelector:@selector(disconnect:) withObject:nil afterDelay:5];
//取消disconnect的延时执行
[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(disconnect:) object:nil];