Where does ConditionalFormattingRule live in the IronXL API?

ConditionalFormattingRule is a class in the IronXL.Formatting namespace, shipped in IronXL.dll. CreateConditionalFormattingRule returns one, which you style and then add to a worksheet with AddConditionalFormatting.

How do you create a conditional formatting rule in C#?

Call CreateConditionalFormattingRule on a worksheet's ConditionalFormatting accessor, passing a comparison operator and a value. Configure the returned rule's FontFormatting, BorderFormatting, or PatternFormatting, then add it to a cell range with AddConditionalFormatting.

Which ComparisonOperator does ComparisonOperation use?

The ComparisonOperation property uses the operator from IronXL.Formatting.Enums.ComparisonOperator, such as LessThan or Between. That is a different type from the ComparisonOperator in IronXL.DataValidations, which applies to data validation rules instead.

Class ConditionalFormattingRule

Represents a description of a conditional formatting rule.

Inheritance

System.Object

ConditionalFormattingRule

Namespace: IronXL.Formatting

Assembly: IronXL.dll

Syntax

public class ConditionalFormattingRule : Object

Styling cells when they meet a condition runs through ConditionalFormattingRule. One rule pairs a test (a comparison against a value or a category) with the formatting applied when the test passes, so a developer expresses "color this cell red when it is below 8" as a single object. It is the rule a developer builds behind a search like "C# Excel conditional formatting rule".

A rule is produced by CreateConditionalFormattingRule on a worksheet's conditional formatting accessor, then attached to a cell range with AddConditionalFormatting. The factory call sets the rule's ComparisonOperation and Formula1; the returned object is then configured with the styles to apply and added to the sheet. The rule belongs to the formatting pass that runs when the workbook is saved or evaluated.

Two groups of members do the work. The condition group decides when the rule fires: ConditionType reports the category (cell-value comparison, formula, color scale, and similar), ComparisonOperation holds the operator from the IronXL.Formatting.Enums.ComparisonOperator set such as LessThan or Between, and Formula1 and Formula2 carry the compared values, with Formula2 used by range operators like Between. The styling group decides what the rule does: FontFormatting sets font and color, BorderFormatting sets borders, and PatternFormatting sets the background fill and pattern. Note that ComparisonOperation uses the formatting enum, which differs from the same-named operator in IronXL.DataValidations used for data validation rules; the two are separate types with separate members.

using IronXL;
using IronXL.Formatting;

WorkSheet sheet = WorkBook.Create().DefaultWorkSheet;
ConditionalFormattingRule rule =
    sheet.ConditionalFormatting.CreateConditionalFormattingRule(ComparisonOperator.LessThan, "8");
rule.FontFormatting.IsBold = true;
sheet.ConditionalFormatting.AddConditionalFormatting("A1:A10", rule);

The conditional formatting how-to walks through creating and styling a rule, the conditional formatting example applies one to a range, and the style cells example covers the fonts and borders a rule sets.

Properties

BorderFormatting

Gets the border formatting.

Declaration

public IBorderFormatting BorderFormatting { get; }

Property Value

Type	Description
IBorderFormatting	The border formatting.

ComparisonOperation

The comparison function used when the type of conditional formatting is Set to CellValueIs

Declaration

public ComparisonOperator ComparisonOperation { get; }

Property Value

Type	Description
ComparisonOperator	The conditional format operator.

ConditionType

Type of conditional formatting rule. MUST be either CellValueIs or NPOI.SS.Formula.Formula

Declaration

public ConditionType ConditionType { get; }

Property Value

Type	Description
ConditionType	The type of condition.

FontFormatting

Gets the font formatting.

Declaration

public IFontFormatting FontFormatting { get; }

Property Value

Type	Description
IFontFormatting	The font formatting.

Formula1

The formula used to Evaluate the first operand for the conditional formatting rule.

If the condition type is CellValueIs this field is the first operand of the comparison. If type is NPOI.SS.Formula.Formula, this formula is used to determine if the conditional formatting is applied.

If comparison type is NPOI.SS.Formula.Formula the formula MUST be a Boolean function

Declaration

public string Formula1 { get; }

Property Value

Type	Description
System.String	The first formula of the rule

Formula2

The formula used to Evaluate the second operand of the comparison when condition type is CellValueIs and operator is either Between or NotBetween

Declaration

public string Formula2 { get; }

Property Value

Type	Description
System.String	The second formula of the rule.

PatternFormatting

Gets the pattern formatting.

Declaration

public IPatternFormatting PatternFormatting { get; }

Property Value

Type	Description
IPatternFormatting	The pattern formatting.