Convert GridView DataSource To DataTable using Linq and C# in ASP.Net

Hi priyajsr,

You are assigning List to GvOrder gridview. So you can't directly convert List to DataTable as the GridView DataSource is List. So you need to first convert the List to DataTable and then bind to gridview. Form that gridview you can get the DataSource as DataTable by type casting it.

Refer the below sample.

Here I am making use of Microsoft’s Northwind Database. You can download it from here.

Download and install Northwind Database

HTML

<table>
    <tr>
        <td>
            <asp:GridView runat="server" ID="GvOrder" Caption="From Entity" />
        </td>
        <td>
            <asp:GridView runat="server" ID="GvOrder1" Caption="From DataSource" />
        </td>
    </tr>
</table>

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        NorthwindEntities entity = new NorthwindEntities();
        var db1 = (from ordermst in entity.Orders
                    where ordermst.ShipCountry.Equals("Finland")
                    select new
                    {
                        CustomerID = ordermst.CustomerID,
                        OrderID = ordermst.OrderID
                    }).Take(10).ToList();
        DataTable dt = ConvertToDataTable(db1);
        GvOrder.DataSource = dt;
        GvOrder.DataBind();

        DataTable dt1 = new DataTable();
        dt1 = GvOrder.DataSource as DataTable;
        GvOrder1.DataSource = dt1;
        GvOrder1.DataBind();

    }
}

private DataTable ConvertToDataTable<T>(IList<T> data)
{
    PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(typeof(T));
    DataTable table = new DataTable();
    foreach (PropertyDescriptor prop in properties)
    {
        table.Columns.Add(prop.Name, Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType);
    }
    foreach (T item in data)
    {
        DataRow row = table.NewRow();
        foreach (PropertyDescriptor prop in properties)
        {
            row[prop.Name] = prop.GetValue(item) ?? DBNull.Value;
        }
        table.Rows.Add(row);
    }
    return table;
}

VB.Net

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not IsPostBack Then
        Dim entity As New NorthwindEntities()
        Dim db1 = (From ordermst In entity.Orders Where (ordermst.ShipCountry.Equals("Finland")) _
                Select New With { _
                   Key .CustomerID = ordermst.CustomerID, _
                   Key .OrderID = ordermst.OrderID _
                  }).Take(10).ToList()
        Dim dt As DataTable = ConvertToDataTable(db1)
        GvOrder.DataSource = dt
        GvOrder.DataBind()

        Dim dt1 As New DataTable()
        dt1 = TryCast(GvOrder.DataSource, DataTable)
        GvOrder1.DataSource = dt1
        GvOrder1.DataBind()
    End If
End Sub

Private Function ConvertToDataTable(Of T)(data As IList(Of T)) As DataTable
    Dim properties As PropertyDescriptorCollection = TypeDescriptor.GetProperties(GetType(T))
    Dim table As New DataTable()
    For Each prop As PropertyDescriptor In properties
        table.Columns.Add(prop.Name, If(Nullable.GetUnderlyingType(prop.PropertyType), prop.PropertyType))
    Next
    For Each item As T In data
        Dim row As DataRow = table.NewRow()
        For Each prop As PropertyDescriptor In properties
            row(prop.Name) = If(prop.GetValue(item), DBNull.Value)
        Next
        table.Rows.Add(row)
    Next
    Return table
End Function

OutPut