ObservableDictionary触发ArgumentOutOfRangeException [重复]

问题描述 投票:0回答:2

为了将字典绑定到列表框,我使用了已由某人实现的observable dictionary

当我在Dic[0] = "three";之前初始化System.ArgumentOutOfRangeException时,[ObservableDictionary抛出InitializeComponent()

OnCollectionChanged(NotifyCollectionChangedAction.Replace, new KeyValuePair<TKey, TValue>(key, value), new KeyValuePair<TKey, TValue>(key, item));替换OnCollectionChanged();(在ObservableDictionary之前初始化InitializeComponent()的情况下]

似乎可以解决异常问题。这是一个好的解决方案吗?

TestWindow.xaml

<Window x:Class="Wpf.TestWindow" x:Name="win"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    DataContext="{Binding ElementName=win}"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d" Title="TestWindow" Height="450" Width="800">

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="auto"/>
        <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>

    <StackPanel Orientation="Vertical">
        <ListBox MinHeight="100" MinWidth="100"
            DataContext="{Binding ElementName=win}"
            ItemsSource="{Binding Path=Dic}"
            SelectedValuePath="Key"                         
            DisplayMemberPath="Value"/>
        <Button Content="modify" MinWidth="100" Click="Button_Click"/>
    </StackPanel>
</Grid>

TestWindow.cs

using System.Collections.ObjectModel;
using System.Windows;    
namespace Wpf
{   
    public partial class TestWindow : Window, INotifyPropertyChanged
    {
        private ObservableDictionary<int, string> dic;
        public ObservableDictionary<int, string> Dic {
            get => dic;
            set
            {
                dic = value;
                PropertyChanged(this, new PropertyChangedEventArgs(nameof(Dic)));
            }
        }

        public TestWindow()
        {
            InitializeComponent();
            Dic = new ObservableDictionary<int, string>() { {0,"Zero" }, {1, "one" }, };
            Dic.Add(2, "two");    
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            Dic[0] = "three";
            Dic.Remove(1);
        }
    }
}

ObservableDictionary.cs

using System.Linq;
using System.ComponentModel;
using System.Collections.Generic;
using System.Collections.Specialized;

namespace System.Collections.ObjectModel
{
    public class ObservableDictionary<TKey, TValue> : IDictionary<TKey, TValue>, INotifyCollectionChanged, INotifyPropertyChanged
    {
        private const string CountString = "Count";
        private const string IndexerName = "Item[]";
        private const string KeysName = "Keys";
        private const string ValuesName = "Values";

        private IDictionary<TKey, TValue> _Dictionary;
        protected IDictionary<TKey, TValue> Dictionary
        {
            get { return _Dictionary; }
        }

        #region Constructors
        public ObservableDictionary()
        {
            _Dictionary = new Dictionary<TKey, TValue>();
        }
        public ObservableDictionary(IDictionary<TKey, TValue> dictionary)
        {
            _Dictionary = new Dictionary<TKey, TValue>(dictionary);
        }
        public ObservableDictionary(IEqualityComparer<TKey> comparer)
        {
            _Dictionary = new Dictionary<TKey, TValue>(comparer);
        }
        public ObservableDictionary(int capacity)
        {
            _Dictionary = new Dictionary<TKey, TValue>(capacity);
        }
        public ObservableDictionary(IDictionary<TKey, TValue> dictionary, IEqualityComparer<TKey> comparer)
        {
            _Dictionary = new Dictionary<TKey, TValue>(dictionary, comparer);
        }
        public ObservableDictionary(int capacity, IEqualityComparer<TKey> comparer)
        {
            _Dictionary = new Dictionary<TKey, TValue>(capacity, comparer);
        }
        #endregion

        #region IDictionary<TKey,TValue> Members

        public void Add(TKey key, TValue value)
        {
            Insert(key, value, true);
        }

        public bool ContainsKey(TKey key)
        {
            return Dictionary.ContainsKey(key);
        }

        public ICollection<TKey> Keys
        {
            get { return Dictionary.Keys; }
        }

        public bool Remove(TKey key)
        {
            if (key == null) throw new ArgumentNullException("key");

            TValue value;
            Dictionary.TryGetValue(key, out value);
            var removed = Dictionary.Remove(key);
            if (removed)
                //OnCollectionChanged(NotifyCollectionChangedAction.Remove, new KeyValuePair<TKey, TValue>(key, value));
                OnCollectionChanged();    
            return removed;
        }    

        public bool TryGetValue(TKey key, out TValue value)
        {
            return Dictionary.TryGetValue(key, out value);
        }


        public ICollection<TValue> Values
        {
            get { return Dictionary.Values; }
        }


        public TValue this[TKey key]
        {
            get
            {
                return Dictionary[key];
            }
            set
            {
                Insert(key, value, false);
            }
        }


        #endregion


        #region ICollection<KeyValuePair<TKey,TValue>> Members

        public void Add(KeyValuePair<TKey, TValue> item)
        {
            Insert(item.Key, item.Value, true);
        }

        public void Clear()
        {
            if (Dictionary.Count > 0)
            {
                Dictionary.Clear();
                OnCollectionChanged();
            }
        }

        public bool Contains(KeyValuePair<TKey, TValue> item)
        {
            return Dictionary.Contains(item);
        }


        public void CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
        {
            Dictionary.CopyTo(array, arrayIndex);
        }


        public int Count
        {
            get { return Dictionary.Count; }
        }


        public bool IsReadOnly
        {
            get { return Dictionary.IsReadOnly; }
        }


        public bool Remove(KeyValuePair<TKey, TValue> item)
        {
            return Remove(item.Key);
        }


        #endregion


        #region IEnumerable<KeyValuePair<TKey,TValue>> Members


        public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
        {
            return Dictionary.GetEnumerator();
        }


        #endregion


        #region IEnumerable Members


        IEnumerator IEnumerable.GetEnumerator()
        {
            return ((IEnumerable)Dictionary).GetEnumerator();
        }


        #endregion


        #region INotifyCollectionChanged Members


        public event NotifyCollectionChangedEventHandler CollectionChanged;


        #endregion


        #region INotifyPropertyChanged Members


        public event PropertyChangedEventHandler PropertyChanged;


        #endregion


        public void AddRange(IDictionary<TKey, TValue> items)
        {
            if (items == null) throw new ArgumentNullException("items");


            if (items.Count > 0)
            {
                if (Dictionary.Count > 0)
                {
                    if (items.Keys.Any((k) => Dictionary.ContainsKey(k)))
                        throw new ArgumentException("An item with the same key has already been added.");
                    else
                        foreach (var item in items) Dictionary.Add(item);
                }
                else
                    _Dictionary = new Dictionary<TKey, TValue>(items);


                OnCollectionChanged(NotifyCollectionChangedAction.Add, items.ToArray());
            }
        }


        private void Insert(TKey key, TValue value, bool add)
        {
            if (key == null) throw new ArgumentNullException("key");


            TValue item;
            if (Dictionary.TryGetValue(key, out item))
            {
                if (add) throw new ArgumentException("An item with the same key has already been added.");
                if (Equals(item, value)) return;
                Dictionary[key] = value;

                //OnCollectionChanged();
                OnCollectionChanged(NotifyCollectionChangedAction.Replace, new KeyValuePair<TKey, TValue>(key, value), new KeyValuePair<TKey, TValue>(key, item));
            }
            else
            {
                Dictionary[key] = value;

                OnCollectionChanged(NotifyCollectionChangedAction.Add, new KeyValuePair<TKey, TValue>(key, value));
            }
        }


        private void OnPropertyChanged()
        {
            OnPropertyChanged(CountString);
            OnPropertyChanged(IndexerName);
            OnPropertyChanged(KeysName);
            OnPropertyChanged(ValuesName);
        }


        protected virtual void OnPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }


        private void OnCollectionChanged()
        {
            OnPropertyChanged();
            if (CollectionChanged != null) CollectionChanged(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
        }


        private void OnCollectionChanged(NotifyCollectionChangedAction action, KeyValuePair<TKey, TValue> changedItem)
        {
            OnPropertyChanged();
            if (CollectionChanged != null) CollectionChanged(this, new NotifyCollectionChangedEventArgs(action, changedItem));
        }


        private void OnCollectionChanged(NotifyCollectionChangedAction action, KeyValuePair<TKey, TValue> newItem, KeyValuePair<TKey, TValue> oldItem)
        {
            OnPropertyChanged();
            if (CollectionChanged != null) CollectionChanged(this, new NotifyCollectionChangedEventArgs(action, newItem, oldItem));
        }


        private void OnCollectionChanged(NotifyCollectionChangedAction action, IList newItems)
        {
            OnPropertyChanged();
            if (CollectionChanged != null) CollectionChanged(this, new NotifyCollectionChangedEventArgs(action, newItems));
        }
    }
}
c# wpf xaml dictionary observable
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