三个男躁一个女,国精产品一区一手机的秘密,麦子交换系列最经典十句话,欧美 国产 综合 欧美 视频

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command+control+r

IOS Xcode中快捷鍵大全

在Xcode 中有許多快捷鍵的設(shè)定可以使得你的編程工作更為高效，對(duì)于在代碼文件中快速導(dǎo)航、定位Bug以及新增應(yīng)用特性都是極有效的。 當(dāng)然，你戳進(jìn)這篇文章的目的也在于想要快速的...

丿尛峯

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Using Custom Keys

In most cases, Cocoa-provided objects such as NSString objects should be sufficient for use as keys. In some cases, however, it may be necessary to use custom objects as keys in a dictionary. When using custom objects as keys, there are some important points to keep in mind.

Keys must conform to the NSCopying protocol. Methods that add entries to dictionaries—whether as part of initialization (for all dictionaries) or during modification (for mutable dictionaries)— don’t add each key object to the dictionary directly. Instead, they copy each key argument and add the copy to the dictionary. After being copied into the dictionary, the dictionary-owned copies of the keys should not be modified.

Keys must implement the hash and isEqual: methods because a dictionary uses a hash table to organize its storage and to quickly access contained objects. In addition, performance in a dictionary is heavily dependent on the hash function used. With a bad hash function, the decrease in performance can be severe. For more information on the hash and isEqual: methods see NSObject.

Important: Because the dictionary copies each key, keys must conform to the NSCopying protocol. Bear this in mind when choosing what objects to use as keys. Although you can use any object that adopts the NSCopying protocol and implements the hash and isEqual: methods, it is typically bad design to use large objects, such as instances of NSImage, because doing so may incur performance penalties.
感覺(jué)這里解釋得更清楚啊。

roylly 評(píng)論自iOS使用自定義對(duì)象作為NSDictionary的key探索

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CAEAGLLayer是iOS5之后提供的完成OpenGL繪圖緩沖的底層配置的

清水_yuxin 評(píng)論自CALayer-緒論（iOS論文系列）

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@會(huì)飛的櫻桃_300e 沒(méi)毛病 遍歷只是開放定址法

iOS管理對(duì)象內(nèi)存的數(shù)據(jù)結(jié)構(gòu)以及操作算法--SideTables、RefcountMap、weak_table_t-一

第一次寫文章語(yǔ)言表達(dá)能力太差。如果有哪里表達(dá)的不夠清晰可以直接評(píng)論回復(fù)我,我來(lái)加以修改。這篇文章力求脫離語(yǔ)言的特性，咱們多講結(jié)構(gòu)和算法。即使你不懂iOS開發(fā)，不懂Object...

iOS入門級(jí)攻城尸

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return (i+1) & mask;

iOS實(shí)例方法cache_t的緩存邏輯

先放一份流程圖： 一、試驗(yàn)： 我們先做個(gè)試驗(yàn)： 執(zhí)行三個(gè)方法 代碼： 然后打印出類里面的cache 其中_mask是緩存池的最大容量_occupied是緩存池緩存的方法數(shù)量 ...

海浪萌物

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