DataGridに表示されている文字列の検索

private int GetRowIndex(DataView dv,int StartIdx,string Keyword)
{
    int ret = -1;
    for (int i = StartIdx;i<dv.Count;i++)
    {
        if ((string)dv[i].Row[0] == Keyword)
        {
            ret = i;
            break;
        }
    }
    return ret;
}

DataGridCell cell = new DataGridCell();
int row = ((DataView)dataGrid1.DataSource).Table.Rows.Count;
int col = ((DataView)dataGrid1.DataSource).Table.Columns.Count;
for (int i = 0;i<row;i++)
{
    cell.RowNumber = i;
    for (int ii = 0;ii<col;ii++)
    {
        cell.ColumnNumber = ii;
        string s = dataGrid1[cell] as string;
        
        if ((s != null) && (s == myFindKeyword))
        {
            dataGrid1.Select(i);
            return;
        }
    }
}