1:從UIWindow中獲取
#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:從UIView里面獲取
//滿足一個日常的需求:在UITableviewcell里面的UIView模塊里面，調用self.navigationcontroller pushviewcontroller推入一個新的viewcontroller，需要獲取其上層的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:從UIViewController中獲取
#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;
}
//我們在非視圖類中想要隨時展示一個view時，需要將被展示的view加到當前view的子視圖，或用當前view presentViewController，或pushViewContrller，這些操作都需要獲取當前正在顯示的ViewController。
//獲取當前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;
}
//獲取當前屏幕中present出來的viewcontroller。
- (UIViewController *)getPresentedViewController
{
UIViewController *appRootVC = [UIApplication sharedApplication].keyWindow.rootViewController;
UIViewController *topVC = appRootVC;
if (topVC.presentedViewController) {
topVC = topVC.presentedViewController;
}
return topVC;
}
@end
友情隨便跳轉
-(void)pushTest {? ? [self.navigationController pushViewController:D animated:YES];
NSMutableArray*tempMarr = [NSMutableArrayarrayWithArray : self.navigationController.viewControllers]; ?
??[tempMarr insertObject:C atIndex:tempMarr.count- 2];?
? ?[tempMarr removeObject:self]; //此時 的self 就是指 B ,因為在 B 中呢 ?
??[self.navigationController setViewControllers:tempMarr animated:YES];}
