.NET MAUI DropDownButton Events

Updated on May 9, 2026

The .NET MAUI DropDownButton emits a set of events that allow you to configure the component's behavior in response to specific user actions.

The .NET MAUI DropDownButton exposes the following events:

• Opening—Raised when the RadDropDownButton.IsOpen property is changing to true. The Opening event handler receives two parameters:

  • The sender argument which is of type RadDropDownButton.
  • A CancelEventArgs object which provides an option to cancel the Opening event by using the Cancel(bool) property.

• Opened—Raised when the drop-down is fully opened, including the completion of any open animation. The Opened event handler receives two parameters:

  • The sender argument which is of type RadDropDownButton.
  • An EventArgs object which provides information about the Opened event.

• Closed—Raised when the drop-down is fully closed, including the completion of any close animation. The Closed event handler receives two parameters:

  • The sender argument which is of type RadDropDownButton.
  • An EventArgs object which provides information about the Closed event.

The RadDropDownButton inherits the Clicked, Pressed, and Released events from the RadTemplatedButton.

Using the Opening, Opened and Closed Events

The following example demonstrates how to use the Opening, Opened, and Closed events.

1. Define the button in XAML:

XAML

<telerik:RadDropDownButton Content="Open drop-down"
                           Opening="OnDropDownOpening"
                           Opened="OnDropDownOpened"
                           Closed="OnDropDownClosed">
    <telerik:RadDropDownButton.DropDownContent>
        <VerticalStackLayout Padding="12" Spacing="6">
            <Label Text="Actions"
                   FontAttributes="Bold" />
            <telerik:RadTemplatedButton Content="New" />
            <telerik:RadTemplatedButton Content="Open" />
            <telerik:RadTemplatedButton Content="Save" />
        </VerticalStackLayout>
    </telerik:RadDropDownButton.DropDownContent>
</telerik:RadDropDownButton>

2. Add the telerik namespace:

XAML

xmlns:telerik="http://schemas.telerik.com/2022/xaml/maui"

3. Add the Opening, Opened and Closed event handlers:

C#

private void OnDropDownOpening(object sender, CancelEventArgs e)
{
    if (this.cancelOpeningCheckBox?.IsChecked == true)
    {
        e.Cancel = true;
        this.AppendLog("Opening was canceled.");
        return;
    }

    this.AppendLog("Opening");
}

private void OnDropDownOpened(object sender, System.EventArgs e)
{
    this.AppendLog("Opened");
}

private void OnDropDownClosed(object sender, System.EventArgs e)
{
    this.AppendLog("Closed");
}

private void AppendLog(string message)
{
    this.eventsLog.Text = string.IsNullOrEmpty(this.eventsLog.Text)
        ? message
        : $"{this.eventsLog.Text}\n{message}";
}

This is the result on WinUI:

For a runnable example demonstrating the DropDownButton events, see the SDKBrowser Demo Application and go to the DropDownButton > Features category.

See Also

• Configure the Button Content and Indicator
• Configure the Drop-Down Part
• Style the DropDownButton
• Command
• Animation