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using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms.Internals;
namespace Xamarin.Forms.Controls
{
internal sealed class ListViewSelectionColor : ContentPage
{
[Preserve (AllMembers = true)]
internal sealed class GroupHeaderTemplate : ViewCell
{
public GroupHeaderTemplate ()
{
var label = new Label { BackgroundColor = Color.Red };
label.SetBinding (Label.TextProperty, "Key");
View = label;
}
}
[Preserve (AllMembers = true)]
internal sealed class GroupItemTemplate : ViewCell
{
public GroupItemTemplate ()
{
var label = new Label { BackgroundColor = Color.Green };
label.SetBinding (Label.TextProperty, "Name");
View = label;
}
}
[Preserve (AllMembers = true)]
internal sealed class ItemTemplate : ViewCell
{
public ItemTemplate ()
{
var label = new Label { BackgroundColor = Color.Green };
label.SetBinding (Label.TextProperty, "Name");
View = label;
}
}
[Preserve (AllMembers = true)]
internal sealed class Artist
{
public string Name { get; private set; }
public Artist (string name)
{
Name = name;
}
}
[Preserve (AllMembers = true)]
internal sealed class Grouping<K, T> : ObservableCollection<T>
{
public K Key { get; private set; }
public Grouping (K key, IEnumerable<T> values)
{
Key = key;
foreach (T value in values) {
Items.Add (value);
}
}
}
Button _swapListButton;
[Preserve (AllMembers = true)]
public ListViewSelectionColor()
{
Title = "ListView ScrollTo";
var itemSource = new [] {
new { Name = "John Hassel" },
new { Name = "Brian Eno" },
new { Name = "Rober Fripp" },
new { Name = "Edgar Froese" }
};
var groupedItemSource = new List<Grouping<string, Artist>> {
new Grouping<string, Artist> ("Prog", new List<Artist> { new Artist ("King Crimson"), new Artist ("Yes"), new Artist ("Rush") }),
new Grouping<string, Artist> ("Techno", new List<Artist> { new Artist ("Juan Atkins"), new Artist ("Jeff Mills"), new Artist ("Gerald Donald") } ),
new Grouping<string, Artist> ("Pop", new List<Artist> { new Artist ("Japan"), new Artist ("Roxy Music"), new Artist ("Talking Heads") }),
};
var normalList = new ListView {
ItemTemplate = new DataTemplate (typeof (ItemTemplate)),
ItemsSource = itemSource
};
var groupedList = new ListView {
IsGroupingEnabled = true,
GroupHeaderTemplate = new DataTemplate (typeof (GroupHeaderTemplate)),
ItemTemplate = new DataTemplate (typeof (GroupItemTemplate)),
ItemsSource = groupedItemSource
};
var currentList = normalList;
_swapListButton = new Button {
Text = "Swap List Type",
Command = new Command (() => {
if (currentList == normalList) {
SetContent (groupedList);
currentList = groupedList;
} else {
SetContent (normalList);
currentList = normalList;
}
})
};
var clear = new Button {
Text = "Clear",
Command = new Command (() => {
currentList.SelectedItem = null;
})
};
Content = new StackLayout {
Children = {
new StackLayout {
Orientation = StackOrientation.Horizontal,
Children = {
_swapListButton,
clear
}
},
normalList
}
};
}
void SetContent (ListView list)
{
Content = new StackLayout {
Children = {
_swapListButton,
list
}
};
}
}
}
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