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Converting a List to a DataTable

4.98/5 (26 votes)
18 Jul 2011CPOL 99.1K  
I wrote this because I was interested in a Q&A question which asked for exactly that. Since I quite often use DataTables to transfer data, and to display it for debugging I knocked up an extension method to do it.
Then I realized that arrays implement the IList interface... Hmm. So now, I have an Extension Method that converts any List or array based data into a DataTable.
For debugging, that's pretty useful...
So, here it is, for posterity:
C#
public static class ExtensionMethods
    {
    /// <summary>
    /// Converts a List to a datatable
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="data"></param>
    /// <returns></returns>
    public static DataTable ToDataTable<T>(this IList<T> data)
        {
        PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(typeof(T));
        DataTable dt = new DataTable();
        for (int i = 0; i < properties.Count; i++)
            {
            PropertyDescriptor property = properties[i];
            dt.Columns.Add(property.Name, property.PropertyType);
            }
        object[] values = new object[properties.Count];
        foreach (T item in data)
            {
            for (int i = 0; i < values.Length; i++)
                {
                values[i] = properties[i].GetValue(item);
                }
            dt.Rows.Add(values);
            }
        return dt;
        }
    }


VB
Public NotInheritable Class ExtensionMethods
    ''' <summary>
    ''' Converts a List to a datatable
    ''' </summary>
    ''' <typeparam name="T"></typeparam>
    ''' <param name="data"></param>
    ''' <returns></returns>
    <System.Runtime.CompilerServices.Extension> _
    Public Shared Function ToDataTable(Of T)(data As IList(Of T)) As DataTable
        Dim properties As PropertyDescriptorCollection = TypeDescriptor.GetProperties(GetType(T))
        Dim dt As New DataTable()
        For i As Integer = 0 To properties.Count - 1
            Dim [property] As PropertyDescriptor = properties(i)
            dt.Columns.Add([property].Name, [property].PropertyType)
        Next
        Dim values As Object() = New Object(properties.Count - 1) {}
        For Each item As T In data
            For i As Integer = 0 To values.Length - 1
                values(i) = properties(i).GetValue(item)
            Next
            dt.Rows.Add(values)
        Next
        Return dt
    End Function
End Class

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)