The top bottom rule checks whether the values in the top or bottom of a cell range match with the required values in the cell. In case the values don't match, the data is considered as invalid. This rule can be added using the properties and methods of the ITop10 interface.

The following options are available while adding top bottom rule in a worksheet:

• Top 10
• Top 10%
• Bottom 10
• Bottom 10%
• Above Average
• Below Average

Refer to the following example code to add top bottom rule in a worksheet.

// Adding ToBottom rule
worksheet.Range["A1:A5"].Value = new object[,]
{
    {1},
    {2},
    {3},
    {4},
    {5}
};

ITop10 condition = worksheet.Range["A1:A5"].FormatConditions.AddTop10();
condition.TopBottom = TopBottom.Top10Top;
condition.Rank = 50;
condition.Percent = true;
condition.Interior.Color = Color.FromRGB(128, 0, 128);