获取当前viewController及当前view的viewCo

1. 获取当前viewController

// 方法一：
- (UIViewController *)getCurrentViewController
{
    UIViewController *result = nil;
    // 获取默认的window
    UIWindow * window = [[UIApplication sharedApplication] keyWindow];
    // app默认windowLevel是UIWindowLevelNormal，如果不是，找到它。
    if (window.windowLevel != UIWindowLevelNormal) {
        NSArray *windows = [[UIApplication sharedApplication] windows];
        for(UIWindow * tmpWin in windows) {
            if (tmpWin.windowLevel == UIWindowLevelNormal) {
                window = tmpWin;
                break;
            }
        }
    }
    
    // 获取window的rootViewController
    result = window.rootViewController;
    while (result.presentedViewController) {
        result = result.presentedViewController;
    }
    if ([result isKindOfClass:[UITabBarController class]]) {
        result = [(UITabBarController *)result selectedViewController];
    }
    if ([result isKindOfClass:[UINavigationController class]]) {
        result = [(UINavigationController *)result visibleViewController];
    }
    return result;
}

// 方法二：
UIViewController *getCurrentViewController(void) {
    UIWindow *window = [[UIApplication sharedApplication].delegate window];
    UIViewController *topViewController = [window rootViewController];
    
    while (true) {
        
        if (topViewController.presentedViewController) {
            
            topViewController = topViewController.presentedViewController;
            
        } else if ([topViewController isKindOfClass:[UINavigationController class]] && [(UINavigationController*)topViewController topViewController]) {
            
            topViewController = [(UINavigationController *)topViewController topViewController];
            
        } else if ([topViewController isKindOfClass:[UITabBarController class]]) {
            
            UITabBarController *tab = (UITabBarController *)topViewController;
            topViewController = tab.selectedViewController;
            
        } else {
            break;
        }
    }
    return topViewController;
}

2.获取当前view的viewController

UIViewController *getViewControllerWithView(UIView *view){
    UIResponder *responder = view;
    while ((responder = [responder nextResponder]))
        if ([responder isKindOfClass: [UIViewController class]])
            return (UIViewController *)responder;
    return nil;
}