ios:屏幕旋转

在.m文件中修改方法 - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

 默认为竖屏：

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

{

    return (interfaceOrientation != UIInterfaceOrientationPortrait);//竖屏

} 

修改后为： 

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

{

    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);//不支持倒置竖屏

}