iOS NSData

1.与字典转换

NSDictionary *dic = @{@"name":@"macRong",@"webHome":@"eqi.cc"};

NSData *data =    [NSJSONSerialization dataWithJSONObject:dic options:NSJSONWritingPrettyPrinted error:nil];

NSDictionary *dictionary = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];

NSLog(@"NSDictionary 转 NSData = %@",data);

NSLog(@"NSData 转 NSDictionary =%@",dictionary);

2.与字符串转换

NSData* xmlData = [@"testdata" dataUsingEncoding:NSUTF8StringEncoding];

NSString *result = [[NSString alloc] initWithData:xmlData encoding:NSUTF8StringEncoding];

NSLog(@"NSString 转 NSData = %@",xmlData);

NSLog(@"NSData 转 NSString =%@",result);

3.//字典转json格式字符串

- (NSString *)dictionaryToJson:(NSDictionary *)dic

{

    NSError *parseError = nil;

    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dic options:NSJSONWritingPrettyPrinted error:&parseError];

    return [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];

}

- (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;

}