Unplanned
Last Updated: 16 May 2022 10:51 by ADMIN
Created by: Bobby
Comments: 1
Category: ComboBox
Type: Feature Request
1

Hi Team,

Please consider adding Open/Closed event for the comboBox's popup. The validation for this is I need to perform validation if a user closes the popup without making a selection.

SelectionChanged doesn't work here, because user never selected anything. Focus events are very finnicky because of the platform differences and input modalities.

The only sane options is to add an official PopupClosed event (and you don't even need custom EventArgs).

Thank you!

Bobby

 

Workaround

For now, I am using reflection+ nonPublic|Instance BindingFields to get a reference to the private RadPopup field of the RadComboBox. With that reference, I am subscribing to PropertyChanged and watching for value changes  of the IsOpen property. 

It goes without saying, this is a very resource intensive and unofficial approach.

public partial class MainPage : ContentPage
{
    private RadPopup internalPopup;

    public MainPage()
    {
        InitializeComponent();
    }

    protected override void OnAppearing()
    {
        base.OnAppearing();

        var popup = typeof(RadComboBox).GetField("popup", BindingFlags.NonPublic | BindingFlags.Instance)?.GetValue(ComboBox1);

        if (popup is RadPopup p1)
        {
            internalPopup = p1;
            internalPopup.PropertyChanged += InternalPopup_PropertyChanged;
        }
    }

    private void InternalPopup_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
    {
        if (e.PropertyName != nameof(RadPopup.IsOpen))
            return;
        
        if (internalPopup.IsOpen)
        {
            // Popup was opened
        }
        else
        {
            // Popup was closed
        }
    }

    protected override void OnDisappearing()
    {
        if (internalPopup != null)
            internalPopup.PropertyChanged -= InternalPopup_PropertyChanged;

        base.OnDisappearing();
    }
}

Unplanned
Last Updated: 08 Apr 2022 06:24 by Gerald
Created by: Gerald
Comments: 0
Category: ComboBox
Type: Feature Request
0

I would like to make the dropdown appear to the right of the ComboBox instead of showing up below the ComboBox. 

Provide an API for changing the DropDown position. For example, the DropDown could be visualized above or under the input control - similar to AutoCompleteView control

Unplanned
Last Updated: 19 Aug 2021 05:51 by ADMIN
Created by: Richard
Comments: 0
Category: ComboBox
Type: Feature Request
0
customize the combobox when in editing mode
Unplanned
Last Updated: 30 Jun 2021 07:01 by ADMIN
Created by: Andrew
Comments: 1
Category: ComboBox
Type: Feature Request
1

I would like the ComboBox to be able to handle hierarchical data sources by rendering TreeView, with checkboxes, in the dropdown.

For inspiration, see Kendo UI DropDownTree https://demos.telerik.com/kendo-ui/dropdowntree/checkboxes 

Unplanned
Last Updated: 19 Apr 2021 14:46 by ADMIN
Provide a way to make the vertical scrollbar visible in case there are a lot of items and users need to scroll down to check them. Currently scrollbar is available on iOS only.
Unplanned
Last Updated: 17 Dec 2020 11:56 by ADMIN
Created by: Didi
Comments: 0
Category: ComboBox
Type: Feature Request
8
Currently, while searching in the ComboBox all items in the dropdown are displayed and the searched results are highlighted. 
Provide a way to show just the highlighted searched results in the ComboBox. 
Unplanned
Last Updated: 10 Dec 2020 08:42 by ADMIN
Created by: Ishani
Comments: 0
Category: ComboBox
Type: Feature Request
1
I want to update ItemsSource on textchanged event.