windowsforms-devexpress-dot-xtraeditors-dot-filtering-dot-excelfilteringdataeventargs-dc5f68e9.md
Removes all items from the collection of data values by which the column being processed can be filtered.
Namespace : DevExpress.XtraEditors.Filtering
Assembly : DevExpress.XtraEditors.v25.2.dll
NuGet Package : DevExpress.Win.Navigation
public bool ClearData()
Public Function ClearData As Boolean
| Type | Description |
|---|---|
| Boolean |
true if the items are successfully removed; otherwise, false.
|
Use the ClearData() method to clear items in the DataItems collection.
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.
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);
}
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.
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.
See Also
ExcelFilteringDataEventArgs Class