GemBox.Spreadsheet is a .NET component that enables you to read, write, edit, convert, and print spreadsheet files from your .NET applications using one simple API.

Excel Conditional Formatting in C# and VB.NET

Following example shows how to apply various kinds of Conditional Formatting rules to cell ranges of an Excel worksheet with C# and VB.NET.

Conditional Formatting resolution is currently not implemented in GemBox.Spreadsheet. Conditional Formatting is loaded from and saved to XLSX file format only.

Screenshot
Excel Conditional Formatting Screenshot

See the full code below, use Run Example to execute.

using System;
using System.Collections.Generic;
using System.Text;
using GemBox.Spreadsheet;
using GemBox.Spreadsheet.ConditionalFormatting;
using GemBox.Spreadsheet.PivotTables;

class Sample
{
    [STAThread]
    static void Main(string[] args)
    {
        // If using Professional version, put your serial key below.
        SpreadsheetInfo.SetLicense("FREE-LIMITED-KEY");

        ExcelFile ef = new ExcelFile();
        ExcelWorksheet ws = ef.Worksheets.Add("Conditional Formatting");

        int rowCount = 20;

        // Specify sheet formatting.
        ws.Rows[0].Style.Font.Weight = ExcelFont.BoldWeight;
        ws.Columns[0].SetWidth(3, LengthUnit.Centimeter);
        ws.Columns[1].SetWidth(3, LengthUnit.Centimeter);
        ws.Columns[2].SetWidth(3, LengthUnit.Centimeter);
        ws.Columns[3].SetWidth(3, LengthUnit.Centimeter);
        ws.Columns[3].Style.NumberFormat = "[$$-409]#,##0.00";
        ws.Columns[4].SetWidth(3, LengthUnit.Centimeter);
        ws.Columns[4].Style.NumberFormat = "yyyy-mm-dd";

        var cells = ws.Cells;

        // Specify header row.
        cells[0, 0].Value = "Departments";
        cells[0, 1].Value = "Names";
        cells[0, 2].Value = "Years of Service";
        cells[0, 3].Value = "Salaries";
        cells[0, 4].Value = "Deadlines";

        // Insert random data to sheet.
        var random = new Random();
        var departments = new string[] { "Legal", "Marketing", "Finance", "Planning", "Purchasing" };
        var names = new string[] { "John Doe", "Fred Nurk", "Hans Meier", "Ivan Horvat" };
        for (int i = 0; i < rowCount; ++i)
        {
            cells[i + 1, 0].Value = departments[random.Next(departments.Length)];
            cells[i + 1, 1].Value = names[random.Next(names.Length)] + ' ' + (i + 1).ToString();
            cells[i + 1, 2].SetValue(random.Next(1, 31));
            cells[i + 1, 3].SetValue(random.Next(10, 101) * 100);
            cells[i + 1, 4].SetValue(DateTime.Now.AddDays(random.Next(-1, 2)));
        }

        // Apply shading to alternate rows in a worksheet using 'Formula' based conditional formatting.
        ws.ConditionalFormatting.AddFormula(ws.Cells.Name, "MOD(ROW(),2)=0").
            Style.FillPattern.PatternBackgroundColor = SpreadsheetColor.FromName(ColorName.Accent1Lighter40Pct);
        ws.ConditionalFormatting.AddFormula(ws.Cells.Name, "MOD(ROW(),2)=1").
            Style.FillPattern.PatternBackgroundColor = SpreadsheetColor.FromName(ColorName.Accent5Lighter80Pct);

        // Apply '2-Color Scale' conditional formatting to 'Years of Service' column.
        ws.ConditionalFormatting.Add2ColorScale("C2:C" + (rowCount + 1));

        // Apply '3-Color Scale' conditional formatting to 'Salaries' column.
        ws.ConditionalFormatting.Add3ColorScale("D2:D" + (rowCount + 1));

        // Apply 'Data Bar' conditional formatting to 'Salaries' column.
        ws.ConditionalFormatting.AddDataBar("D2:D" + (rowCount + 1));

        // Apply 'Icon Set' conditional formatting to 'Years of Service' column.
        ws.ConditionalFormatting.AddIconSet("C2:C" + (rowCount + 1)).IconStyle = SpreadsheetIconStyle.FourTrafficLights;

        // Apply green font color to cells in a 'Years of Service' column which have values between 15 and 20.
        ws.ConditionalFormatting.AddContainValue("C2:C" + (rowCount + 1), ContainValueOperator.Between, 15, 20).
            Style.Font.Color = SpreadsheetColor.FromName(ColorName.Green);

        // Apply double red border to cells in a 'Names' column which contain text 'Doe'.
        ws.ConditionalFormatting.AddContainText("B2:B" + (rowCount + 1), ContainTextOperator.Contains, "Doe").
            Style.Borders.SetBorders(MultipleBorders.Outside, SpreadsheetColor.FromName(ColorName.Red), LineStyle.Double);

        // Apply red shading to cells in a 'Deadlines' column which are equal to yesterday's date.
        ws.ConditionalFormatting.AddContainDate("E2:E" + (rowCount + 1), ContainDateOperator.Yesterday).
            Style.FillPattern.PatternBackgroundColor = SpreadsheetColor.FromName(ColorName.Red);

        // Apply bold font weight to cells in a 'Salaries' column which have top 10 values.
        ws.ConditionalFormatting.AddTopOrBottomRanked("D2:D" + (rowCount + 1), false, 10).
            Style.Font.Weight = ExcelFont.BoldWeight;

        // Apply double underline to cells in a 'Years of Service' column which have below average value.
        ws.ConditionalFormatting.AddAboveOrBelowAverage("C2:C" + (rowCount + 1), true).
            Style.Font.UnderlineStyle = UnderlineStyle.Double;

        // Apply italic font style to cells in a 'Departments' column which have duplicate values.
        ws.ConditionalFormatting.AddUniqueOrDuplicate("A2:A" + (rowCount + 1), true).
            Style.Font.Italic = true;

        ef.Save("Conditional Formatting.xlsx");
    }
}
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports GemBox.Spreadsheet
Imports GemBox.Spreadsheet.ConditionalFormatting
Imports GemBox.Spreadsheet.PivotTables

Module Samples

    Sub Main()

        ' If using Professional version, put your serial key below.
        SpreadsheetInfo.SetLicense("FREE-LIMITED-KEY")

        Dim ef As ExcelFile = New ExcelFile
        Dim ws As ExcelWorksheet = ef.Worksheets.Add("Conditional Formatting")

        Dim rowCount As Integer = 20

        ' Specify sheet formatting.
        ws.Rows(0).Style.Font.Weight = ExcelFont.BoldWeight
        ws.Columns(0).SetWidth(3, LengthUnit.Centimeter)
        ws.Columns(1).SetWidth(3, LengthUnit.Centimeter)
        ws.Columns(2).SetWidth(3, LengthUnit.Centimeter)
        ws.Columns(3).SetWidth(3, LengthUnit.Centimeter)
        ws.Columns(3).Style.NumberFormat = "[$$-409]#,##0.00"
        ws.Columns(4).SetWidth(3, LengthUnit.Centimeter)
        ws.Columns(4).Style.NumberFormat = "yyyy-mm-dd"

        Dim cells = ws.Cells

        ' Specify header row.
        cells(0, 0).Value = "Departments"
        cells(0, 1).Value = "Names"
        cells(0, 2).Value = "Years of Service"
        cells(0, 3).Value = "Salaries"
        cells(0, 4).Value = "Deadlines"

        ' Insert random data to sheet.
        Dim random = New Random()
        Dim departments = New String() {"Legal", "Marketing", "Finance", "Planning", "Purchasing"}
        Dim names = New String() {"John Doe", "Fred Nurk", "Hans Meier", "Ivan Horvat"}
        For i As Integer = 0 To rowCount - 1
            cells(i + 1, 0).Value = departments(random.Next(departments.Length))
            cells(i + 1, 1).Value = names(random.Next(names.Length)) + " "c + (i + 1).ToString()
            cells(i + 1, 2).SetValue(random.Next(1, 31))
            cells(i + 1, 3).SetValue(random.Next(10, 101) * 100)
            cells(i + 1, 4).SetValue(DateTime.Now.AddDays(random.Next(-1, 2)))
        Next

        ' Apply shading to alternate rows in a worksheet using 'Formula' based conditional formatting.
        ws.ConditionalFormatting.AddFormula(ws.Cells.Name, "MOD(ROW(),2)=0").
            Style.FillPattern.PatternBackgroundColor = SpreadsheetColor.FromName(ColorName.Accent1Lighter40Pct)
        ws.ConditionalFormatting.AddFormula(ws.Cells.Name, "MOD(ROW(),2)=1").
            Style.FillPattern.PatternBackgroundColor = SpreadsheetColor.FromName(ColorName.Accent5Lighter80Pct)

        ' Apply '2-Color Scale' conditional formatting to 'Years of Service' column.
        ws.ConditionalFormatting.Add2ColorScale("C2:C" & (rowCount + 1))

        ' Apply '3-Color Scale' conditional formatting to 'Salaries' column.
        ws.ConditionalFormatting.Add3ColorScale("D2:D" & (rowCount + 1))

        ' Apply 'Data Bar' conditional formatting to 'Salaries' column.
        ws.ConditionalFormatting.AddDataBar("D2:D" & (rowCount + 1))

        ' Apply 'Icon Set' conditional formatting to 'Years of Service' column.
        ws.ConditionalFormatting.AddIconSet("C2:C" & (rowCount + 1)).IconStyle = SpreadsheetIconStyle.FourTrafficLights

        ' Apply green font color to cells in a 'Years of Service' column which have values between 15 and 20.
        ws.ConditionalFormatting.AddContainValue("C2:C" & (rowCount + 1), ContainValueOperator.Between, 15, 20).
            Style.Font.Color = SpreadsheetColor.FromName(ColorName.Green)

        ' Apply double red border to cells in a 'Names' column which contain text 'Doe'.
        ws.ConditionalFormatting.AddContainText("B2:B" & (rowCount + 1), ContainTextOperator.Contains, "Doe").
            Style.Borders.SetBorders(MultipleBorders.Outside, SpreadsheetColor.FromName(ColorName.Red), LineStyle.Double)

        ' Apply red shading to cells in a 'Deadlines' column which are equal to yesterday's date.
        ws.ConditionalFormatting.AddContainDate("E2:E" & (rowCount + 1), ContainDateOperator.Yesterday).
            Style.FillPattern.PatternBackgroundColor = SpreadsheetColor.FromName(ColorName.Red)

        ' Apply bold font weight to cells in a 'Salaries' column which have top 10 values.
        ws.ConditionalFormatting.AddTopOrBottomRanked("D2:D" & (rowCount + 1), False, 10).
            Style.Font.Weight = ExcelFont.BoldWeight

        ' Apply double underline to cells in a 'Years of Service' column which have below average value.
        ws.ConditionalFormatting.AddAboveOrBelowAverage("C2:C" & (rowCount + 1), True).
            Style.Font.UnderlineStyle = UnderlineStyle.Double

        ' Apply italic font style to cells in a 'Departments' column which have duplicate values.
        ws.ConditionalFormatting.AddUniqueOrDuplicate("A2:A" & (rowCount + 1), True).
            Style.Font.Italic = True

        ef.Save("Conditional Formatting.xlsx")

    End Sub

End Module

Check next sample.