Objective-c NSString 转utf-8和gb2312

#pragma mark -#pragma mark Encode Chinese to ISO8859-1 in URL-(NSString *)EncodeUTF8Str:(NSString *)encodeStr{CFStringRef nonAlphaNumValidChars = CFSTR("![        DISCUZ_CODE_1        ]’()*+,-./:;=?@_~");        NSString *preprocessedString = (NSString *)CFURLCreateStringByReplacingPercentEscapesUsingEncoding(kCFAllocatorDefault, (CFStringRef)encodeStr, CFSTR(""), kCFStringEncodingUTF8);        NSString *newStr = [(NSString *)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,(CFStringRef)preprocessedString,NULL,nonAlphaNumValidChars,kCFStringEncodingUTF8) autorelease];[preprocessedString release];return newStr;        }#pragma mark -#pragma mark Encode Chinese to GB2312 in URL-(NSString *)EncodeGB2312Str:(NSString *)encodeStr{CFStringRef nonAlphaNumValidChars = CFSTR("![        DISCUZ_CODE_1        ]’()*+,-./:;=?@_~");        NSString *preprocessedString = (NSString *)CFURLCreateStringByReplacingPercentEscapesUsingEncoding(kCFAllocatorDefault, (CFStringRef)encodeStr, CFSTR(""), kCFStringEncodingGB_18030_2000);        NSString *newStr = [(NSString *)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,(CFStringRef)preprocessedString,NULL,nonAlphaNumValidChars,kCFStringEncodingGB_18030_2000) autorelease];[preprocessedString release];return newStr;        }