Check All Functionality in Grid

//

    /// Rows Check box check event.
    ///

    ///

    ///
    protected void chkItemChecked_CheckedChanged(object sender, EventArgs e)
    {
        try
        {
            ((sender as CheckBox).Parent.Parent as GridItem).Selected = (sender as CheckBox).Checked;
            AssignedHeaderCheckBoxState((sender as CheckBox).Checked);
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    ///

    /// Header check box click event select/Unselect all rows.
    ///

    ///
    ///
    protected void chkAllItems_CheckedChanged(object sender, EventArgs e)
    {
        try
        {
            if ((sender as CheckBox).Checked)
            {
                foreach (GridDataItem dataItem in RadGridCoverageAreaStates.MasterTableView.Items)
                {
                    (dataItem.FindControl("chkItemChecked") as CheckBox).Checked = true;
                    dataItem.Selected = true;
                }
            }
            else
            {
                foreach (GridDataItem dataItem in RadGridCoverageAreaStates.MasterTableView.Items)
                {
                    (dataItem.FindControl("chkItemChecked") as CheckBox).Checked = false;
                    dataItem.Selected = false;
                }
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
______________________
 ///

    /// Check/Uncheck Header Check Box on the basis of all rows Selection/UnSelection.
    ///

    ///
    private void AssignedHeaderCheckBoxState(bool bChecked)
    {
        int iCounter = 0;
        DataTable dtCityList = ((DataSet)ViewState["ProductCovarageAreaStates"]).Tables[0]; ;
        foreach (GridDataItem gdItem in RadGridCoverageAreaStates.Items)
            if ((gdItem.FindControl("chkItemChecked") as CheckBox).Checked == bChecked)
                iCounter++;
        if (dtCityList != null)
        {
            if (iCounter == dtCityList.Rows.Count)
            {
                foreach (GridHeaderItem HeaderItem in RadGridCoverageAreaStates.MasterTableView.GetItems(GridItemType.Header))
                {
                    ((CheckBox)(HeaderItem.FindControl("chkAllItems"))).Checked = bChecked;
                    break;
                }
            }
            else
            {
                foreach (GridHeaderItem HeaderItem in RadGridCoverageAreaStates.MasterTableView.GetItems(GridItemType.Header))
                {
                    ((CheckBox)(HeaderItem.FindControl("chkAllItems"))).Checked = false;
                    break;
                }
            }

        }
    }