iOS NSDictionary NSString互转

-(NSString *)convertToJsonData:(NSDictionary *)dict
{
    NSError *error;
    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dict options:NSJSONWritingPrettyPrinted error:&error];
    NSString *jsonString;
    
    if (!jsonData) {
        NSLog(@"%@",error);
    }else{
        jsonString = [[NSString alloc]initWithData:jsonData encoding:NSUTF8StringEncoding];
    }
    
    NSMutableString *mutStr = [NSMutableString stringWithString:jsonString];
    //    NSRange range = {0,jsonString.length};
    //    //去掉字符串中的空格
    //    [mutStr replaceOccurrencesOfString:@" " withString:@"" options:NSLiteralSearch range:range];
    NSRange range2 = {0,mutStr.length};
    //去掉字符串中的换行符
    [mutStr replaceOccurrencesOfString:@"\n" withString:@"" options:NSLiteralSearch range:range2];
    
    return mutStr;
}

-(NSDictionary *)convertToDictionary:(NSString *)jsonStr
{
    NSData *data = [jsonStr dataUsingEncoding:NSUTF8StringEncoding];
    NSDictionary *tempDic = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
    
    return tempDic;
}