一些功能的实现思路

一、点击tabbar刷新数据

在UITabBarController中实现，遵循<UITabBarControllerDelegate>,实现代理方法

- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController

{

//_index记录点击的selectedIndex，开始的时候设置初始值为-1

if (_index == tabBarController.selectedIndex) {

//发送刷新的通知，userInfo传点击的selectedIndex，以便区分刷新的tabbar

[kNSNotificationCenter postNotificationName:kSelectTabBarRefresh object:nil userInfo:@{kTabBarSelectedIndex : @(_index)}];

}

_index = tabBarController.selectedIndex;

//1秒后重置初始值

dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{

_index = -1;

});

}

二、present 一个UIImagePickerController，导航栏遮挡（导航栏半透明状态）的解决方案

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated

{

viewController.navigationController.navigationBar.translucent = NO;

}

三、使用Apple提供的私有接口调式UI（二只手指同时点击状态栏）

SEL selector = NSSelectorFromString(@"prepareDebuggingOverlay");

[NSClassFromString(@"UIDebuggingInformationOverlay") performSelector:selector withObject:nil afterDelay:0];