IOS-翻转时，使用2个view的交换（需注意）

- (void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)
interfaceOrientation duration:(NSTimeInterval)duration {
    if (interfaceOrientation == UIInterfaceOrientationPortrait) {
        self.view = self.portrait;
        self.view.transform = CGAffineTransformIdentity;
        self.view.transform =
        CGAffineTransformMakeRotation(degreesToRadians(0));
        self.view.bounds = CGRectMake(0.0, 0.0, 320.0, 460.0);//纵方向-20
    }
    else if (interfaceOrientation == UIInterfaceOrientationLandscapeLeft) {
        self.view = self.landscape;
        self.view.transform = CGAffineTransformIdentity;
        self.view.transform =
        CGAffineTransformMakeRotation(degreesToRadians(-90));
        self.view.bounds = CGRectMake(0.0, 0.0, 480.0, 300.0);
    }
    else if (interfaceOrientation ==
             UIInterfaceOrientationPortraitUpsideDown) {
        self.view = self.portrait;
        self.view.transform = CGAffineTransformIdentity;
        self.view.transform =
        CGAffineTransformMakeRotation(degreesToRadians(180));
        self.view.bounds = CGRectMake(0.0, 0.0, 320.0, 460.0);
    }
    else if (interfaceOrientation ==
             UIInterfaceOrientationLandscapeRight) {
        self.view = self.landscape;
        self.view.transform = CGAffineTransformIdentity;
        self.view.transform =
        CGAffineTransformMakeRotation(degreesToRadians(90));
        self.view.bounds = CGRectMake(0.0, 0.0, 480.0, 300.0);
    }
}