ICustomFunctionOperatorQueryable.GetMethodInfo() Method

When implemented by a class, returns the metadata of a method associated with a custom function used in LINQ to XPO expressions.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v18.2.dll

Declaration

C#

MethodInfo GetMethodInfo()

VB.NET

Function GetMethodInfo As MethodInfo

Returns

Type	Description
MethodInfo	A MethodInfo object which identifies the method to be used to evaluate a custom function, based on specified function parameters.

Remarks

The code below shows a sample GetMethodInfo implementation.

C#

public class MyConcatFunction : ICustomFunctionOperatorBrowsable, ICustomFunctionOperatorFormattable,
    ICustomFunctionOperatorQueryable {
    const string FunctionName = "MyConcat";
    static readonly MyConcatFunction instance = new MyConcatFunction();
    public string ICustomFunctionOperator.Name {
        get { return FunctionName; }
    }
    // ...

    // The method name must match the function name 
    // returned by the ICustomFunctionOperator.Name property implementation.
    public static string MyConcat(string string1, string string2, string string3, string string4) {
        return (string)instance.Evaluate(string1, string2, string3, string4);
    }
    #region ICustomFunctionOperatorQueryable Members
    public System.Reflection.MethodInfo GetMethodInfo() {
        return typeof(MyConcatFunction).GetMethod(FunctionName);
    }
    #endregion
}

VB.NET

Public Class MyConcatFunction
    Implements ICustomFunctionOperatorBrowsable, ICustomFunctionOperatorFormattable, _
    ICustomFunctionOperatorQueryable
    Private Const FunctionName As String = "MyConcat"
    Private Shared ReadOnly instance As New MyConcatFunction()
    Public ReadOnly Property ICustomFunctionOperator_Name() As String _
    Implements ICustomFunctionOperator.Name
        Get
            Return FunctionName
        End Get
    End Property
    ' ...

    ' The method name must match the function name 
    ' returned by the ICustomFunctionOperator.Name property implementation.
    Public Shared Function MyConcat(ByVal string1 As String, ByVal string2 As String, _
    ByVal string3 As String, ByVal string4 As String) As String
        Return CStr(instance.Evaluate(string1, string2, string3, string4))
    End Function
    #Region "ICustomFunctionOperatorQueryable Members"
    Public Function GetMethodInfo() As System.Reflection.MethodInfo
        Return GetType(MyConcatFunction).GetMethod(FunctionName)
    End Function
    #End Region
End Class

To see the entire example, see the How to: Implement Custom Functions and Criteria in LINQ to XPO.