1.如何获取当前最上层的UIViewController?
请看代码分析：
//获取当前最上层的控制器
-(UIViewController *) getTopMostController
{
UIWindow *topWindow = [UIApplication sharedApplication].keyWindow;
if (topWindow.windowLevel != UIWindowLevelNormal)
{
topWindow = [self returnWindowWithWindowLevelNormal];
}
UIViewController *topController = topWindow.rootViewController;
if(topController == nil)
{
topWindow = [UIApplication sharedApplication].delegate.window;
if (topWindow.windowLevel != UIWindowLevelNormal)
{
topWindow = [self returnWindowWithWindowLevelNormal];
}
topController = topWindow.rootViewController;
}
while(topController.presentedViewController)
{
topController = topController.presentedViewController;
}
if([topController isKindOfClass:[UINavigationController class]])
{
UINavigationController *nav = (UINavigationController*)topController;
topController = [nav.viewControllers lastObject];
while(topController.presentedViewController)
{
topController = topController.presentedViewController;
}
}
return topController;
}
// 获取目标window
-(UIWindow *) returnWindowWithWindowLevelNormal
{
NSArray *windows = [UIApplication sharedApplication].windows;
for(UIWindow *topWindow in windows)
{
if (topWindow.windowLevel == UIWindowLevelNormal)
return topWindow;
}
return [UIApplication sharedApplication].keyWindow;
}
先获取目标window，然后获取目标window的rootViewController，然后获取rootViewController的presentedViewController，并判断其是否是UINavigationController的子类，若不是那就取其本身，如果是那么久通过其viewControllers属性访问它lastObject来获取最上层ViewController。
