How to convert DataGrid to dataTable

To convert your dataGrid into data table whith header row you can follow this steps:

1) create the method to retrive the cell

  static public DataGridCell GetCell(DataGrid dg, int row, int column)
    {
        DataGridRow rowContainer = GetRow(dg, row);

        if (rowContainer != null)
        {
            DataGridCellsPresenter presenter = GetVisualChild<DataGridCellsPresenter>(rowContainer);
            DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
            if (cell == null)
            {
                dg.ScrollIntoView(rowContainer, dg.Columns[column]);
                cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
            }
            return cell;
        }
        return null;
    }

2) Iterate through all items and pass the content to dada table "cell"

    private void DataGridToDataTable()
    {
        DataTable dt = new DataTable();
        var j = byte.MinValue;//header row handler
        dt.Rows.Add();
        foreach (DataGridColumn column in dataGrid1.Columns)
        {                
            dt.Columns.Add(column.GetValue(NameProperty).ToString());
            dt.Rows[byte.MinValue][j++] = column.Header;
        }

        //data rows handler
        for (int i = byte.MinValue ; i < dataGrid1.Items.Count; i++)
        {
            dt.Rows.Add();
            for (j = Byte.MinValue; j < dataGrid1.Columns.Count; j++)
            {
                DataGridCell dgc = GetCell(dataGrid1, i, j);
                dt.Rows[i + 1][j] =  ((dgc.Content) as TextBlock).Text;
            }
        }
    }  

Keep in mind to use this methods you must will reference this using

using System.Windows.Media;
using System.Data;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;

And here a helper class just to use it.

 /// <summary>
/// Class to help to retrive the Data Grid Contain
/// </summary>
public static class DataGridHelper
{
    /// <summary>
    /// Retrive the cell contains
    /// </summary>
    /// <param name="dg">DataGrid</param>
    /// <param name="row">row</param>
    /// <param name="column">column</param>
    /// <returns>DataGrid Cell content</returns>
    static public DataGridCell GetCell(DataGrid dg, int row, int column)
    {
        DataGridRow rowContainer = GetRow(dg, row);

        if (rowContainer != null)
        {
            DataGridCellsPresenter presenter = GetVisualChild<DataGridCellsPresenter>(rowContainer);

            // try to get the cell but it may possibly be virtualized
            DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
            if (cell == null)
            {
                // now try to bring into view and retreive the cell
                dg.ScrollIntoView(rowContainer, dg.Columns[column]);
                cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
            }
            return cell;
        }
        return null;
    }
    /// <summary>
    /// Get row content
    /// </summary>
    /// <param name="dg">Datagrid</param>
    /// <param name="index">Index</param>
    /// <returns>DataGridRow</returns>
    static public DataGridRow GetRow(DataGrid dg, int index)
    {
        DataGridRow row = (DataGridRow)dg.ItemContainerGenerator.ContainerFromIndex(index);
        if (row == null)
        {
            // may be virtualized, bring into view and try again
            dg.ScrollIntoView(dg.Items[index]);
            row = (DataGridRow)dg.ItemContainerGenerator.ContainerFromIndex(index);
        }
        return row;
    }
    static T GetVisualChild<T>(Visual parent) where T : Visual
    {
        T child = default(T);
        int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
        for (int i = 0; i < numVisuals; i++)
        {
            Visual v = (Visual)VisualTreeHelper.GetChild(parent, i);
            child = v as T;
            if (child == null)
            {
                child = GetVisualChild<T>(v);
            }
            if (child != null)
            {
                break;
            }
        }
        return child;
    }
}

This is the way to transfer all the records from DATAGRID to DATATABLE without using the LOOP.

VB:

Dim dt As New DataTable
dt = CType(DataGrid1.ItemsSource, DataView).ToTable

C#:

DataTable dt = new DataTable();
dt = ((DataView)DataGrid1.ItemsSource).ToTable();  

It depends how the datagrid is populated. If the DataContext property is set to a DataTable then you can simply just retrieve this value and cast to a DataTable.

There is no direct method to convert this to a DataTable from the DataGrid element.

If you wanted to do this manually, you would have to create an instance of the DataTable, then create the rows from the Items in the DataGrid using a loop.