C# Dictionary根据key正序倒序排列的几种方法（亲测）

末蓝、 2022-05-30 10:05 846阅读 0赞

因在数据处理时候的不同数据类型下方便操作，所以我把几种方法都列出来。  
【同一个命名空间下的不同方法调用：命名空间名.类名.方法名】

class Program
        {
            static void Main(string[] args)
            {
                Dictionary<string, string> dic = new Dictionary<string, string>();
                dic.Add("aname", "bjson");
                dic.Add("url", "http://www.bejson.com");
                dic.Add("address", "江苏苏州科技园路");
                dic.Add("country", "中国");
    
                #region 升序方法1
                //升序方法1：
                Dictionary<string, string> ascdic = dic.OrderBy(o => o.Key).ToDictionary(o => o.Key, p => p.Value.ToString());//对key进行升序
                //遍历元素
                foreach (KeyValuePair<string, string> kv in ascdic)
                {
                    Console.WriteLine("方法一升序以后的key列表为：" + kv.Key + ", value为：" + kv.Value);
                }
                #endregion
    
                #region 升序方法2：直接使用SortedDictionary
                //升序方法2：直接使用SortedDictionary
                SortedDictionary<string, string> sorDic = new SortedDictionary<string, string>();
                sorDic.Add("street", "学院路");
                sorDic.Add("city", "上海");
                sorDic.Add("cab", "30");
                sorDic.Add("url", "http://www.google.com");
                //遍历元素
                foreach (KeyValuePair<string, string> kv in sorDic)
                {
                    Console.WriteLine("方法2的升序以后顺序为key：" + kv.Key + ", value为：" + kv.Value);
                }
                #endregion
    
                #region 升序方法3
                //升序排序方法2的简单版本
                SortedDictionary<string, string> sac = new SortedDictionary<string, string>(dic);
                foreach (KeyValuePair<string, string> kv in sorDic)
                {
                    Console.WriteLine("方法2的另一个版本以后顺序为key：" + kv.Key + ", value为：" + kv.Value);
                }
                #endregion
    
                #region 升序方法4
                //升序方法3
                ArrayList arrayList = new ArrayList();
                arrayList.AddRange(dic.Keys);
                arrayList.Sort();
    
                //遍历元素
                StringBuilder sbu = new StringBuilder();
                Dictionary<string, string> ascDic = new Dictionary<string, string>();
                foreach (string al in arrayList)//注意arrayList与al的数据类型是子集关系
                {
                    sbu.Append(al).Append(dic[al]);//得到数据为key1value1key2value2
                    ascDic.Add(al, dic[al]);
    
                }
                foreach (KeyValuePair<string, string> kv in ascDic)
                {
                    Console.WriteLine("方法3的数据封装以后顺序为key：" + kv.Key + ", value为：" + kv.Value);
                }
                Console.WriteLine("方法3升序以后的顺序为：" + sbu);
    
                #endregion
    
                //降序排列
                Console.WriteLine("---------------------降序排列结果如下：---------------------");
    
                #region 降序方法1
                //降序方法一：
                Dictionary<string, string> desDic = dic.OrderByDescending(o => o.Key).ToDictionary(o => o.Key, p => p.Value.ToString());
                foreach (KeyValuePair<string, string> kv in desDic)
                {
                    Console.WriteLine("第一种降序方式运行结果key为：" + kv.Key + ", value为" + kv.Value);
                }
                #endregion
    
                #region 降序方法三
                //降序方法二：
                Dictionary<string, string> des2Dic = new Dictionary<string, string>();
                foreach (KeyValuePair<string, string> kv in sorDic.Reverse())//Reverse()方法为反转元素顺序
                {
                    des2Dic.Add(kv.Key, kv.Value);
                    Console.WriteLine("将SortedDictionary<string, string>升序以后的数据进行降序的key为：" + kv.Key + ", value为：" + kv.Value);
                }
                #endregion
    
                #region 降序方法三
                //降序方法三：
                arrayList.Reverse();
                StringBuilder sub = new StringBuilder();
                Dictionary<string, string> desrDic = new Dictionary<string, string>();
                foreach (string al in arrayList)//注意arrayList与al的数据类型是子集关系
                {
                    sub.Append(al).Append(dic[al]);//得到数据为key1value1key2value2
                    desrDic.Add(al, dic[al]);
    
                }
                foreach (KeyValuePair<string, string> kv in desrDic)
                {
                    Console.WriteLine("方法3的ArrayList逆序以后顺序为key：" + kv.Key + ", value为：" + kv.Value);
                }
                Console.WriteLine("方法3降序以后的顺序为：" + sub);
    
                #endregion
    
    
            }
        }

运行结果：  
![这里写图片描述][70]

[70]: /images/20220530/e73869965a224ee3a2df15867ec6657e.png