Proxy 一般有2种协议，一种是 HTTP/HTTPS 协议，一种是 SOCKS 协议。优先使用 SOCKS 协议的 SOCKS5 版本。[2种协议的区别 待补充外部引用]
一般各平台的代理客户端除了提供一个本地的 socks5 Proxy ，还会提供一个本地的 http Proxy 。 在客户端相应设置中查看 socks5 协议监听的端口，HTTP Proxy 设置中查看 http 协议监听的端口。
注意：不少客户端提供混合模式，即
socks5和http端口号是同一个，所以不用费尽心思在软件设定中找单独的 http 端口设置功能了。
| MIT License | |
| Copyright (c) 2014 Piotr Kuczynski | |
| Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: | |
| The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. | |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWAR |
| static UIView *PSPDFViewWithSuffix(UIView *view, NSString *classNameSuffix) { | |
| if (!view || classNameSuffix.length == 0) return nil; | |
| UIView *theView = nil; | |
| for (__unsafe_unretained UIView *subview in view.subviews) { | |
| if ([NSStringFromClass(subview.class) hasSuffix:classNameSuffix]) { | |
| return subview; | |
| }else { | |
| if ((theView = PSPDFViewWithSuffix(subview, classNameSuffix))) break; | |
| } |
| - (BOOL)stringContainsEmoji:(NSString *)string { | |
| __block BOOL returnValue = NO; | |
| [string enumerateSubstringsInRange:NSMakeRange(0, [string length]) options:NSStringEnumerationByComposedCharacterSequences usingBlock: | |
| ^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) { | |
| const unichar hs = [substring characterAtIndex:0]; | |
| // surrogate pair | |
| if (0xd800 <= hs && hs <= 0xdbff) { | |
| if (substring.length > 1) { | |
| const unichar ls = [substring characterAtIndex:1]; |
