Apply Conditional Formatting in Worksheets with C++

This article is designed to provide a detailed understanding of how to add conditional formatting to a range of cells in a worksheet.

Conditional formatting is an advanced feature in Microsoft Excel that allows you to apply formats to a range of cells and have that formatting change depending on the value of the cell or a formula. For example, the background of a cell may be red to highlight a negative value, or the text color might be green for a positive value. When the value of the cell meets the format condition, the format is applied. If the value of the cell does not meet the format condition, the cell’s default formatting is used.

It’s possible to apply conditional formatting with Microsoft Office Automation, but that has its drawbacks. There are several reasons and issues involved: for example, security, stability, scalability, and speed. The main reason for finding another solution is that Microsoft itself strongly recommends against Office Automation for software solutions.

This article shows how to create a console application and add conditional formatting to cells with a few simple lines of code using the Aspose.Cells API.

Using Aspose.Cells to Apply Conditional Formatting Based on Cell Value

Download and Install Aspose.Cells.
- Download Aspose.Cells for C++.
- Install it on your development computer.
  All Aspose components, when installed, work in evaluation mode. The evaluation mode has no time limit and it only injects watermarks into the produced documents.
Create a project.
Start your C++ development environment and create a new console application.
Add references.
Add a reference to Aspose.Cells to your project, for example, add a reference to ...\Program Files\Aspose\Aspose.Cells\Bin\Net1.0\Aspose.Cells.dll.
Apply conditional formatting based on cell value.
Below is the code used to accomplish the task. It applies conditional formatting to a cell.

#include <iostream>
#include "Aspose.Cells.h"
using namespace Aspose::Cells;

int main()
{
    Aspose::Cells::Startup();

    // Source directory path
    U16String srcDir(u"..\\Data\\01_SourceDirectory\\");

    // Output directory path
    U16String outDir(u"..\\Data\\02_OutputDirectory\\");

    // Instantiating a Workbook object
    Workbook workbook;

    // Get the first worksheet
    Worksheet sheet = workbook.GetWorksheets().Get(0);

    // Add an empty conditional formatting
    int index = sheet.GetConditionalFormattings().Add();

    // Get the FormatConditionCollection
    FormatConditionCollection fcs = sheet.GetConditionalFormattings().Get(index);

    // Set the conditional format range
    CellArea ca = CellArea::CreateCellArea(0, 0, 0, 0);

    // Add the cell area to the format condition collection
    fcs.AddArea(ca);

    // Add condition
    int conditionIndex = fcs.AddCondition(FormatConditionType::CellValue, OperatorType::Between, u"50", u"100");

    // Get the format condition
    FormatCondition fc = fcs.Get(conditionIndex);

    // Set the background color
    fc.GetStyle().SetBackgroundColor(Color::Red());

    // Save the Excel file
    workbook.Save(outDir + u"output.out.xls", SaveFormat::Auto);

    std::cout << "Conditional formatting applied successfully!" << std::endl;

    Aspose::Cells::Cleanup();
}

When the above code is executed, conditional formatting is applied to cell A1 in the first worksheet of the output file (output.xls). The conditional formatting applied to A1 depends on the cell value. If the cell value of A1 is between 50 and 100, the background color is red due to the conditional formatting applied.

Using Aspose.Cells to Apply Conditional Formatting Based on Formula

Applying conditional formatting based on a formula (Code Snippet)
Below is the code to accomplish the task. It applies conditional formatting to cell B3.

#include <iostream>
#include "Aspose.Cells.h"
using namespace Aspose::Cells;

int main()
{
    Aspose::Cells::Startup();

    // Source directory path
    U16String srcDir(u"..\\Data\\01_SourceDirectory\\");

    // Output directory path
    U16String outDir(u"..\\Data\\02_OutputDirectory\\");

    // Create workbook
    Workbook workbook;

    // Get the first worksheet
    Worksheet sheet = workbook.GetWorksheets().Get(0);

    // Add an empty conditional formatting
    int index = sheet.GetConditionalFormattings().Add();

    // Get the conditional formatting collection
    FormatConditionCollection fcs = sheet.GetConditionalFormattings().Get(index);

    // Set the conditional format range
    CellArea ca = CellArea::CreateCellArea(2, 1, 2, 1);

    // Add the area to the conditional formatting
    fcs.AddArea(ca);

    // Add condition
    int conditionIndex = fcs.AddCondition(FormatConditionType::Expression);

    // Get the format condition
    FormatCondition fc = fcs.Get(conditionIndex);

    // Set the formula for the condition
    fc.SetFormula1(u"=IF(SUM(B1:B2)>100,TRUE,FALSE)");

    // Set the background color
    Style style = fc.GetStyle();
    style.SetBackgroundColor(Color::Red());
    fc.SetStyle(style);

    // Set the formula for cell B3
    sheet.GetCells().Get(u"B3").SetFormula(u"=SUM(B1:B2)");

    // Set the value for cell C4
    sheet.GetCells().Get(u"C4").PutValue(u"If the sum of B1:B2 is greater than 100, B3 will have RED background");

    // Save the Excel file
    workbook.Save(outDir + u"output.out.xls", SaveFormat::Auto);

    std::cout << "Conditional formatting applied successfully!" << std::endl;

    Aspose::Cells::Cleanup();
}

When the above code is executed, conditional formatting is applied to cell B3 in the first worksheet of the output file (output.xls). The conditional formatting applied depends on a formula that calculates the value of B3 as the sum of B1 and B2.

Apply Advanced Conditional Formatting with C++