如何更新UIImageView的contentMode？

Question

在最初的UIImageView我把它設置爲

mCurrentImageView.contentMode = UIViewContentModeLeft; 

因此，如果設備旋轉我會改變contentMode ，但它沒有任何效果。我該如何解決它？

if ([UIDevice currentDevice].orientation == UIInterfaceOrientationLandscapeLeft || [UIDevice currentDevice].orientation == UIInterfaceOrientationLandscapeRight) { 
     mCurrentImageView.contentMode = UIViewContentModeScaleAspectFit; 
    } 

Answer 1

[UIDevice orientation]不返回這些標識符的方向。從文檔，該消息將返回以下：

typedef enum { 
    UIDeviceOrientationUnknown, 
    UIDeviceOrientationPortrait, 
    UIDeviceOrientationPortraitUpsideDown, 
    UIDeviceOrientationLandscapeLeft, 
    UIDeviceOrientationLandscapeRight, 
    UIDeviceOrientationFaceUp, 
    UIDeviceOrientationFaceDown 
} UIDeviceOrientation; 

要改變內容模式，你應該做的視圖控制器代碼東西willRotate消息：

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration { 
    if (toInterfaceOrientation == UIInterfaceOrientationLandscapeLeft || toInterfaceOrientation == UIInterfaceOrientationLandscapeRight) { 
     mCurrentImageView.contentMode = UIViewContentModeScaleAspectFit; 
    } 
}