WPF DataGrid转化为DataTable？

Question

WPF DataGrid的数据源由ItemsSource绑定，如何将DataGrid转化为DataTable？
补充：
ItemsSource = "{Binding ChargeList}"

ChargeList 的类型 ：ObservableCollection

Answer 1

public static DataTable DataGrid2Table(DataGrid dg)
    {
        DataTable dt=new DataTable();
        for (int i= 0; i< dg.Columns.Count; i++)
        {
            DataColumn dc = new DataColumn(dg.Columns[i].Name.ToString());
            dt.Columns.Add(dc);
        }
        for (int i = 0; i< dg.Rows.Count; i++)
        {
            DataRow dr = dt.NewRow();
            for (int j = 0; j < dg.Columns.Count; j++)
            {
                dr[j] = dg.Rows[i].Cells[j].Value.ToString();
            }
            dt.Rows.Add(dr);
        }
        return dt;
    }