10.5.8. ios收集¶

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:
```
nonatomic
copy
weak/strong
```

收集:

the _name, _location, and _date symbols refer to the instance variables that these properties represent
the accessor methods—such as self.name;
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_async的意思就是将任务进行异步并行处理
dispatch_group_async

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
//还有两个:DISPATCH_QUEUE_PRIORITY_HIGH, DISPATCH_QUEUE_PRIORITY_LOW

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:

//应用跳转到AppStore指定关键字(呵呵)搜索界面
NSString *str = [NSString stringWithFormat:
    @"https://itunes.apple.com/WebObjects/MZStore.woa/wa/search?mt=8&submit=edit&term=%@#software",
    [@"呵呵" stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding] ];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:str]];
// 跳转到下载界面
NSString *str = [NSString stringWithFormat:
    @"itms-apps://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=%d",
    909480609 ];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:str]];

//根据分类搜索界面
// NSString *stringURL = @"https://itunes.apple.com/cn/genre/ios-zhi-bo/id6007?mt=8";
//https://itunes.apple.com/cn/artist/xiamen-meitu-technology-co./id416048308
// https://itunes.apple.com/cn/artist/xiamen-meitu-technology-co./id416048308#
NSString *stringURL = @"https://itunes.apple.com/cn/genre/ios-jiao-yu/id6017?mt=8";

NSURL *url = [NSURL URLWithString:stringURL];
[[UIApplication sharedApplication] openURL:url];