ExcelFilteringDataEventArgs.DataItems Property

Provides access to the collection of data values by which the column being processed can be filtered, and the corresponding display texts.

Namespace: DevExpress.XtraEditors.Filtering

Assembly: DevExpress.XtraEditors.v23.2.dll

NuGet Package: DevExpress.Win.Navigation

Declaration

C#

public List<ExcelFilterDataItem> DataItems { get; }

VB.NET

Public ReadOnly Property DataItems As List(Of ExcelFilterDataItem)

Property Value

Type	Description
List<DevExpress.XtraEditors.Filtering.ExcelFilterDataItem>	An object that specifies the collection of data values by which the column being processed can be filtered.

Remarks

The DataItems property provides access to the collection of objects that specify data values by which the column being processed can be filtered. To add, remove an item, or clear the collection, use the AddData, RemoveData, and ClearData() methods.

Example

A default column filter menu contains data values available in the column. The code below shows how to populate a filter menu with custom values.

Note

The example uses the grid control. The vertical grid, tree list, and pivot grid controls provide a similar API.

In this example, the processed column contains comma-separated values that can be treated as individual tokens. The FilterPopupExcelData event allows you to populate the menu with custom tokens instead of the available data values.

C#

readonly static char[] separators = new char[] { ',', ' ' };

void OnFilterPopupExcelData(object sender, FilterPopupExcelDataEventArgs e) {
    // Create a collection of tokens based on data values.
    var tokens = new HashSet<string>();
    for(int i = 0; i < e.Values.Length; i++) {
        var parts = ((string)e.Values[i]).Split(separators, StringSplitOptions.RemoveEmptyEntries);
        for(int j = 0; j < parts.Length; j++)
            tokens.Add(parts[j]);
    }
    // Remove the default data values from the filter menu.
    e.ClearData();
    // Populate the menu with the created tokens.
    foreach(string t in tokens.OrderBy(x => x))
        e.AddData(t, t);
}

VB.NET

Private ReadOnly Shared separators() As Char = { ","c, " "c }

Private Sub OnFilterPopupExcelData(ByVal sender As Object, ByVal e As FilterPopupExcelDataEventArgs)
    ' Create a collection of tokens based on data values.
    Dim tokens = New HashSet(Of String)()
    For i As Integer = 0 To e.Values.Length - 1
        Dim parts = DirectCast(e.Values(i), String).Split(separators, StringSplitOptions.RemoveEmptyEntries)
        For j As Integer = 0 To parts.Length - 1
            tokens.Add(parts(j))
        Next j
    Next i
    ' Remove the default data values from the filter menu.
    e.ClearData()
    ' Populate the menu with the created tokens.
    For Each t As String In tokens.OrderBy(Function(x) x)
        e.AddData(t, t)
    Next t
End Sub

If you have populated the menu with custom tokens, you also must handle the following events:

• FilterPopupExcelQueryFilterCriteria — to convert the selected tokens to the corresponding filter criteria that should be applied to data (direct conversion). This conversion is processed when the user selects a token in the menu/applies the selected tokens/closes the menu.

  C#

  void OnFilterPopupExcelQueryFilterCriteria(object sender, FilterPopupExcelQueryFilterCriteriaEventArgs e) {
      var viewModel = e.Value as ICollectionValueViewModel<string>;
      var property = new OperandProperty(e.Path);
      var functions = viewModel.Values
          .Select(x => new FunctionOperator(FunctionOperatorType.Contains, property, x));
      e.FilterCriteria = CriteriaOperator.Or(functions);
  }
  

  VB.NET

  Private Sub OnFilterPopupExcelQueryFilterCriteria(ByVal sender As Object, ByVal e As FilterPopupExcelQueryFilterCriteriaEventArgs)
      Dim viewModel = TryCast(e.Value, ICollectionValueViewModel(Of String))
      Dim [property] = New OperandProperty(e.Path)
      Dim functions = viewModel.Values.Select(Function(x) New FunctionOperator(FunctionOperatorType.Contains, [property], x))
      e.FilterCriteria = CriteriaOperator.Or(functions)
  End Sub
  

• FilterPopupExcelParseFilterCriteria — to convert the applied filter criteria to the corresponding tokens that should be selected in the menu (reverse conversion). This conversion is processed when the user opens the menu.

  C#

  void OnFilterPopupExcelParseFilterCriteria(object sender, FilterPopupExcelParseFilterCriteriaEventArgs e) {
      var func = e.FilterCriteria as FunctionOperator;
      if(!ReferenceEquals(func, null))
          e.SetValue(((OperandValue)func.Operands[1]).Value);
      var group = e.FilterCriteria as GroupOperator;
      if(!ReferenceEquals(group, null)) {
          var values = group.Operands
              .OfType<FunctionOperator>()
              .Select(x => ((OperandValue)x.Operands[1]).Value);
          e.SetValues(values.ToArray());
      }
  }
  

  VB.NET

  Private Sub OnFilterPopupExcelParseFilterCriteria(ByVal sender As Object, ByVal e As FilterPopupExcelParseFilterCriteriaEventArgs)
      Dim func = TryCast(e.FilterCriteria, FunctionOperator)
      If Not ReferenceEquals(func, Nothing) Then
          e.SetValue(CType(func.Operands(1), OperandValue).Value)
      End If
      Dim group = TryCast(e.FilterCriteria, GroupOperator)
      If Not ReferenceEquals(group, Nothing) Then
          Dim values = group.Operands.OfType(Of FunctionOperator)().Select(Function(x) (CType(x.Operands(1), OperandValue)).Value)
          e.SetValues(values.ToArray())
      End If
  End Sub