NSString encoding and conversion

There are often many encoding methods, and the conversion methods between lists

NSString To UFT-8

[Cpp]
NSString * str2 = @ "deep ";
Const char * s = [str2 UTF8String];
The following format is displayed: \ U6df1 \ U5733 \ U56fd \ U5f00 \ U884c01 \ U673a \ U623. The conversion test function is a Unicode code.

[Cpp]
-(NSString *) replaceUnicode :( NSString *) unicodeStr {
NSString * tempStr1 = [unicodeStr stringByReplacingOccurrencesOfString: @ "\ u" withString: @ "\ U"];
NSString * tempStr2 = [tempStr1 stringByReplacingOccurrencesOfString: @ "\" "withString: @" \ ""];
NSString * tempStr3 = [[@ "\" "stringByAppendingString: tempStr2] stringByAppendingString: @" \ ""];
NSData * tempData = [tempStr3 dataUsingEncoding: NSUTF8StringEncoding];
NSString * returnStr = [NSPropertyListSerialization propertyListFromData: tempData
MutabilityOption: NSPropertyListImmutable
Format: NULL
ErrorDescription: NULL];

Return [returnStr stringByReplacingOccurrencesOfString: @ "\ r \ n" withString: @ "\ n"];
}
The following fields are displayed: & # x6DF1; & # x5733; & # x94F6; & # x884C; ", which is usually a GBK code. The conversion method is
[Cpp]
NSURL * url = [NSURL URLWithString: str2];
NSData * responseData = [NSData dataWithContentsOfURL: url];
NSStringEncoding enc = CFStringConvertEncodingToNSStringEncoding (kCFStringEncodingGB_18030_2000 );
NSString * responseString = [[NSString alloc] initWithData: responseData encoding: enc];