[]
Gets or sets the first formula of this conditional format.
The property value represents the first comparison value or expression associated with the conditional formatting rule. Depending on the rule type, it can be a constant value, a string value, a cell reference, or a formula.
object Formula1 { get; set; }
Property Formula1 As Object
worksheet.Range["A1:B5"].Value = new object[,] {{1, 2}, {0, 1}, {0, 0}, {0, 3}, {4, 5}};
IFormatCondition condition = (IFormatCondition) worksheet.Range["B1:B5"]
.FormatConditions.Add(FormatConditionType.Expression, FormatConditionOperator.None, "=A1>0", null);
condition.Interior.Color = Color.Yellow;
object formula1 = condition.Formula1;