iOS 獲取當(dāng)前正在顯示的ViewController,方法有如下幾種
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(gè)日常的需求:在UITableviewcell里面的UIView模塊里面卸留，調(diào)用self.navigationcontroller pushviewcontroller推入一個(gè)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(shí)展示一個(gè)view時(shí)青团，需要將被展示的view加到當(dāng)前view的子視圖兔毒，或用當(dāng)前view presentViewController，或pushViewContrller瑟匆，這些操作都需要獲取當(dāng)前正在顯示的ViewController闽坡。
//獲取當(dāng)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(dāng)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
