IOS, XML截取成Json

//curString:服务返回xml, mName:方法名
//返回json字符串
-(NSString *)XmlToJson:(NSString *)curString MethodName:(NSString *)mName
{
    NSString *startnum;
    NSString *endnum;//尾部不好计算长度替换
   
    startnum= [NSString stringWithFormat:@"<ns:%@Response xmlns:ns=\"http://ws.apache.org/axis2\"><return>",mName];
    endnum= [NSString stringWithFormat:@"</return></ns:%@Response>",mName];
   
    NSMutableString *mstr;
    NSInteger int1=[startnum length];
    mstr=[NSMutableString stringWithString:curString]; //初始化可变字符串
    [mstr deleteCharactersInRange:NSMakeRange(0, int1)];//删除某个range的字符串
   
    NSRange substr;
    substr=[mstr rangeOfString:endnum];
    if (substr.location!=NSNotFound) {
        [mstr replaceCharactersInRange:substr withString:@""];
    }
    return  mstr;
}