| 共 13 篇文章 |
|
anonymous object （匿名对象） 未知类的一个对象。A memory-management technique in which each entity that claims ownership of an object increments the object’s reference count and later decrements it. When the object’s reference count reaches zero, the object is deallocated. This technique allows one instance of an ob... 阅69 转1 评0 公众公开 15-10-20 16:01 |
Objective-C 编程语言官网文档（十二）-线程声明:本文档仅为个人学习过程中顺手翻译之作，方便开发的同胞借鉴参考。@synchronized() 指令只有一个参数，可以是任何 Objective-C 对象, 包括 self. 这个对象被称为互斥信号量. 它允许一个线程锁定一个代码块以防止同一时间被其它线程访问。To protect sections of code from being executed by mo... 阅60 转1 评0 公众公开 15-10-20 16:01 |
可以使用 @throw 指令来抛出一个异常，本质上来说这是一个 Objective-C 对象. 通常你会用到一个 NSException 对象，但不是必须的。@catch (NSException *exception) {没人限制你必须抛出 NSException 对象. 你可以抛出任何 Objective-C 的对象来作为异常对象. NSException 类提供了可以在异常处理提供帮助的方法，但如果愿意你可以实现你自己... 阅41 转1 评0 公众公开 15-10-20 16:00 |
The runtime system makes sure each identifier is unique: No two selectors are the same, and all methods with the same name have the same selector.The display method for one class, for example, has the same selector as display methods defined in other classes.The messaging routine has access to method implementations o... 阅170 转1 评0 公众公开 15-10-20 16:00 |
Static typing also doesn’t affect how the object is treated at runtime. Statically typed objects are dynamically allocated by the same class methods that create instances of type id. If Square is a subclass of Rectangle, the following code would still produce an object with all the instance variables of a Square obje... 阅58 转1 评0 公众公开 15-10-20 16:00 |
NSArray *array = <#Get an array#>;The following code example illustrates using fast enumeration with NSArray and NSDictionary objects.For collections or enumerators that have a well-defined order—such as an NSArray or an NSEnumerator instance derived from an array—the enumeration proceeds in that order, so sim... 阅51 转1 评0 公众公开 15-10-20 15:59 |
(NSString *)objc_getAssociatedObject(array, &overviewKey);objc_setAssociatedObject(array, &overviewKey, nil, OBJC_ASSOCIATION_ASSIGN);You use the Objective-C runtime function objc_setAssociatedObject to make an association between one object and another.At point 1, the string overview is still valid because th... 阅46 转1 评0 公众公开 15-10-20 15:59 |
The declaration of a category interface looks very much like a class interface declaration—except the category name is listed within parentheses after the class name and the superclass isn’t mentioned. Unless its methods don’t access any instance variables of the class, the category must import the interface file f... 阅54 转1 评0 公众公开 15-10-20 15:58 |
属性(Property)声明中的额外属性（Attribute）Property跟Attribute都可翻译为属性，但两者在这里是不同的，Property只类范围的属性，而Attributes是额外属性，作用域比Property小。Important If you do not specify either @synthesize or @dynamic for a particular property, you must provide a getter and setter (or just a getter in the... 阅73 转1 评0 公众公开 15-10-20 15:57 |
Declaring a Protocol.They both declare methods, and at runtime they’re both represented by objects—classes by instances of Class and protocols by instances of Protocol. Like class objects, protocol objects are created automatically from the definitions and declarations found in source code and are used by the runtim... 阅113 转1 评0 公众公开 15-10-20 15:56 |
