private async void dropdown_Clicked(object sender, EventArgs e)
{
var button = (Button)sender;
var dropdown = new ContentView();
var dropdownHeight = 200;
var dropdownContent = new Frame()
{
Margin = new Thickness(20, 0),
CornerRadius = 20,
HasShadow = false,
HeightRequest = dropdownHeight,
BackgroundColor = Color.FromHex("#F5F5F5"),
};
var list = new ListView()
{
BackgroundColor = Color.FromHex("#00000000"),
ItemsSource = new List <string> {
"test option 1",
"test option 2",
"test option 3",
"test option 4",
"test option 5",
}
};
list.ItemSelected += ((object s, SelectedItemChangedEventArgs ev) =>
{
button.Text = ((string)((ListView)s).SelectedItem);
OverlayHelper.Close();
});
dropdownContent.Content = list;
dropdown.Content = dropdownContent;
var dropdownContentY = button.Y + button.Height + 5;
var parent = (VisualElement)button.Parent;
while (parent != null)
{
if (parent.Parent.GetType() == typeof(VisualElement) || parent.Parent.GetType() == typeof(ScrollView))
{
if (parent.Parent.GetType() == typeof(VisualElement))
{
dropdownContentY += parent.Y;
parent = (VisualElement)parent.Parent;
}
else if (parent.Parent.GetType() == typeof(ScrollView))
{
dropdownContentY -= ((ScrollView)parent.Parent).ScrollY;
parent = null;
}
}
}
if ((dropdownContentY + dropdownHeight) > Application.Current.MainPage.Height)
{
dropdownContentY -= (dropdownHeight + button.Height + 10);
}
await Task.Run(() =>
{
OverlayHelper.Open(dropdown, AbsoluteLayoutFlags.WidthProportional,
new Rectangle(0, dropdownContentY, 1, dropdownHeight), Color.FromHex("#00000000"));
});
}
private void OK_Clicked(object sender, System.EventArgs e)
{
OverlayHelper.Close();
}