Custom Formula in WPF Spreadsheet

14 Aug 20261 minute to read

SfSpreadsheet allows you to add custom formulas to its function library by using the AddFunction method of FormulaEngine.

C#

spreadsheet.WorkbookLoaded += spreadsheet_WorkbookLoaded;

void spreadsheet_WorkbookLoaded(object sender, WorkbookLoadedEventArgs args)
{
    foreach (var grid in args.GridCollection)
        AddCustomFormula(grid); 
  
  //Computing the formula at runtime

   var range = spreadsheet.ActiveSheet.Range["B2"];
   spreadsheet.ActiveGrid.SetCellValue(range,"=Find(sample)");
}  

private void AddCustomFormula(SpreadsheetGrid grid)
{

  // Add a formula named Find to the Library.
   grid.FormulaEngine.AddFunction("Find", new FormulaEngine.LibraryFunction(ComputeLength));      
}    

//Implementation of formula
    
public string ComputeLength(string range)
{
    // Calculate the length of the supplied string.
    return range.Length.ToString();
}

NOTE

For more information, see the WPF Spreadsheet Editor feature tour or browse the WPF Spreadsheet examples on GitHub.