## CustomFunctionDefinition class

Definition of custom function for calculating with user's custom engine.

```csharp
public class CustomFunctionDefinition
```

## Constructors

| Name | Description |
| --- | --- |
| [CustomFunctionDefinition](customfunctiondefinition/)() | The default constructor. |

## Methods

| Name | Description |
| --- | --- |
| virtual [GetArrayModeParameters](../../aspose.cells/customfunctiondefinition/getarraymodeparameters/)(string) | Gets the indices of given custom function's parameters that need to be calculated in array mode. |

### Examples

```csharp
namespace AsposeCellsExamples
{
    using Aspose.Cells;
    using System;

    public class CustomFunctionDefinitionDemo
    {
        public static void CustomFunctionDefinitionExample()
        {
            // Create a new workbook
            Workbook workbook = new Workbook();

            // Create a new CustomFunctionDefinition instance
            CustomFunctionDefinition customFunctionDefinition = new CustomFunctionDefinition();

            // Create a new FormulaParseOptions instance and set the CustomFunctionDefinition
            FormulaParseOptions formulaParseOptions = new FormulaParseOptions
            {
                CustomFunctionDefinition = customFunctionDefinition
            };

            // Add a worksheet to the workbook
            Worksheet worksheet = workbook.Worksheets[0];

            // Define a custom formula
            string customFormula = "=MY_CUSTOM_FUNCTION(A1, B1)";

            // Parse the custom formula using the FormulaParseOptions
            worksheet.Cells["C1"].Formula = customFormula;
            worksheet.Cells["C1"].SetFormula(customFormula, formulaParseOptions);

            // Save the workbook
            workbook.Save("CustomFunctionDefinitionExample.xlsx");
            workbook.Save("CustomFunctionDefinitionExample.pdf");
            return;
        }
    }
}
```

### See Also

* namespace [Aspose.Cells](../../aspose.cells/)
* assembly [Aspose.Cells](../../)