self.view.window 只是当前view的window,可能是keywindow
@property(nonatomic, readonly) UIWindow *window
Description
The receiver’s window object, or nil if it has none. (read-only)
This property is nil if the view has not yet been added to a window.
[[UIApplication sharedApplication] keyWindow]
@property(nonatomic, readonly) UIWindow *keyWindow
This property holds the UIWindow object in the windows array that is most recently sent the makeKeyAndVisible message.
[[UIApplication sharedApplication] windows]
@property(nonatomic, readonly) NSArray *windows
This property returns an array of the application's visible and hidden windows. The windows are ordered back to front.
I think UIView.window returns the window where the current view is located, not necessarily the keywindow
In case view is a certain area on the keyboard, view.window is the window of the keyboard.
Not necessarily.
Can be judged by view.window.keyWindow.