EDIT: I forgot to mention, but there was a Pull Request approved and added to the Xamarin.Forms repository that is currently available in Xamarin.Forms v2.3.4-pre1 and should release with the next major update. https://developer.xamarin.com/releases/xamarin-forms/xamarin-forms-2.3/2.3.4-pre1/
It’s unfortunate that Xamarin.Forms’ Picker
does not ship with any ability to bind the options. To get around this, we can create a pretty simple control: The BindablePicker
public partial class BindablePicker : Picker { public BindablePicker() { InitializeComponent(); this.SelectedIndexChanged += OnSelectedIndexChanged; } public static BindableProperty ItemsSourceProperty = BindableProperty.Create("ItemsSource", typeof(IEnumerable), typeof(BindablePicker), default(IEnumerable), propertyChanged: OnItemsSourceChanged); public static BindableProperty SelectedItemProperty = BindableProperty.Create("SelectedItem", typeof(object), typeof(BindablePicker), default(object), propertyChanged: OnSelectedItemChanged); public IEnumerable ItemsSource { get { return (IEnumerable)GetValue(ItemsSourceProperty); } set { SetValue(ItemsSourceProperty, value); } } public object SelectedItem { get { return (object)GetValue(SelectedItemProperty); } set { SetValue(SelectedItemProperty, value); } } private static void OnItemsSourceChanged(BindableObject bindable, object oldvalue, object newvalue) { var picker = bindable as BindablePicker; picker.Items.Clear(); if (newvalue != null) { foreach (var item in (IEnumerable)newvalue) { picker.Items.Add(item.ToString()); } } // TODO: Add more methods for removing items here } private void OnSelectedIndexChanged(object sender, EventArgs eventArgs) { if (SelectedIndex < 0 || SelectedIndex > Items.Count - 1) { SelectedItem = null; } else { SelectedItem = Items[SelectedIndex]; } } private static void OnSelectedItemChanged(BindableObject bindable, object oldvalue, object newvalue) { var picker = bindable as BindablePicker; if (newvalue != null) { picker.SelectedIndex = picker.Items.IndexOf(newvalue.ToString()); } } }
Then you can use the picker in your XAML like so:
<views:BindablePicker ItemsSource="{Binding TypeList}" Title="Type" SelectedItem="{Binding CurrentType}"/>;
intellitect.com also has a great post on how to do something similar to allow for an enum
to be bound to the options.
Hi Alex, this is a good tip. but could you also explain how could I set selectedItem when loading data from database? Currently xamarin form picker doesn’t work, even if I bind the value to selected Item.
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Hi did you manage to figure this out? I am stuck on the same issue, any assistance would be greatly appreciated
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This is a greaat post thanks
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