1.我们在非视图类中想要随时展示一个view时,需要将被展示的view加到当前view的子视图,或用当前view presentViewController,或pushViewContrller,这些操作都需要获取当前正在显示的ViewController。
//获取当前屏幕显示的viewcontroller - (UIViewController *)getCurrentVC { UIViewController *result = nil; UIWindow * window = [[UIApplication sharedApplication] keyWindow]; if (window.windowLevel != UIWindowLevelNormal) { NSArray *windows = [[UIApplication sharedApplication] windows]; for(UIWindow * tmpWin in windows) { if (tmpWin.windowLevel == UIWindowLevelNormal) { window = tmpWin; break; } } } UIView *frontView = [[window subviews] objectAtIndex:0]; id nextResponder = [frontView nextResponder]; if ([nextResponder isKindOfClass:[UIViewController class]]) result = nextResponder; else result = window.rootViewController; return result; }
2.获取当前屏幕中present出来的viewcontroller。
- (UIViewController *)getPresentedViewController { UIViewController *appRootVC = [UIApplication sharedApplication].keyWindow.rootViewController; UIViewController *topVC = appRootVC; if (topVC.presentedViewController) { topVC = topVC.presentedViewController; } return topVC; }