ICustomFunction Interface
Defines properties and methods required to implement your own worksheet function.
Namespace: DevExpress.Spreadsheet.Functions
Assembly: DevExpress.Spreadsheet.v24.2.Core.dll
NuGet Package: DevExpress.Spreadsheet.Core
Declaration
Related API Members
The following members return ICustomFunction objects:
Remarks
using DevExpress.Spreadsheet;
using DevExpress.Spreadsheet.Functions;
using DevExpress.XtraSpreadsheet;
// Create a custom function and add it to the global scope.
SphereMassFunction customFunction = new SphereMassFunction();
if (!workbook.Functions.GlobalCustomFunctions.Contains(customFunction.Name))
workbook.Functions.GlobalCustomFunctions.Add(customFunction);
public class SphereMassFunction : ICustomFunction
{
const string functionName = "SPHEREMASS";
readonly ParameterInfo[] functionParameters;
public SphereMassFunction()
{
// Missing optional parameters do not result in an error message.
this.functionParameters = new ParameterInfo[] { new ParameterInfo(ParameterType.Value, ParameterAttributes.Required),
new ParameterInfo(ParameterType.Value, ParameterAttributes.Optional)};
}
public string Name { get { return functionName; } }
ParameterInfo[] IFunction.Parameters { get { return functionParameters; } }
ParameterType IFunction.ReturnType { get { return ParameterType.Value; } }
bool IFunction.Volatile { get { return false; } }
ParameterValue IFunction.Evaluate(IList<ParameterValue> parameters, EvaluationContext context)
{
double radius;
double density = 1000;
ParameterValue radiusParameter;
ParameterValue densityParameter;
if (parameters.Count == 2)
{
densityParameter = parameters[1];
if (densityParameter.IsError)
return densityParameter;
else
density = densityParameter.NumericValue;
}
radiusParameter = parameters[0];
if (radiusParameter.IsError)
return radiusParameter;
else
radius = radiusParameter.NumericValue;
return (4 * Math.PI) / 3 * Math.Pow(radius,3) * density;
}
string IFunction.GetName(CultureInfo culture)
{
return functionName;
}
}
See Also