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搜索关键字:optional chaining    ( 1219个结果
Core Data数据库迁移
一、 Lightweight Migrationi. 适合场景Simple addition of a new attributeRemoval of an attributeA non-optional attribute becoming optionalAn optional attribut...
分类:数据库   时间:2015-06-25 13:59:05    阅读次数:132
UIApplicationDelegate协议
//网络引用@protocol UIApplicationDelegate@optional//常用的:- (void)applicationDidFinishLaunching:(UIApplication *)application;//当程序完成载入后调用- (BOOL)application...
分类:移动开发   时间:2015-06-24 12:22:01    阅读次数:125
swift optional chaining
class ca{    var num:Int =1; } class cb{    var a:ca?; } class cc{    var b:cb?; } var x:cc =cc(); var y:Int? =x.b?.a?.num;//或var y = x.b?.a?.num; println("y =\(y),\r\...
分类:编程语言   时间:2015-06-21 13:14:01    阅读次数:163
Android如何编程设置APP安装位置(外部存储或内部存储)?
Beginning with API Level 8, you can allow your application to be installed on the external storage (for example, the device's SD card). This is an optional feature you can declare for your applica...
分类:移动开发   时间:2015-06-17 16:47:41    阅读次数:145
tomcat+apr
Documentation IndexIntroductionThe Apache Tomcat Native Library is an optional component for use with Apache Tomcat that allows Tomcat to use certain ...
分类:其他好文   时间:2015-06-16 16:28:36    阅读次数:103
< Objective-C >协议,反射和类别
协议(@protocol):相当于java的接口协议的方法不一定要实现,可以使用@required和@optional来设置,默认为@required(ob为弱语法,即使不实现必选方法编译运行也不会报错)Class的反射常用方法Class 变量名 = [类或者对象 class];Class 变量名 ...
分类:其他好文   时间:2015-06-16 10:41:49    阅读次数:105
Swift之旅:1.概述-用Swift实现一个简单的计算器
Swift语言初探,autoLayout初探,实现一个简单的计算器...
分类:编程语言   时间:2015-06-14 10:58:23    阅读次数:212
OC Protocol----协议
类似Java的泛型与接口的结合体,用于类型的中,可以多继承(按照OC的说法叫遵从某些协议)1、定义协议@protocol Client -(void)defaultMethod;//默认必须实现 @required//必须 -(void)required; @optional//可...
分类:其他好文   时间:2015-06-11 18:34:32    阅读次数:112
fopen 模拟 post 提交
function?do_post_request($url,?$data,?$optional_headers?=?null){ ????????$params?=?array(‘http‘?=>?array( ????????????‘method‘?=>?‘POST‘, ????????????‘co...
分类:其他好文   时间:2015-06-11 09:39:54    阅读次数:108
baksmali反编译出现:UNEXPECTED TOP-LEVEL ERROR:....Too many open files
解包大型apk文件,可能会出现如下错误, UNEXPECTED TOP-LEVEL ERROR: java.util.concurrent.ExecutionException: java.io.FileNotFoundException/./Contacts/com/google/common/base/Optional$1.smali (Too many open files)     ...
分类:其他好文   时间:2015-06-10 17:19:29    阅读次数:138
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