I don't know anything provided by the Framework (beyond what you want to avoid) that would do what you want but (as I suspect you know) it would be pretty easy to create something simple yourself:
private DataTable GetDataTableFromDGV(DataGridView dgv) {
var dt = new DataTable();
foreach (DataGridViewColumn column in dgv.Columns) {
if (column.Visible) {
// You could potentially name the column based on the DGV column name (beware of dupes)
// or assign a type based on the data type of the data bound to this DGV column.
dt.Columns.Add();
}
}
object[] cellValues = new object[dgv.Columns.Count];
foreach (DataGridViewRow row in dgv.Rows) {
for (int i = 0; i < row.Cells.Count; i++) {
cellValues[i] = row.Cells[i].Value;
}
dt.Rows.Add(cellValues);
}
return dt;
}