iOS development--Encoding format

1.url encoding

When HTTP requests in iOS encounter Chinese characters, they need to be converted to UTF-8, using the following methods:

NSString * encodingstring = [urlstring stringbyaddingpercentescapesusingencoding:nsutf8stringencoding];

The result is%3a%2f%2f;

2.url decoding Chinese

After the request, the returned data, if shown is the format:%3a%2f%2f, this time we need to do UTF-8 decoding, the method used is:

NSString *str = [Model.album_name stringbyreplacingpercentescapesusingencoding:nsutf8stringencoding];

UTF-8 Turn GBK

The result is Chinese

3.Unicode encoding and conversion of Chinese characters

This code is typically used for network programming. The data obtained from the server is typically a Unicode format string that needs to be converted to Chinese encoding correctly.

NSString a string encoding (such as \u7e8c) in Unicode format converted to Chinese

Unicode encoding starts with \u

+ (NSString *) Replaceunicode: (NSString *) unicodestr

{

NSString *TEMPSTR1 = [unicodestrstringbyreplacingoccurrencesofstring:@ "\\u" withstring:@ "\\u"];

NSString *TEMPSTR2 = [tempstr1stringbyreplacingoccurrencesofstring:@ "" "withstring:@" \ ""];

NSString *TEMPSTR3 = [[@ "" "" Stringbyappendingstring:tempstr2] stringbyappendingstring:@ "" "];

NSData *tempdata = [tempstr3datausingencoding:nsutf8stringencoding];

nsstring* returnstr = [Nspropertylistserializationpropertylistfromdata:tempdata

Mutabilityoption:nspropertylistimmutable

Format:null

Errordescription:null];

NSLog (@ "%@", returnstr);

return [returnstrstringbyreplacingoccurrencesofstring:@ "\\r\\n" withstring:@ "\ n"];

}

\u6211\u662f\u4e2d\u6587\u5b57\u7b26
\uxxxx This format is a Unicode notation that represents a character in which XXXX represents a 16-digit, range-0~65535. Unicode hexadecimal numbers can only contain numeric 0~9, uppercase letters A~F, or lowercase a~f. It is important to note that the size-to-end problem of Unicode, which is usually small-ended, such as \u5c0f, which represents the ' small ' word in Chinese, is converted to 10 binary is 9215, so the byte array should be 1592.

Kanji to Unicode

Privatestring Unicode2chinese (String strunicode) {string[] splitstring=NewString[1]; splitstring[0] = "\\u"; String[] Unicodearray=strunicode.split (splitstring, stringsplitoptions.removeemptyentries); StringBuilder SB=NewStringBuilder (); foreach (string item in Unicodearray) {byte[] codes =New byte[2]; intCode1, Code2; Code1= Convert.ToInt32 (item. Substring (0, 2), 16); Code2= Convert.ToInt32 (item. Substring (2), 16); codes[0] = (byte) Code2;//must be small end in frontCODES[1] = (byte) Code1; Sb.    Append (Encoding.Unicode.GetString (codes)); }    returnsb. ToString ();}

Unicode to Kanji

Private string Chinese2unicode (String Strchinese) {    = string. Empty;    foreach (char  item in Strchinese.tochararray ())    {        + = "\\u" + (int//  16 binary     }    return  strunicodes;}

iOS development--Encoding format