iOS7中實現子視圖旋轉方向控制

   為了能夠讓父視圖（地圖視圖）實現隨意旋轉，而子視圖按照某種固定的方向（豎屏）顯示尋找了好些方案，最後發現在iOS7中其實很簡單

-(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; // 這裡如果去掉狀態列，只要用applicationFrame即可。if(orientation == UIDeviceOrientationLandscapeLeft ||orientation == UIDeviceOrientationLandscapeRight){// 橫屏，那麼，返回的寬度就應該是系統給的高度。注意這裡，全屏應用和非全屏應用，應該注意自己增減狀態列的高度。appScreenSize.width = screenSize.height;appScreenSize.height = screenSize.width;}else{appScreenSize.width = screenSize.width;appScreenSize.height = screenSize.height;}lastOrientation = orientation;}return appScreenSize;}