iOS 字典 字符串和二进制的相互转换

二进制转化为字符串

NSString *jsonStr = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

二进制数据转成字典

NSData *jsonData ；
NSDictionary *dicJson=[NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers error:nil];

把字符串再转变为二进制流

NSData *data=[NSMutableData dataWithData:[str dataUsingEncoding:NSUTF8StringEncoding]];

字典转成二进制数据

NSError *parseError = nil;

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

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];  
}

json格式字符串转字典

- (NSDictionary *)dictionaryWithJsonString:(NSString *)jsonString {

    if (jsonString == nil) {

        return nil;

    }

    NSData *jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];

    NSError *err;

    NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:jsonData

                                                        options:NSJSONReadingMutableContainers

                                                          error:&err];

    if(err) {

        NSLog(@"json解析失败：%@",err);

        return nil;

    }

    return dic;

}