WPF-如何使用键(如字典)实现observeCollection<K,T>?

Someone already made it . 我还没试过,但没什么可输的。

var collection = new ObservableCollection<KeyValuePair<TKey, TValue>>();

您应该能够通过以下方式解决此问题:

collection.First(x => x.Key == *your key value*)

创建实现IDictionary、INotifyCollectionChanged和INotifyPropertyChanged接口的类。该类将有一个Dictionary实例,用于实现IDictionary(下面将其中一个Add方法作为示例进行编码)。INotifyCollectionChanged和inotifyPropertyChanged都要求存在事件,这些事件应该在包装函数中的适当点激发(同样,请参阅下面的Add方法以获取示例)

class ObservableDictionary<TKey, TValue> : IDictionary, INotifyCollectionChanged, INotifyPropertyChanged
{
    private Dictionary<TKey, TValue> mDictionary;
    // Methods & Properties for IDictionary implementation would defer to mDictionary:
    public void Add(TKey key, TValue value){
        mDictionary.Add(key, value);
        OnCollectionChanged(NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, value)
        return;
    }
    // Implementation of INotifyCollectionChanged:
    public event NotifyCollectionChangedEventHandler CollectionChanged;
    protected void OnCollectionChanged(NotifyCollectionChangedEventArgs args){
        // event fire implementation
    }
    // Implementation of INotifyProperyChanged:
    public event ProperyChangedEventHandler ProperyChanged;
    protected void OnPropertyChanged(PropertyChangedEventArgs args){
        // event fire implementation
    }
}

编辑:

ICollection<KeyValuePair<TKey,TValue>>
IEnumerable<KeyValuePair<TKey,TValue>>
IEnumerable.

根据您的需要,您可能不必实现整个IDictionary接口,如果您只需要调用几个方法,那么只需实现这些方法,IDictionary接口就成了一种奢侈品。必须实现INotifyCollectionChanged和INotifyPropertyChanged接口,绑定才能工作但是,大引号

比如说:

ObservableCollection<Tuple<string, object>>()

当然,字符串、对象和示例类型

public class ObservableDictonary<TKey, TValue> : Dictionary<TKey, TValue>, INotifyCollectionChanged, INotifyPropertyChanged
{
    public event NotifyCollectionChangedEventHandler CollectionChanged;

    public event PropertyChangedEventHandler PropertyChanged;

    public new void Add(TKey key, TValue value)
    {
        base.Add(key, value);
        if (!TryGetValue(key, out _)) return;
        var index = Keys.Count;
        OnPropertyChanged(nameof(Count));
        OnPropertyChanged(nameof(Values));
        OnCollectionChanged(NotifyCollectionChangedAction.Add, value, index);
    }

    public new void Remove(TKey key)
    {
        if (!TryGetValue(key, out var value)) return;
        var index = IndexOf(Keys, key);
        OnPropertyChanged(nameof(Count));
        OnPropertyChanged(nameof(Values));
        OnCollectionChanged(NotifyCollectionChangedAction.Remove, value, index);
        base.Remove(key);
    }

    public new void Clear()
    {

    }

    protected virtual void OnPropertyChanged(PropertyChangedEventArgs e)
    {
        PropertyChanged?.Invoke(this, e);
    }

    protected virtual void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
    {
        CollectionChanged?.Invoke(this, e);
    }

    private void OnPropertyChanged(string propertyName)
    {
        OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
    }

    private void OnCollectionChanged(NotifyCollectionChangedAction action, object item)
    {
        OnCollectionChanged(new NotifyCollectionChangedEventArgs(action, item));
    }

    private void OnCollectionChanged(NotifyCollectionChangedAction action, object item, int index)
    {
        OnCollectionChanged(new NotifyCollectionChangedEventArgs(action, item, index));
    }

    private int IndexOf(KeyCollection keys, TKey key)
    {
        var index = 0;
        foreach (var k in keys)
        {
            if (Equals(k, key))
                return index;
            index++;
        }
        return -1;
    }
}