ICustomFunction是一個非常實用的功能，它能夠在模板文件中或通過代碼定義自定義/用戶定義的函數。接下來，我們就將使用Aspose.Cells創建和檢驗一個用戶定義的函數：

1. 創建項目：啟動Visual Studio. NET并創建一個新的控制臺應用程序。
2. 添加引用：
   該項目將使用Aspose.Cells。所以，你必須到在項目中為Aspose.Cells組件添加引用。例如，添加一個引用到.... \Program Files\Aspose\Aspose.Cells for .NET\Bin\Net1.0\Aspose.Cells.dll
3. 編寫代碼，創建和檢驗一個用戶定義的函數：

[C#]

using System;
using System.Collections.Generic;
using System.Text;
using Aspose.Cells;

namespace UsingICustomFunction
{
    public class CustomFunction :   ICustomFunction
    {

        public object CalculateCustomFunction(string functionName, System.Collections.ArrayList paramsList, System.Collections.ArrayList contextObjects)
        {

            //get value of first parameter
            decimal firstParamB1 = System.Convert.ToDecimal(paramsList[0]);

            //get value of second parameter
            Array secondParamC1C5 = (Array)(paramsList[1]);

          ;  decimal total = 0M;

            // get every item value of second parameter
            foreach (object[] value in secondParamC1C5)
          ;  {

      ;          total += System.Convert.ToDecimal(value[0]);

            }

            total = total / firstParamB1;

            //return result of the function
            return total;

        }
    }

   class Program
    {
        static void Main(string[] args)
        {

        //Open the workbook
        Workbook workbook = new Workbook();

        //Obtaining the reference of the first worksheet
        Worksheet worksheet = workbook.Worksheets[0];

        //Adding a sample value to "A1" cell
         worksheet.Cells["B1"].PutValue(5);

        //Adding a sample value to "A2" cell
        worksheet.Cells["C1"].PutValue(100);

        //Adding a sample value to "A3" cell
        worksheet.Cells["C2"].PutValue(150);

        //Adding a sample value to "B1" cell
        worksheet.Cells["C3"].PutValue(60);

        //Adding a sample value to "B2" cell
        worksheet.Cells["C4"].PutValue(32);

        //Adding a sample value to "B2" cell
        worksheet.Cells["C5"].PutValue(62);

        //Adding custom formula to Cell A1
        workbook.Worksheets[0].Cells["A1"].Formula = "=MyFunc(B1,C1:C5)";

        //Calcualting Formulas
        workbook.CalculateFormula(false, new CustomFunction());

        //Assign resultant value to Cell A1
        workbook.Worksheets[0].Cells["A1"].PutValue(workbook.Worksheets[0].Cells["A1"].Value);

        //Save the file
        workbook.Save("C:\\UsingICustomFunction.xls");
        }
    }
}
 

[VB]

 Imports Aspose.Cells

Module Module1

    Sub Main()

        'Open the workbook
        Dim workbook As New Workbook

        'Obtaining the reference of the first worksheet
        Dim worksheet As Worksheet = workbook.Worksheets(0)

        'Adding a sample value to "A1" cell
        worksheet.Cells("B1").PutValue(5)

        'Adding a sample value to "A2" cell
        worksheet.Cells("C1").PutValue(100)

        'Adding a sample value to "A3" cell
        worksheet.Cells("C2").PutValue(150)

        'Adding a sample value to "B1" cell
        worksheet.Cells("C3").PutValue(60)

        'Adding a sample value to "B2" cell
        worksheet.Cells("C4").PutValue(32)

        'Adding a sample value to "B2" cell
    ;    worksheet.Cells("C5").PutValue(62)

        'Adding custom formula to Cell A1
        workbook.Worksheets(0).Cells("A1").Formula =

"=MyFunc(B1,C1:C5)"

        'Calcualting Formulas
        workbook.CalculateFormula(False, New

CustomFunction)

        'Assign resultant value to Cell A1
         workbook.Worksheets(0).Cells("A1").PutValue

(workbook.Worksheets(0).Cells("A1").Value)

        'Save the file
        workbook.Save("C:\\UsingICustomFunction.xls")
    End Sub

End Module

Public Class CustomFunction
    Implements ICustomFunction

    Function CalculateCustomFunction(ByVal functionName As

String, _
        ByVal paramsList As System.Collections.ArrayList, _
        ByVal contextObjects As

System.Collections.ArrayList) As Object _
        Implements ICustomFunction.CalculateCustomFunction

        'get value of first parameter
        Dim firstParamB1 As Decimal = CType

(paramsList.Item(0), Decimal)

        'get value of second parameter
        Dim secondParamC1C5 As Array = CType

(paramsList.Item(1), Array)

        Dim total As Decimal = 0

        ' get & add every item value of second parameter
        For Each value As Object In secondParamC1C5

            total += CType(value(0), Decimal)

        Next

        total = total / firstParamB1

        'return result of the function
  ;    ;  Return total

    End Function
End Class

代碼運行后的效果圖如下：