WPF Combobox绑定Dictionary / ObservableDictionary

• 一、WPFcombobox绑定dictionary
• 二、ObservableDictionary

一、WPFcombobox绑定dictionary

ViewModel中存在以下字典数据，要将其绑定到xaml的Combox中

 private Dictionary<long,string> _MusicList=
   					  new Dictionary<long, string> {
  					     { 3778678, "云音乐热歌榜" },
    					 { 2248307886, "抖音热歌" },
    					 { 3779629, "云音乐新歌榜" },
   						 { 4395559, "华语金曲榜" },
   						 { 64016, "中国TOP排行榜（内地榜）" },
  					     { 112504, "中国TOP排行榜（港台榜）" },
   						 { 19723756, "云音乐飙升榜" },
  						 { 2884035, "网易原创歌曲榜" },
 };
 public Dictionary<long,string> MusicList
 {
     get { return this._MusicList; }
     set
     {
         this._MusicList = value;
         RaisePropertyChanged(() => MusicList);
     }
 }

字典的绑定

 <ComboBox Grid.Row="1"   ItemsSource="{Binding MusicList}" 
                							 DisplayMemberPath="Value" 
                                             SelectedValuePath = "Key"></ComboBox>

二、ObservableDictionary

public class ObservableDictionary<TKey, TValue> : Dictionary<TKey, TValue>, INotifyCollectionChanged, INotifyPropertyChanged
{
    public ObservableDictionary()
        : base()
    { }
 
    private int _index;
    public event NotifyCollectionChangedEventHandler CollectionChanged;
    public event PropertyChangedEventHandler PropertyChanged;
 
    public new KeyCollection Keys
    {
        get { return base.Keys; }
    }
 
    public new ValueCollection Values
    {
        get { return base.Values; }
    }
 
    public new int Count 
    {
        get { return base.Count; }
    }
 
    public new TValue this[TKey key]
    {
        get { return this.GetValue(key); }
        set { this.SetValue(key, value); }
    }
 
    public TValue this[int index]
    {
        get { return this.GetIndexValue(index); }
        set { this.SetIndexValue(index, value); }
    }
 
    public new void Add(TKey key, TValue value)
    {
        base.Add(key, value);
        this.OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, this.FindPair(key), _index));
        OnPropertyChanged("Keys");
        OnPropertyChanged("Values");
        OnPropertyChanged("Count");
    }
 
    public new void Clear()
    {
        base.Clear();
        this.OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
        OnPropertyChanged("Keys");
        OnPropertyChanged("Values");
        OnPropertyChanged("Count");
    }
 
    public new bool Remove(TKey key)
    {
        var pair = this.FindPair(key);
        if (base.Remove(key))
        {
            this.OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, pair, _index));
            OnPropertyChanged("Keys");
            OnPropertyChanged("Values");
            OnPropertyChanged("Count");
            return true;
        }
        return false;
    }
 
    protected void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
    {
        if (this.CollectionChanged != null)
        {
            this.CollectionChanged(this, e);
        }
    }
 
    protected void OnPropertyChanged(string propertyName)
    {
        if (this.PropertyChanged != null)
        {
            this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
 
    #region private方法
    private TValue GetIndexValue(int index)
    {
        for (int i = 0; i < this.Count; i++)
        {
            if (i == index)
            {
                var pair = this.ElementAt(i);
                return pair.Value;
            }
        }
 
        return default(TValue);
    }
 
    private void SetIndexValue(int index, TValue value)
    {
        try
        {
            var pair = this.ElementAtOrDefault(index);
            SetValue(pair.Key, value);                
        }
        catch (Exception)
        {
             
        }
    }
 
    private TValue GetValue(TKey key)
    {
        if (base.ContainsKey(key))
        {
            return base[key];
        }
        else
        {
            return default(TValue);
        }
    }
 
    private void SetValue(TKey key, TValue value)
    {
        if (base.ContainsKey(key))
        {
            var pair = this.FindPair(key);
            int index = _index;
            base[key] = value;
            var newpair = this.FindPair(key);
            this.OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Replace, newpair, pair, index));
            OnPropertyChanged("Values");
            OnPropertyChanged("Item[]");
        }
        else
        {
            this.Add(key, value);
        }
    }
 
    private KeyValuePair<TKey, TValue> FindPair(TKey key)
    {
        _index = 0;
        foreach (var item in this)
        {
            if (item.Key.Equals(key))
            {
                return item;
            }
            _index++;
        }
        return default(KeyValuePair<TKey, TValue>);
    }
 
    private int IndexOf(TKey key)
    {
        int index = 0;
        foreach (var item in this)
        {
            if (item.Key.Equals(key))
            {
                return index;
            }
            index++;
 
        }
        return -1;
    }
 
    #endregion
 
}