bounds

问题 In order to setup a query to an external server I want to get the bounds of the current Map View in an iPhone app I\'m building. UIView should respond to bounds but it seems MKMapView doesn\'t. After setting a region and zooming in the map I try to get the bounds. I\'m stuck on the first step which is to try to get the CGPoints that represent the SE and NW corners of the map. After that I was going to use: - (CLLocationCoordinate2D)convertPoint:(CGPoint)point toCoordinateFromView:(UIView *

问题 I would like to know how to use the UIView property clipsToBounds . The official documentation says the following: clipsToBounds property A Boolean value that determines whether subviews are confined to the bounds of the view. Discussion Setting this value to YES causes subviews to be clipped to the bounds of the receiver. If set to NO , subviews whose frames extend beyond the visible bounds of the receiver are not clipped. The default value is NO . But I\'m unclear on what this means exactly

问题 UIView has the properties frame , bounds , center , and origin , and they all seem to be interrelated. Most of the time, I deal with frame when setting the position and size of a UIView . I understand that frame is using global coordinate system and bounds is using coordinate of the local view (therefore its x and y are 0, but not always), but it\'s still confusing to me when to use what. Under what context (and what\'s the right time) the other properties ( bounds , center , origin ) should

问题 I gather that you cannot bind a Java generics type parameter to a lower bound (i.e. using the super keyword). I was reading what the Angelika Langer Generics FAQ had to say on the subject. They say it basically comes down to a lower bound being useless (\"not making any sense\"). I\'m not convinced. I can imagine a use for them to help you be more flexible to callers of a library method that produces a typed result. Imagine a method that created an array list of a user-specified size and

问题 I have a custom view that\'s not getting layoutSubview messages during animation. I have a view that fills the screen. It has a custom subview at the bottom of the screen that correctly resizes in Interface Builder if I change the height of the nav bar. layoutSubviews is called when the view is created, but never again. My subviews are correctly laid out. If I toggle the in-call status bar off, the subview\'s layoutSubviews is not called at all, even though the main view does animate its

问题 I would like to know how to use these properties in the right manner. As I understand, frame can be used from the container of the view I am creating. It sets the view position relative to the container view. It also sets the size of that view. Also center can be used from the container of the view I\'m creating. This property changes the position of the view relative to its container. Finally, bounds is relative to the view itself. It changes the drawable area for the view. Can you give more