【iOS开发】字典(NSDictionary)和JSON字符串(NSString)之间互转

1. 字典转Json字符串

+ (NSString*)convertToJSONData:(id)infoDict
{
    NSError *error;
    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:infoDict
                                                       options:NSJSONWritingPrettyPrinted // Pass 0 if you don't care about the readability of the generated string
                                                         error:&error];

    NSString *jsonString = @"";

    if (! jsonData) 
    {
        NSLog(@"Got an error: %@", error);
    }else
    {
        jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
    }

    jsonString = [jsonString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];  //去除掉首尾的空白字符和换行字符

    [jsonString stringByReplacingOccurrencesOfString:@"\n" withString:@""];

    return jsonString;
}

2. JSON字符串转化为字典

+ (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;
}