iOS 获取当前正在显示的

iOS 获取当前正在显示的ViewController,方法有如下几种

---

1. 从UIWindow中获取

#import "UIWindow+SHHelper.h"

@implementation UIWindow (SHHelper)

- (UIViewController*)sh_topMostController

{

//  getting rootViewController

UIViewController *topController = [self rootViewController];

//  Getting topMost ViewController

while ([topController presentedViewController]) topController = [topController presentedViewController];

//  Returning topMost ViewController

return topController;

}

- (UIViewController*)sh_currentViewController;

{

UIViewController *currentViewController = [self sh_topMostController];

while ([currentViewController isKindOfClass:[UINavigationController class]] && [(UINavigationController*)currentViewController topViewController])

currentViewController = [(UINavigationController*)currentViewController topViewController];

return currentViewController;

}

@end

2. 从UIView里面获取

//满足一个日常的需求:在UITableviewcell里面的UIView模块里面，调用self.navigationcontroller pushviewcontroller推入一个新的viewcontroller，需要获取其上层的UIViewcontroller, 可以使用下面的方法:

- (UIViewController *)sh_viewController

{

UIResponder *responder = self;

while ((responder = [responder nextResponder])){

if ([responder isKindOfClass: [UIViewController class]]){

return (UIViewController *)responder;

}

}

return nil;

}

3. 从UIViewController中获取

#import "UIViewController+SHHelper.h"

@implementation UIViewController (SHHelper)

- (UIViewController*)sh_topMostController

{

UIViewController *topController = self ;

while ([self presentedViewController])

topController = [topController presentedViewController];

return topController;

}

- (UIViewController*)sh_currentViewController;

{

UIViewController *currentViewController = [self sh_topMostController];

while ([currentViewController isKindOfClass:[UINavigationController class]] && [(UINavigationController*)currentViewController topViewController])

currentViewController = [(UINavigationController*)currentViewController topViewController];

return currentViewController;

}

//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view的UIViewController

+ (UIViewController *)sh_currentViewControllerFromcurrentView{

UIViewController *result = nil;

// 1. get current window

UIWindow * window = [[UIApplication sharedApplication] keyWindow];

if (window.windowLevel != UIWindowLevelNormal) {

NSArray *windows = [[UIApplication sharedApplication] windows];

for(UIWindow * tempWindow in windows) {

if (tempWindow.windowLevel == UIWindowLevelNormal) {

window = tempWindow;

break;

}

}

}

// 2. get current View Controller

UIView *frontView = [[window subviews] objectAtIndex:0];

id nextResponder = [frontView nextResponder];

if ([nextResponder isKindOfClass:[UIViewController class]]) {

result = nextResponder;

} else {

result = window.rootViewController;

}

return result;

}

//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;

}

@end