iOS7中实现子视图旋转方向控制

   为了能够让父视图（地图视图）实现随意旋转，而子视图按照某种固定的方向（竖屏）显示寻找了好些方案，最后发现在iOS7中其实很简单

-(BOOL)shouldAutorotate{
    if([[UIDevice currentDevice] orientation] == UIInterfaceOrientationLandscapeLeft ||[[UIDevice currentDevice] orientation] == UIInterfaceOrientationLandscapeRight)
    {
        return NO;
    }
    else{
        return YES;
    }
}

另外有人在iOS6中使用如下方式

static CGSize appScreenSize;
static UIInterfaceOrientation lastOrientation;
 
+(CGSize) screenSize{
UIInterfaceOrientation orientation =[UIApplication sharedApplication].statusBarOrientation;
if(appScreenSize.width==0 || lastOrientation != orientation){
appScreenSize = CGSizeMake(0, 0);
CGSize screenSize = [[UIScreen mainScreen] bounds].size; // 这里如果去掉状态栏，只要用applicationFrame即可。
if(orientation == UIDeviceOrientationLandscapeLeft ||orientation == UIDeviceOrientationLandscapeRight){
// 横屏，那么，返回的宽度就应该是系统给的高度。注意这里，全屏应用和非全屏应用，应该注意自己增减状态栏的高度。
appScreenSize.width = screenSize.height;
appScreenSize.height = screenSize.width;
}else{
appScreenSize.width = screenSize.width;
appScreenSize.height = screenSize.height;
}
lastOrientation = orientation;
}
return appScreenSize;
}