6.17 UIStoryboard
//获取someboard中InitialViewController
UIStoryboard *story = [UIStoryboard storyboardWithName:@"someboard" bundle:nil];
self.window.rootViewController = [story instantiateInitialViewController];
//获取someboard中identity为storyboardID的控制器
UIStoryboard *story = [UIStoryboard storyboardWithName:@"someboard" bundle:nil];
self.window.rootViewController = [story instantiateViewControllerWithIdentifier:@"storyboardID"];
6.18 UIResponder
- (BOOL)becomeFirstResponder; // 成为第一响应者(文本框获得焦点并调出键盘)
- (BOOL)resignFirstResponder; // 取消第一响应者(文本框失去焦点,隐藏键盘)