• storyboard中三个标识:

    an orange cube that represents the first responder
    a yellow sphere that represents the scene’s view controller objct
    a green square that represents the destination of an unwind segue.
  • 常用的菜单:

    Editor > Embed In > Navigation Controller
  • property的几个实例:

  • 收集:

    the _name, _location, and _date symbols refer to the instance variables that these properties represent
    the accessor methods—such as;
    By convention, the underscore serves as a reminder that you shouldn’t access instance variables directly.
    The only two places where you should not use accessor methods are in init methods—such as initWithName—and in dealloc methods.
    a mutable array, which is an array that can grow.
    the copy attribute in (nonatomic, copy): It specifies that a copy of the object should be used for assignment.
    A class extension allows you to declare a method that is private to the class
  • 方法:

    dispatch_get_main_queue() 函数就是返回主线程
    dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0) 得到系统队列
  • 说明:

    Grand Central Dispatch或者GCD,是一套低层API,提供了一种新的方法来进行并发程序编写。
  • 应用跳转到AppStore指定关键字搜索界面:

    NSString *str = [NSString stringWithFormat:
        [@"呵呵" stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding] ];
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:str]];
    // 跳转到下载界面
    NSString *str = [NSString stringWithFormat:
        909480609 ];
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:str]];
    // NSString *stringURL = @"";
    NSString *stringURL = @"";
    NSURL *url = [NSURL URLWithString:stringURL];
    [[UIApplication sharedApplication] openURL:url];