可拿到当前控制器（ControllerView，NavgationController）等。
- (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;
}
