Writing nested collection to datatable c#

Question

Basically I have a class like this:

public class A
{
    public A()
    {
    }

    public Guid Key { get; set; }

    public long PrimaryId { get; set; }

    public bool IsActive { get; set; }

    public Dictionary<string, string> Dict { get; set; }

    public Dictionary<int, string> Dict1 { get; set; }
}

Based on the answer here, I can use TypeDescriptor which works great for non-nested collections. For nested collections and dictionary I use a method like this:

    private static bool IsEnumerable(PropertyInfo pi)
    {
        // note: we could also use IEnumerable (but string, arrays are IEnumerable...)
        return typeof(ICollection).IsAssignableFrom(pi.PropertyType);
    }

    private static bool IsDictionary(PropertyInfo pi)
    {
        return pi.PropertyType.IsGenericType && pi.PropertyType.GetGenericTypeDefinition() == typeof(Dictionary<,>);
    }

However, if someone can help with a method which converts a generic list to DataTable. That will be great.

Does this answer your question? [Convert generic List/Enumerable to DataTable?](https://stackoverflow.com/questions/564366/convert-generic-list-enumerable-to-datatable) — Vivek Nuna, Jun 16 '20 at 08:23
@viveknuna: i am using the same answer but my list contains a nested collection or dictionary — Gauravsa, Jun 16 '20 at 08:31

score 0 · Answer 1 · answered Jun 16 '20 at 10:24

Check this Coverting List of Dictionary to DataTable

static DataTable ToDataTable(List<Dictionary<string, int>> list)
{
    DataTable result = new DataTable();
    if (list.Count == 0)
        return result;

    var columnNames = list.SelectMany(dict=>dict.Keys).Distinct();
    result.Columns.AddRange(columnNames.Select(c=>new DataColumn(c)).ToArray());
    foreach (Dictionary<string,int> item in list)
    {
        var row = result.NewRow();
        foreach (var key in item.Keys)
        {
            row[key] = item[key];
        }

        result.Rows.Add(row);
    }

    return result;
}

static void Main(string[] args)
{
    List<Dictionary<string, int>> it = new List<Dictionary<string, int>>();
    Dictionary<string, int> dict = new Dictionary<string, int>();
    dict.Add("a", 1);
    dict.Add("b", 2);
    dict.Add("c", 3);
    it.Add(dict);
    dict = new Dictionary<string, int>();
    dict.Add("bob", 34);
    dict.Add("tom", 37);
    it.Add(dict);
    dict = new Dictionary<string, int>();
    dict.Add("Yip Yip", 8);
    dict.Add("Yap Yap", 9);
    it.Add(dict);

    DataTable table = ToDictionary(it);
    foreach (DataColumn col in table.Columns)
        Console.Write("{0}\t", col.ColumnName);
    Console.WriteLine();
    foreach (DataRow row in table.Rows)
    {
        foreach (DataColumn column in table.Columns)
            Console.Write("{0}\t", row[column].ToString());
        Console.WriteLine();
    }
    Console.ReadLine();

}

And the output looks like...

a       b       c       bob     tom     Yip Yip Yap Yap
1       2       3
                        34      37
                                        8       9

Writing nested collection to datatable c#

1 Answers1