work hard work smart 原文 C# Dictionary用法总结
1、常规用法
增加键值对之前需要判断是否存在该键，如果已经存在该键而且不判断，将抛出异常。所以这样每次都要进行判断，很麻烦，在备注里使用了一个扩展方法
public static void DicSample1() { Dictionary<String, String> pList = new Dictionary<String, String>(); try { if (pList.ContainsKey("Item1") == false) { pList.Add("Item1", "ZheJiang"); } if (pList.ContainsKey("Item2")== false) { pList.Add("Item2", "ShangHai"); } else { pList["Item2"] = "ShangHai"; } if (pList.ContainsKey("Item3") == false) { pList.Add("Item3", "BeiJiang"); } } catch (System.Exception e) { Console.WriteLine("Error: {0}", e.Message); } //判断是否存在相应的key并显示 if (pList.ContainsKey("Item1")) { Console.WriteLine("Output: " + pList["Item1"]); } //遍历Key foreach (var key in pList.Keys) { Console.WriteLine("Output Key: {0}", key); } //遍历Value foreach (String value in pList.Values) { Console.WriteLine("Output Value: {0}", value); } //遍历Key和Value foreach (var dic in pList) { Console.WriteLine("Output Key : {0}, Value : {1} ", dic.Key, dic.Value); } }
2、Dictionary的Value为一个数组
/// <summary> /// Dictionary的Value为一个数组 /// </summary> public static void DicSample2() { Dictionary<String, String[]> dic = new Dictionary<String, String[]>(); String[] ZheJiang = { "Huzhou", "HangZhou", "TaiZhou" }; String[] ShangHai = { "Budong", "Buxi" }; dic.Add("ZJ", ZheJiang); dic.Add("SH", ShangHai); Console.WriteLine("Output :" + dic["ZJ"][0]); }
3、Dictionary的Value为一个类
//Dictionary的Value为一个类 public static void DicSample3() { Dictionary<String, Student> stuList = new Dictionary<String, Student>(); Student stu = null; for (int i = 0; i < 3; i++ ) { stu = new Student(); stu.Name = i.ToString(); stu.Name = "StuName" + i.ToString(); stuList.Add(i.ToString(), stu); } foreach (var student in stuList) { Console.WriteLine("Output : Key {0}, Num : {1}, Name {2}", student.Key, student.Value.Name, student.Value.Name); } }
Student类：
public class Student { public String Num { get; set; } public String Name { get; set; } }
4 扩展方法
/// <summary> /// Dictionary的扩展方法使用 /// </summary> public static void DicSample4() { //1)普通调用 Dictionary<int, String> dict = new Dictionary<int, String>(); DictionaryExtensionMethodClass.TryAdd(dict, 1, "ZhangSan"); DictionaryExtensionMethodClass.TryAdd(dict, 2, "WangWu"); DictionaryExtensionMethodClass.AddOrPeplace(dict, 3, "WangWu"); DictionaryExtensionMethodClass.AddOrPeplace(dict, 3, "ZhangWu"); DictionaryExtensionMethodClass.TryAdd(dict, 2, "LiSi"); //2)TryAdd 和 AddOrReplace 这两个方法具有较强自我描述能力，用起来很省心，而且也简单： dict.AddOrPeplace(20, "Orange"); dict.TryAdd(21, "Banana"); dict.TryAdd(22, "apple"); //3)像Linq或jQuery一样连起来写 dict.TryAdd(10, "Bob") .TryAdd(11, "Tom") .AddOrPeplace(12, "Jom"); //4) 获取值 String F = "Ba"; dict.TryGetValue(31, out F); Console.WriteLine("F : {0}",F); foreach (var dic in dict) { Console.WriteLine("Output : Key : {0}, Value : {1}", dic.Key, dic.Value); } //5)下面是使用GetValue获取值 var v1 = dict.GetValue(111,null); var v2 = dict.GetValue(10,"abc"); //6)批量添加 var dict1 = new Dictionary<int,int>(); dict1.AddOrPeplace(3, 3); dict1.AddOrPeplace(5, 5); var dict2 = new Dictionary<int, int>(); dict2.AddOrPeplace(1, 1); dict2.AddOrPeplace(4, 4); dict2.AddRange(dict1, false); }
扩展方法所在的类
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本文转自wenglabs博客园博客，原文链接：http://www.cnblogs.com/arxive/p/5950628.html
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