iphone的一点入门文章

http://blog.codingmylife.com/?p=23 今天在尝试抓取起点中文网首页的时候遇到了一个问题 — 如果编码没有用对的话是没办法读取任何东西的. 这也算是C#用的太多养成的坏习惯, 以前基本没怎么考虑过编码问题. 应该说, C#里面就算编码错了, 也能读进来东西, 只是一片乱码而已. Cocoa里面就狠了点, 直接抛异常了. 下面是刚开始写的一段代码, 把起点中文网的主页下载到一个字符串中. 1 2 3 4 5 6 7 8 9 10 11 12 NSURL *url = [[NSURL alloc] initWithString:@"http://www.cmfu.com"]; NSError *error; NSString *xml = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error]; if(xml == nil) { NSLog(@"Error reading url at %@", [error localizedFailureReason]); } else { [result setString:xml]; } 死活下载失败, 错误信息就是编码不对. 好吧, 我打开了帮助查看了下所有的编码: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 enum { NSASCIIStringEncoding = 1, NSNEXTSTEPStringEncoding = 2, NSJapaneseEUCStringEncoding = 3, NSUTF8StringEncoding = 4, NSISOLatin1StringEncoding = 5, NSSymbolStringEncoding = 6, NSNonLossyASCIIStringEncoding = 7, NSShiftJISStringEncoding = 8, NSISOLatin2StringEncoding = 9, NSUnicodeStringEncoding = 10, NSWindowsCP1251StringEncoding = 11, NSWindowsCP1252StringEncoding = 12, NSWindowsCP1253StringEncoding = 13, NSWindowsCP1254StringEncoding = 14, NSWindowsCP1250StringEncoding = 15, NSISO2022JPStringEncoding = 21, NSMacOSRomanStringEncoding = 30, NSProprietaryStringEncoding = 65536 }; 我一个一个的试, 居然全都不行! 崩溃了, 这都什么年代了, 难道Cocoa还不支持中文? 不可能啊. 估计是上面那份文档里面只是列出了最长用的几种编码(这里是苹果认为最长用的, 可见对于中国基本是无视了, 鄙视下!), 我就写了下面这段代码输出了所有支持的编码: 1 2 3 4 5 6 7 8 9 const NSStringEncoding *encodings = [NSString availableStringEncodings]; NSMutableString *str = [[NSMutableString alloc] init]; NSStringEncoding encoding; while ((encoding = *encodings++) != 0) { [str appendFormat: @"%@ === %in", [NSString localizedNameOfStringEncoding:encoding], encoding]; } [result setString: str]; 好家伙, 果然被我猜中了, 下面就是所有支持的编码列表 Western (Mac OS Roman) === 30 Japanese (Mac OS) === -2147483647 Traditional Chinese (Mac OS) === -2147483646 Korean (Mac OS) === -2147483645 Arabic (Mac OS) === -2147483644 Hebrew (Mac OS) === -2147483643 Greek (Mac OS) === -2147483642 Cyrillic (Mac OS) === -2147483641 Devanagari (Mac OS) === -2147483639 Gurmukhi (Mac OS) === -2147483638 Gujarati (Mac OS) === -2147483637 Thai (Mac OS) === -2147483627 Simplified Chinese (Mac OS) === -2147483623 Tibetan (Mac OS) === -2147483622 Central European (Mac OS) === -2147483619 Symbol (Mac OS) === 6 Dingbats (Mac OS) === -2147483614 Turkish (Mac OS) === -2147483613 Croatian (Mac OS) === -2147483612 Icelandic (Mac OS) === -2147483611 Romanian (Mac OS) === -2147483610 Celtic (Mac OS) === -2147483609 Gaelic (Mac OS) === -2147483608 Keyboard Symbols (Mac OS) === -2147483607 Farsi (Mac OS) === -2147483508 Cyrillic (Mac OS Ukrainian) === -2147483496 Inuit (Mac OS) === -2147483412 Unicode (UTF-32LE) === -1677721344 Unicode (UTF-8) === 4 Unicode (UTF-16) === 10 Unicode (UTF-16BE) === -1879047936 Unicode (UTF-16LE) === -1811939072 Unicode (UTF-32) === -1946156800 Unicode (UTF-32BE) === -1744830208 Western (ISO Latin 1) === 5 Central European (ISO Latin 2) === 9 Western (ISO Latin 3) === -2147483133 Central European (ISO Latin 4) === -2147483132 Cyrillic (ISO 8859-5) === -2147483131 Arabic (ISO 8859-6) === -2147483130 Greek (ISO 8859-7) === -2147483129 Hebrew (ISO 8859-8) === -2147483128 Turkish (ISO Latin 5) === -2147483127 Nordic (ISO Latin 6) === -2147483126 Thai (ISO 8859-11) === -2147483125 Baltic Rim (ISO Latin 7) === -2147483123 Celtic (ISO Latin === -2147483122 Western (ISO Latin 9) === -2147483121 Romanian (ISO Latin 10) === -2147483120 Latin-US (DOS) === -2147482624 Greek (DOS) === -2147482619 Baltic Rim (DOS) === -2147482618 Western (DOS Latin 1) === -2147482608 Greek (DOS Greek 1) === -2147482607 Central European (DOS Latin 2) === -2147482606 Cyrillic (DOS) === -2147482605 Turkish (DOS) === -2147482604 Portuguese (DOS) === -2147482603 Icelandic (DOS) === -2147482602 Hebrew (DOS) === -2147482601 Canadian French (DOS) === -2147482600 Arabic (DOS) === -2147482599 Nordic (DOS) === -2147482598 Cyrillic (DOS) === -2147482597 Greek (DOS Greek 2) === -2147482596 Thai (Windows, DOS) === -2147482595 Japanese (Windows, DOS) === 8 Simplified Chinese (Windows, DOS) === -2147482591 Korean (Windows, DOS) === -2147482590 Traditional Chinese (Windows, DOS) === -2147482589 Western (Windows Latin 1) === 12 Central European (Windows Latin 2) === 15 Cyrillic (Windows) === 11 Greek (Windows) === 13 Turkish (Windows Latin 5) === 14 Hebrew (Windows) === -2147482363 Arabic (Windows) === -2147482362 Baltic Rim (Windows) === -2147482361 Vietnamese (Windows) === -2147482360 Western (ASCII) === 1 Japanese (Shift JIS X0213) === -2147482072 Chinese (GBK) === -2147482063 Chinese (GB 18030) === -2147482062 Japanese (ISO 2022-JP) === 21 Korean (ISO 2022-KR) === -2147481536 Japanese (EUC) === 3 Simplified Chinese (EUC) === -2147481296 Traditional Chinese (EUC) === -2147481295 Korean (EUC) === -2147481280 Japanese (Shift JIS) === -2147481087 Cyrillic (KOI8-R) === -2147481086 Traditional Chinese (Big 5) === -2147481085 Western (Mac Mail) === -2147481084 Simplified Chinese (HZ GB 2312) === -2147481083 Traditional Chinese (Big 5 HKSCS) === -2147481082 Ukrainian (KOI8-U) === -2147481080 Traditional Chinese (Big 5-E) === -2147481079 Western (NextStep) === 2 Non-lossy ASCII === 7 Western (EBCDIC Latin 1) === -2147480574 终于看到了熟悉的 GBK 编码, 对应的代码是 -2147482063. Ok, 更改一下最开始的代码 1 2 3 4 5 6 7 8 9 10 11 12 13 NSURL *url = [[NSURL alloc] initWithString:@"http://www.cmfu.com"]; NSError *error; NSStringEncoding encoder; NSString *xml = [NSString stringWithContentsOfURL:url encoding:encoder=-2147482063 error:&error]; if(xml == nil) { NSLog(@"Error reading url at %@", [error localizedFailureReason]); } else { [result setString:xml]; } 终于搞定了! 看到熟悉的中文真是激动了. posted under Cocoa One Comment to “读取任意编码的文件.” On August 21st, 2007 at 10:05 am Glider Says: 如果用CoreFoundation的Framework似乎就没有那么复杂了，直接用CFStringCreateWithBytes()，参数带kCFStringEncodgingGB180302000就可以了。 Name: Email: Email will not be published Website Address: Website example Your Comment: