asp.net后台生成table的合并有关问题

//从grd的第rowIndex行colIndex列单元格以下count行合并
public static void 合并行(GridView grd, int rowIndex, int colIndex, int count)
{
    grd.Rows[rowIndex].Cells[colIndex].RowSpan = count;
    for (var i = rowIndex + 1; i < rowIndex + count; i++)
        grd.Rows[i].Cells[colIndex].Visible = false;
}

//从grd的第rowIndex行colIndex列单元格向右count列合并
public static void 合并列(GridView grd, int rowIndex, int colIndex, int count)
{
    grd.Rows[rowIndex].Cells[colIndex].ColumnSpan = count;
    for (var i = 1; i < count; i++)
        grd.Rows[rowIndex].Cells[colIndex + i].Visible = false;
}