Step 2: Creating a Managed-Code UDF

After you have added a reference to Microsoft.Office.Excel.Server.Udf.dll to your project, the next step is to create some custom functions and mark them with the Serviços do Excel user-defined function (UDF) attributes.

You must mark your UDF class with the Microsoft.Office.Excel.Server.Udf.UdfClass attribute, and mark the UDF methods with the Microsoft.Office.Excel.Server.Udf.UdfMethod attribute.

Any methods that are not marked with the Microsoft.Office.Excel.Server.Udf.UdfMethod attribute in the UDF assembly will be ignored, because they will not be considered UDF methods.

The Microsoft.Office.Excel.Server.Udf.UdfMethod attribute has an IsVolatile property. You use the IsVolatile property to specify a UDF method as volatile or nonvolatile. The IsVolatile property takes a Boolean value. The default value is false, which means that particular UDF method is nonvolatile.

Creating UDFs

Para adicionar diretivas

Os tipos a utilizar são definidos no espaço de nomes Microsoft.Office.Excel.Server.Udf . Adding a using (or Imports) directive at the top of the Class1.cs file will allow you to use the types in Microsoft.Office.Excel.Server.Udf without having to fully qualify the types in the namespace.

Para adicionar esta diretiva, adicione o seguinte código ao início do código no ficheiro Class1.cs, depois de using System.Text:
```
using Microsoft.Office.Excel.Server.Udf;
```
```
Imports Microsoft.Office.Excel.Server.Udf
```

To mark a UDF class and methods

Marque Class1 como uma classe UDF ao adicionar o seguinte atributo imediatamente acima public class Class1de :
```
[UdfClass]
```
```
<UdfClass>_
```
Create a function that takes a number (of type double), and in the function, multiply the number by 9. The function is a UDF method that is nonvolatile. Adicione o seguinte código a Class1:
```
[UdfMethod]
public double MyDouble(double d)
{
    return d * 9;
}
```
```
<UdfMethod> _
Public Function MyDouble(ByVal d As Double) As Double
    Return d * 9
End Function
```
Observação

[!OBSERVAçãO] The default value for the IsVolatile property is false, which means that particular UDF method is nonvolatile. Por conseguinte, é suficiente marcar um método UDF não complicado como [UdfMethod]. Não é necessário marcá-la como [UdfMethod(IsVolatile = false)].

Create another function that returns the current date using the System.DateTime.Today property. The function is a UDF method that is volatile. Adicione o seguinte código a Class1:

[UdfMethod(IsVolatile = true)]
public DateTime ReturnDateTimeToday()
{
    return (DateTime.Today);
}

<UdfMethod(IsVolatile := True)> _
Public Function ReturnDateTimeToday() As Date
    Return (Date.Today)
End Function

To build the project

On the Build menu, click Build Solution.
You should find SampleUdf.dll assembly in the directory where you have saved your project.

Código completo

O exemplo a seguir é o código completo no arquivo de exemplo Class1.cs descrito nos procedimentos anteriores.

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Office.Excel.Server.Udf;

namespace SampleUdf
{
    [UdfClass]
    public class Class1
    {
        [UdfMethod]
        public double MyDouble(double d)
        {
            return d * 9;
        }

        [UdfMethod(IsVolatile = true)]
        public DateTime ReturnDateTimeToday()
        {
            return (DateTime.Today);
        }
    }
}

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.Office.Excel.Server.Udf

Namespace SampleUdf
    <UdfClass> _
    Public Class Class1
        <UdfMethod> _
        Public Function MyDouble(ByVal d As Double) As Double
            Return d * 9
        End Function

        <UdfMethod(IsVolatile := True)> _
        Public Function ReturnDateTimeToday() As Date
            Return (Date.Today)
        End Function
    End Class
End Namespace

Confira também

Tarefas

Conceitos

Last updated on 2026-05-14