Update StringConcatFunction.cs

Author: ritazakhodyaeva

CS/Dashboard_StringConcatAggregate/StringConcatFunction.cs

@@ -1,11 +1,10 @@
 using DevExpress.Data.Filtering;
 using DevExpress.DataAccess.Criteria;
-using DevExpress.DataAccess.Native.ExpressionEditor;
 using System;
 using System.Collections.Generic;
 
 namespace Dashboard_StringConcatAggregate {
- class StringConcatFunction : ICustomAggregateFunction, ICustomFunctionOperatorBrowsable, ICustomFunctionOperatorCategory {
+ class StringConcatFunction : ICustomAggregateFunction, ICustomFunctionOperatorBrowsable {
  public string Name => "StringConcat";
 
  public int MinOperandCount => 1;
@@ -17,16 +16,14 @@ class StringConcatFunction : ICustomAggregateFunction, ICustomFunctionOperatorBr
 
  public FunctionCategory Category => DevExpress.Data.Filtering.FunctionCategory.Text;
 
- public string FunctionCategory => "Aggregate";
-
- public Type CreateEvaluationState(Type inputType) {
- return typeof(StringConcatState);
- }
-
  public object Evaluate(params object[] operands) {
  throw new NotImplementedException();
  }
 
+ public Type GetAggregationContextType(Type inputType) {
+ return typeof(StringConcatState);
+ }
+
  public bool IsValidOperandCount(int count) {
  return count <= MaxOperandCount && count >= MinOperandCount;
  }