The control should allow customizations in its filtering functionality, for example, the developers should be able let RadComboBox match "Á" when the user types "A".

Place a RadComboBox control in a RadPane. Make it floating and dock it again. When selection is changed, the SelectionChanged event is fired multiple times.

Allow the developers to style the TextBox area of a editable RadComboBox - add icons, change the string, format the text etc.

It might also be nice to take it one step further and give the option to choose the key that fires an update off

When filtering is enabled, enter text that doesn't exist in the items and when the focus is removed the text entered is deleted, but it should stay.
The solution of this issue was implemented by a new feature in the control which determines if the Text of the RadComboBox should be updated on LostFocus or not.
Simply set the UpdateTextOnLostFocus dependency property of the control to "False". By default its value is True and no change in behavior should be observed.
The UpdateTextOnLostFocus dependency property is available in the 2015 Q2 SP1 release.

When the ComboBox is non editable.

When the CheckBox is focused the issue is appearing.

Available in LIB version 2016.2.905, it will be also available in the 2016 R3 Release.

When IsEditable is set to true the SelectedItem is not updated if you delete the SelectedItem's text to match another existing item.

Available in the 2016 R3 Release.

Please check our help article for more information: 
http://docs.telerik.com/devtools/wpf/controls/radcombobox/features/multiple-selection

According to the following article, when the UpdateSelectionOnLostFocus property is set to True and you enter a text that cannot update the selection, once the control loses the focus, the typed text should stay in the textbox. 
https://docs.telerik.com/devtools/wpf/controls/radcombobox/howto/perform-selection-only-lost-focus

However, this doesn't happen if an item is already selected. In this case, the searched text is cleared. If you do not have a selection, then the text stays on lost focus. 

To work this around, you can cache the value of the RadComboBox's Text property in the PreviewLostKeyboardFocus event handler and then restore it in the LostFocus event handler. 

private string textCache;
private void RadComboBox_PreviewLostKeyboardFocus(object sender, System.Windows.Input.KeyboardFocusChangedEventArgs e)
{
	this.textCache = this.comboBox.Text;
}
private void RadComboBox_LostFocus(object sender, RoutedEventArgs e)
{
	this.comboBox.Text = this.textCache;
}

Combobox with 2 items -- "Item1"   and "it": typing "it" selects the 1st item which is "Item1" and it should select the second one which is "it"

IsEditable=True and ReadOnly=True

RadComboBox with IsEditable = true, IsReadOnly = true and IsFilteringEnabled = true. Select an item and then in order for the filtering to work you have to delete the selected text with Backspace

After RadComboBoxs DropDown (PopUp) is open moving the focus with Shift+Tab skips the Combo, Tab does not skip it


Available in R2 2015 Release (v.2015.2.623.40)