在iOS7.0以后，UIViewController添加了automaticallyAdjustsScrollViewInsets，关于此属性的描述看官方文档解释

automaticallyAdjustsScrollViewInsets

 Property

A Boolean value that indicates whether the view controller should automatically adjust its scroll view insets.

Declaration

SWIFT

var automaticallyAdjustsScrollViewInsets: Bool

OBJECTIVE-C

@property(nonatomic, assign) BOOL automaticallyAdjustsScrollViewInsets

Discussion

The default value of this property is YES, which allows the view controller to adjust its scroll view insets in response to the screen areas consumed by the status bar, navigation bar, and toolbar or tab bar. Set to NO if you want to manage scroll view inset adjustments yourself, such as when there is more than one scroll view in the view hierarchy.

Availability

Available in iOS 7.0 and later.

当我们在VC视图中添加一个UIScrollView,设置起frame为（0，0，320，568），在UIScrollview上添加子视图A，设置A的坐标为（0，0，100，17），但实际显示得到的效果，看起来是A的坐标为（0，64，100，17）。此时只要设置automaticallyAdjustsScrollViewInsets为NO，就可以得到正确的坐标效果。

 

automaticallyAdjustsScrollViewInsets 属性默认会给scrollview自动适应屏幕