ICustomCriteriaOperatorQueryable.GetMethodInfo() Method

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

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v23.2.dll

NuGet Packages: DevExpress.Win.PivotGrid, DevExpress.Win.TreeMap, DevExpress.Xpo

NuGet Package: DevExpress.Xpo

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 associated with a custom criterion, based on specified function parameters.

Remarks

The code below shows a sample GetMethodInfo implementation.

C#

public class MyConcatFunction : ICustomFunctionOperatorBrowsable, ICustomFunctionOperatorFormattable, 
    ICustomCriteriaOperatorQueryable {
    const string FunctionName = nameof(MyConcat);
    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(params string[] strings) {
        StringBuilder sb = new StringBuilder();
        foreach(string str in strings) {
            sb.Append(str);
        }
        return sb.ToString();
    }

    #region ICustomCriteriaOperatorQueryable Members
    public System.Reflection.MethodInfo GetMethodInfo() {
        return typeof(MyConcatFunction).GetMethod(FunctionName);
    }
    #endregion
}

VB.NET

Public Class MyConcatFunction
    Implements ICustomFunctionOperatorBrowsable, ICustomFunctionOperatorFormattable, _
    ICustomCriteriaOperatorQueryable
    Private Const FunctionName As String = NameOf(MyConcat)
    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(ParamArray ByVal strings() As String) As String
        Dim sb As New StringBuilder()
        For Each str As String In strings
            sb.Append(str)
        Next str
        Return sb.ToString()
    End Function

    #Region "ICustomCriteriaOperatorQueryable 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.