Question

我有一个循环运行检索实时股价。我想要做的是检查检索到的任何价格是否与我已经存储在字典中的价格不同，并通知我所有已更改的细节。正在使用INotifyCollectionChanged查看字典。

e.g。

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

namespace BasicExamples
{
    class CollectionNotify:INotifyCollectionChanged
    {
        public Dictionary<string, string> NotifyDictionary{ get; set; }     

        public CollectionNotify()
        {
            NotifyDictionary = new Dictionary<string, string>();
        }

        public event NotifyCollectionChangedEventHandler CollectionChanged;

        protected virtual void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
        {
            if (CollectionChanged != null)
            {
                CollectionChanged(this, e);
            }
        }

        public void Add(object k, object v)
        {
            NotifyDictionary.Add(k.ToString(),v.ToString());
            OnCollectionChanged(new     NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add,0));
        }

        public void Update(object k, object v)
        {
            bool isUpdated = false;
            IList<string> changedItems = new List<string>();
            int index;
            if (NotifyDictionary.ContainsKey(k.ToString()))
            {
                NotifyDictionary[k.ToString()] = v.ToString();
                changedItems.Add(k+":"+v);
                isUpdated = true;
            }
            else
            {
                Add(k, v);
            }
            if (isUpdated)
            {
                OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Replace,changedItems,changedItems));
            }                
        }
    }
}

主程序调用Add / Update作为测试。然而，当循环遍历NotifyCollectionChangedEventArgs时，我必须嵌套循环并转换为IEnumerable - 这似乎是一个非常漫长的方式。

using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace BasicExamples
{
    class Program
    {
        //delegate 
        static void Main(string[] args)
        {
            //notify collection
            CollectionNotify notify = new CollectionNotify();
            notify.CollectionChanged += CollectionHasChanged;

            notify.Add("Test1", "Test2");
            notify.Add("Test2","Test2");
            notify.Add("Test3", "Test3");
            notify.Update("Test2", "Test1");
            notify.Update("Test2", "Test3");
            notify.Update("Test3", "Test1");
            notify.Update("Test1", "Test3");

            #region Lamba

            //lamba
            List<int> myList = new List<int>() {1,1,2,3,4,5,6};

            List<int> newList = myList.FindAll(s =>
            {
                if (s == 1)
                {
                    return true;
                }
                return false;
            });

            foreach (int b in newList)
            {
                Console.WriteLine(b.ToString());
            }

            #endregion
        }

        public static void CollectionHasChanged(object sender, EventArgs e)
        {
            NotifyCollectionChangedEventArgs args = (NotifyCollectionChangedEventArgs) e;
            if (args.Action == NotifyCollectionChangedAction.Replace)
            {
                foreach (var item in args.NewItems)
                {
                    foreach (var nextItem in (IEnumerable)item)
                    {
                        Console.WriteLine(nextItem);
                    }
                }
            }
        }
    }
}

我想我的问题有两个： - 答：这是使用通知词典的最佳方式吗？ B：我应该使用上面的嵌套循环来检索更新的值吗？

提前致谢

C＃字典更改通知（INotifyCollectionChanged）

0 个答案: