C# Dictionary用法总结

publicstaticvoidDicSample1()

{

Dictionary<String, String> pList =newDictionary<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(varkeyinpList.Keys)

{

Console.WriteLine("Output Key: {0}", key);

}

//遍历Value

foreach(String valueinpList.Values)

{

Console.WriteLine("Output Value: {0}", value);

}

//遍历Key和Value

foreach(vardicinpList)

{

Console.WriteLine("Output Key : {0}, Value : {1} ", dic.Key, dic.Value);

}

}

/// <summary>

/// Dictionary的Value为一个数组

/// </summary>

publicstaticvoidDicSample2()

{

Dictionary<String, String[]> dic =newDictionary<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]);

}

//Dictionary的Value为一个类

publicstaticvoidDicSample3()

{

Dictionary<String, Student> stuList =newDictionary<String, Student>();

Student stu =null;

for(inti = 0; i < 3; i++ )

{

stu =newStudent();

stu.Name = i.ToString();

stu.Name ="StuName"+ i.ToString();

stuList.Add(i.ToString(), stu);

}

foreach(varstudentinstuList)

{

Console.WriteLine("Output : Key {0}, Num : {1}, Name {2}", student.Key, student.Value.Name, student.Value.Name);

}

}

publicclassStudent

{

publicString Num {get;set; }

publicString Name {get;set; }

}

/// <summary>

/// Dictionary的扩展方法使用

/// </summary>

publicstaticvoidDicSample4()

{

//1)普通调用

Dictionary<int, String> dict =newDictionary<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,outF);

Console.WriteLine("F : {0}",F);

foreach(vardicindict)

{

Console.WriteLine("Output : Key : {0}, Value : {1}", dic.Key, dic.Value);

}

//5)下面是使用GetValue获取值

varv1 = dict.GetValue(111,null);

varv2 = dict.GetValue(10,"abc");

//6)批量添加

vardict1 =newDictionary<int,int>();

dict1.AddOrPeplace(3, 3);

dict1.AddOrPeplace(5, 5);

vardict2 =newDictionary<int,int>();

dict2.AddOrPeplace(1, 1);

dict2.AddOrPeplace(4, 4);

dict2.AddRange(dict1,false);

}

publicstaticclassDictionaryExtensionMethodClass

{

/// <summary>

/// 尝试将键和值添加到字典中：如果不存在，才添加；存在，不添加也不抛导常

/// </summary>

publicstaticDictionary<TKey, TValue> TryAdd<TKey, TValue>(thisDictionary<TKey, TValue> dict, TKey key, TValue value)

{

if(dict.ContainsKey(key) ==false)

dict.Add(key, value);

returndict;

}

/// <summary>

/// 将键和值添加或替换到字典中：如果不存在，则添加；存在，则替换

/// </summary>

publicstaticDictionary<TKey, TValue> AddOrPeplace<TKey, TValue>(thisDictionary<TKey, TValue> dict, TKey key, TValue value)

{

dict[key] = value;

returndict;

}

/// <summary>

/// 获取与指定的键相关联的值，如果没有则返回输入的默认值

/// </summary>

publicstaticTValue GetValue<TKey, TValue>(thisDictionary<TKey, TValue> dict, TKey key, TValue defaultValue)

{

returndict.ContainsKey(key)?dict[key] : defaultValue;

}

/// <summary>

/// 向字典中批量添加键值对

/// </summary>

/// <param name="replaceExisted">如果已存在，是否替换</param>

publicstaticDictionary<TKey, TValue> AddRange<TKey, TValue>(thisDictionary<TKey, TValue> dict, IEnumerable<KeyValuePair<TKey, TValue>> values,boolreplaceExisted)

{

foreach(variteminvalues)

{

if(dict.ContainsKey(item.Key) ==false|| replaceExisted)

dict[item.Key] = item.Value;

}

returndict;

}

}