iOS 获取当前展示的页面

- (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;
}

 

- (UIViewController *)getPresentedViewController
{
    UIViewController *appRootVC = [UIApplication sharedApplication].keyWindow.rootViewController;
    UIViewController *topVC = appRootVC;
    if (topVC.presentedViewController) {
        topVC = topVC.presentedViewController;
    }

    return topVC;
}

如果是在AppDelegate中
如果是用UINavigationController来组织页面结构的话可以使用：
((UINavigationController*)appDelegate.window.rootViewController).visibleViewController;
如果是用UITabBarController来组织页面结构的话：
((UITabBarController*)appDelegate.window.rootViewController).selectedViewController;