每行 C# CSV 到 JSON

Question

主要编辑：我在解释方面做得不好:(

我有两个班级：

public class UserDefinitions// a list of 'Items', each'group of items belong to a user. I handle User logic elsewhere, and it works flawlessly.  
    {
        public List<Item> items { get; set; }
    }
public class Item //the User definitions. A user could have 1 or 15 of these. They would all be a single 'line' from the CSV file.
    {

       public string definitionKey { get; set; }
       public string defName { get; set; }
       public string defValue { get; set; }

    }

我想用 CSV 文件构建。我构建了这个 CSV 文件，所以我每次都使用相同的参数。

我在公司的数据库上运行 SQL 以生成如下结果：http://i.imgur.com/gS1UJot.png

然后我像这样读取文件：

class Program
{
    static void Main(string[] args)
    {
        var userData = new UserDefinitions();
        var csvList = new List<Item>();
        string json = "";
        string fPath = @"C:\test\csvTest.csv";
        var lines = File.ReadAllLines(fPath);
        Console.WriteLine(lines);
        List<string> udata = new List<string>(lines);
        foreach (var line in udata)
        {
            string[] userDataComplete = line.Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries);// this cleans any empty cells from the CSV  

            csvList.Add(new Item { definitionKey = userDataComplete[1], defName = userDataComplete[2], defValue = userDataComplete[3] });
        }

        json = JsonConvert.SerializeObject(csvList); //everything below is for debugging/tracking progress  
        Console.WriteLine(json);
        Console.ReadKey();

        StreamWriter sw = new StreamWriter("C:\\test\\testjson.txt");
        sw.WriteLine(json);
        sw.Close();

     }

  }

这几乎可以满足我的要求。输出 json 来自 csv 数据的第一个“列”

[{"definitionKey":"uuid1","defName":"HairColor","defValue":"Brown"},{"definitionKey":"uuid1","defName":"HairColor","defValue" :"Blonde"},{"definitionKey":"uuid1","defName":"HairColor","defValue":"Blue"}]

以屏幕截图为例，wanted输出应该是

[{"attributeDefinitionKey":"uuid1","name":"HairColor","value":"Brown"},{"definitionKey":"uuid2","defName":"FreckleAmount","defValue" :"50"}] [{"attributeDefinitionKey":"uuid1","name":"HairColor","value":"Blonde"},{"definitionKey":"uuid2","defName":"FreckleAmount","defValue":"null "}] [{"attributeDefinitionKey":"uuid1","name":"HairColor","value":"Blue"},{"definitionKey":"uuid3","defName":"Tattoos","defValue":"5 "}]

我不能随意挑选某些方面，或将它们应用于项目。例如，可能有 10 个用户或 5000 个用户，但定义密钥将始终为 [1]，添加 '3' 将获得每个后续定义密钥。就像 defName 将始终在 [2] 位置，添加 3 将获得每个后续的 defName（如果有的话），这都是每行。

我知道我必须添加一些 +3 逻辑，但不太确定如何合并它。也许是一个for循环？ foreach 循环之后的嵌套 for 循环？我觉得我错过了一些明显的东西！

再次感谢您的帮助

Answer 1

这会逐行读取 csv 行并将每一行转换为 json，同时适应列数的变化。

这仅在 CSV 遵循您的规则时才有效：
一个用户 ID 和
x 数量的“事物”，每个“事物”有 3 列。

private static void Main(string[] args)
    {
        var file = new StreamReader(@"C:\test\csvTest.csv");
        string line;
        var itemsJson = new List<string>();
        file.ReadLine();
        while ((line = file.ReadLine()) != null)
        {
            var sb = new StringBuilder();
            var fields = line.Split(',');


            sb.Append(GetKeyValueJson("UserId", fields[0]));
            for (var i = 1; i < fields.Length; i += 3)
            {
                var x = (i + 3) / 3;
                sb.Append(GetKeyValueJson($"Thing {i + x} ID", fields[i]));
                sb.Append(GetKeyValueJson($"Thing {i + x} ID", fields[i + 1]));


                sb.Append(i + 3 == fields.Length
                    ? GetKeyValueJson($"Thing {i + x} ID", fields[i + 2], true)
                    : GetKeyValueJson($"Thing {i + x} ID", fields[i + 2]));
            }

            itemsJson.Add(WrapJson(sb.ToString()));
        }

        var json = WrapItems(itemsJson);


        Console.ReadLine();
    }

    private static string GetKeyValueJson(string id, string value, bool lastPair = false)
    {
        var sb = new StringBuilder();
        sb.Append('"');
        sb.Append(id);
        sb.Append('"');
        sb.Append(':');
        sb.Append('"');
        sb.Append(value);
        sb.Append('"');
        if (!lastPair)
            sb.Append(',');

        return sb.ToString();
    }

    private static string WrapJson(string s)
    {
        var sb = new StringBuilder();
        sb.Append('{');
        sb.Append(s);
        sb.Append('}');

        return sb.ToString();
    }

    private static string WrapItems(List<string> jsonList)
    {
        var sb = new StringBuilder();
        sb.Append('"');
        sb.Append("Items");
        sb.Append('"');
        sb.Append(':');
        sb.Append('[');
        sb.Append(jsonList.Aggregate((current, next) => current + "," + next));
        sb.Append(']');

        return WrapJson(sb.ToString());
    }
}

它不是很漂亮，排序会很困难，但它应该适应列的数量，只要它是 3 的。