From f4062dc5a6f01edf040aaf2766eb3ecd7635dfa7 Mon Sep 17 00:00:00 2001
From: w-mj <w.mingjian@yahoo.com>
Date: Sun, 28 Apr 2019 21:55:02 +0800
Subject: [PATCH] bind observable collection on labelListView

---
 FileManager_UWP/Controls/LabelListControl.cs  | 48 ++++++++++++++++++-
 .../Controls/LabelListControl.xaml            | 13 ++++-
 FileManager_UWP/View/TestLabelView.xaml       | 11 ++++-
 FileManager_UWP/View/TestLabelView.xaml.cs    | 10 ++++
 4 files changed, 77 insertions(+), 5 deletions(-)

diff --git a/FileManager_UWP/Controls/LabelListControl.cs b/FileManager_UWP/Controls/LabelListControl.cs
index 8927ab6..de59b87 100644
--- a/FileManager_UWP/Controls/LabelListControl.cs
+++ b/FileManager_UWP/Controls/LabelListControl.cs
@@ -1,5 +1,7 @@
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Diagnostics;
 using System.Linq;
 using System.Runtime.InteropServices.WindowsRuntime;
 using Windows.UI.Xaml;
@@ -7,18 +9,60 @@ using Windows.UI.Xaml.Controls;
 using Windows.UI.Xaml.Data;
 using Windows.UI.Xaml.Documents;
 using Windows.UI.Xaml.Input;
+using Windows.UI.Xaml.Markup;
 using Windows.UI.Xaml.Media;
 
 // The Templated Control item template is documented at https://go.microsoft.com/fwlink/?LinkId=234235
 
 namespace FileManager_UWP.Controls {
-    public sealed class LabelListControl: Control {
+
+    public class LabelListControl: ItemsControl {
         public LabelListControl() {
             this.DefaultStyleKey = typeof(LabelListControl);
+            //var itemSource = new ObservableCollection<string>();
+            //itemSource.CollectionChanged += ItemsSource_CollectionChanged;
+            //ItemsSource = itemSource;
+            //Debug.WriteLine(itemSource.ToString());
+        }
+
+        private void ItemsSource_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e) {
+            Debug.WriteLine("Add ELEMENT");
+            OnApplyTemplate();
+        }
+
+        public new ObservableCollection<string> ItemsSource {
+            get { return (ObservableCollection<string>)GetValue(ItemsControl.ItemsSourceProperty); }
+            set { SetValue(ItemsControl.ItemsSourceProperty, value); }
+        }
+
+        public new static readonly DependencyProperty ItemsSourceProperty =
+             DependencyProperty.Register(
+                 "ItemsSource", typeof(ObservableCollection<string>), typeof(LabelListControl),
+                 new PropertyMetadata(null, OnItemsChanged));
+
+        private static void OnItemsChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args) {
+            Debug.WriteLine("Add Element.");
+            LabelListControl target = obj as LabelListControl;
+            ObservableCollection<string> oldValue = (ObservableCollection<string>)args.OldValue;
+            ObservableCollection<string> newValue = (ObservableCollection<string>)args.NewValue;
+            if (oldValue != newValue) {
+                target.ItemsSource = newValue;
+                target.OnApplyTemplate();
+            }
         }
 
         protected override void OnApplyTemplate() {
-            ((TextBlock)GetTemplateChild("LabelTextBlock")).Text = "测试自定义控件";
+            TextBlock textBlock = (TextBlock)GetTemplateChild("LabelTextBlock");
+            textBlock.Text = "测试自定义控件\n";
+            ListView listView = (ListView)GetTemplateChild("LabelListView");
+            //listView.ItemsSource = ItemsSource;
+            ItemsSource.CollectionChanged += ItemsSource_CollectionChanged;
+            Debug.WriteLine(ItemsSource.ToString());
+            if (ItemsSource != null) {
+                textBlock.Text += (ItemsSource as ICollection<string>).Count().ToString();
+            } else {
+                textBlock.Text += "0";
+            }
         }
     }
 }
diff --git a/FileManager_UWP/Controls/LabelListControl.xaml b/FileManager_UWP/Controls/LabelListControl.xaml
index 8708748..b3db606 100644
--- a/FileManager_UWP/Controls/LabelListControl.xaml
+++ b/FileManager_UWP/Controls/LabelListControl.xaml
@@ -7,9 +7,18 @@
         <Setter Property="Template">
             <Setter.Value>
                 <ControlTemplate TargetType="local:LabelListControl">
-                    <Grid>
+                    <StackPanel>
                         <TextBlock Name="LabelTextBlock"></TextBlock>
-                    </Grid>
+                        <!--<ListView Name="LabelListView">
+                            <ListView.ItemTemplate>
+                                <DataTemplate>
+                                    <Grid>
+                                        <TextBlock Text="{Binding}"></TextBlock>
+                                    </Grid>
+                                </DataTemplate>
+                            </ListView.ItemTemplate>
+                        </ListView>-->
+                    </StackPanel>
                 </ControlTemplate>
             </Setter.Value>
         </Setter>
diff --git a/FileManager_UWP/View/TestLabelView.xaml b/FileManager_UWP/View/TestLabelView.xaml
index 27f4880..c8087c3 100644
--- a/FileManager_UWP/View/TestLabelView.xaml
+++ b/FileManager_UWP/View/TestLabelView.xaml
@@ -13,6 +13,15 @@
         <TextBlock
             FontSize="50"
             Text="Test Label View" />
-        <controls:LabelListControl></controls:LabelListControl>
+        <Button FontSize="20" Content="加" Click="Button_Click"></Button>
+        <!--<ListView ItemsSource="{x:Bind Labels}">
+            <ListView.ItemTemplate>
+                <DataTemplate>
+                    <TextBlock Text="{Binding}"></TextBlock>
+                </DataTemplate>
+            </ListView.ItemTemplate>
+        </ListView>-->
+        
+        <controls:LabelListControl ItemsSource="{x:Bind Labels}"></controls:LabelListControl>
     </StackPanel>
 </Page>
diff --git a/FileManager_UWP/View/TestLabelView.xaml.cs b/FileManager_UWP/View/TestLabelView.xaml.cs
index 2900d54..5dd6255 100644
--- a/FileManager_UWP/View/TestLabelView.xaml.cs
+++ b/FileManager_UWP/View/TestLabelView.xaml.cs
@@ -1,5 +1,7 @@
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices.WindowsRuntime;
@@ -20,8 +22,16 @@ namespace FileManager_UWP.View {
     /// An empty page that can be used on its own or navigated to within a Frame.
     /// </summary>
     public sealed partial class TestLabelView: Page {
+        public ObservableCollection<string> Labels = new ObservableCollection<string>{ "miao", "ddd" };
+
         public TestLabelView() {
             this.InitializeComponent();
+            Debug.WriteLine(Labels.ToString());
+        }
+
+        private void Button_Click(object sender, RoutedEventArgs e) {
+            Labels.Add("KKK");
+            Debug.WriteLine(Labels.Count.ToString());
         }
     }
 }