GrapeCity.Documents.Excel.CustomFunction.Evaluate

Evaluate Method

Evaluate(object[], ICalcContext)

Calculates the result of the custom function.

This method is called by the calculation engine when the custom function is evaluated. The arguments array contains the argument values passed to the function, and context provides information about the worksheet cell being calculated.

If AcceptErrors returns true, error values can be passed in arguments for custom handling. Otherwise, calculation can stop before this method is called when an argument evaluates to an error.

Declaration

public abstract object Evaluate(object[] arguments, ICalcContext context)

Public MustOverride Function Evaluate(arguments As Object(), context As ICalcContext) As Object

Parameters

Type	Name	Description
object[]	arguments	The argument values passed to the custom function. Elements can be evaluated values produced by the formula engine; the array can be empty but is not typically `null`.
ICalcContext	context	The calculation context that identifies the worksheet, row, and column of the cell being calculated. This value can be used to implement context-sensitive logic.

Returns

Type	Description
object	The calculated result of the custom function.

Examples

CustomFunction function = new DoubleFunction();
ICalcContext calcContext = new SampleCalcContext(worksheet, 0, 0);
object result = function.Evaluate(new object[] { 21d }, calcContext);

class DoubleFunction : CustomFunction
{
    public DoubleFunction()
        : base("DOUBLE", FunctionValueType.Number)
    {
    }

    public override object Evaluate(object[] arguments, ICalcContext context)
    {
        return Convert.ToDouble(arguments[0]) * 2;
    }
}

class SampleCalcContext : ICalcContext
{
    public SampleCalcContext(IWorksheet worksheet, int row, int column)
    {
        Worksheet = worksheet;
        Row = row;
        Column = column;
    }

    public IWorksheet Worksheet { get; }
    public int Row { get; }
    public int Column { get; }
}