这个主要是用来总结有关Dictionary添加元素的方法
第一种：简单用法
Dictionary<string, int> 或者 Dictionary<string, string>
第一步：我首先定义了一个类：DictiaonaryTest，然后在类中定义了一个全局变量，接下来完成如下功能测试
1、元素的添加
2、遍历字典中的key值并输出
3、遍历字典中的val值并输出
4、遍历字典，遍历字典，并将key值和val值都输出
public class DictiaonaryTest
{
//定义全局变量 并初始化字典
Dictionary<string, int> dic = new Dictionary<string, int>()
{
{"C#", 2 },
{"VB", 1 },
{"C", 0 },
{"C++", -1}
};
#region 01 常规用法 添加元素
/// <summary>
/// 为字典添加元素
/// </summary>
public void TestDicAdd()
{
Dictionary<string, int> dicSample = new Dictionary<string, int>();
dicSample.Add("C#", 2);
dicSample.Add("VB", 1);
dicSample.Add("C", 0);
dicSample.Add("C++", -1);
// 判断是否存在相应的key并显示 key对应的值
if (dicSample.ContainsKey("C#"))
{
int p = dicSample["C#"];
MessageBox.Show(p.ToString());
}
}
/// <summary>
/// 遍历字典中的key
/// </summary>
public void TestDicEachKey()
{
int i = 0;
string str = string.Empty;
foreach (var dickey in dic.Keys)
{
str += "key" + i + ":" + dickey + "
";
i++;
}
MessageBox.Show(str);
}
/// <summary>
/// 遍历字典中的val
/// </summary>
public void TestDicEachValue()
{
int i = 0;
string str = string.Empty;
foreach (var dicVal in dic.Values)
{
str += "val" + i + ":" + dicVal + "
";
i++;
}
MessageBox.Show(str);
}
public void TestDicEach()
{
int i = 0;
string str = string.Empty;
foreach (var dicitem in dic)
{
str += "key" + i + ":" + dicitem.Key + " " + "val" + i + ":" + dicitem.Value + "
";
i++;
}
MessageBox.Show(str);
}
#endregion
}
第二种： Dictionary的Value为一个数组
Dictionary<String, String[]> dicArr = new Dictionary<String, String[]>()
{
{ "浙江",new string[] {"Huzhou", "HangZhou", "TaiZhou"}},
{ "上海",new string[] { "Budong", "Buxi" }}
};
public void TestDicArrEach()
{
int i = 0;
string str = string.Empty;
foreach (var dicitem in dicArr)
{
str += "key" + i + ":" + dicitem.Key + " " + "val" + i + ":";
foreach (var item in dicitem.Value)
{
str += item + "
";
}
i++;
}
MessageBox.Show(str);
}
第三种：value 是个对象
Dictionary<int, Dog> dicObj = new Dictionary<int, Dog>()
{
{ 1,new Dog() { DogId = 1, DogName = "小白", DogAge = 10, DogToy = "小球"}},
{ 2,new Dog() { DogId = 2, DogName = "小黑", DogAge = 20, DogToy = "狗骨头" }},
{ 3,new Dog() { DogId = 3, DogName = "小花", DogAge = 30, DogToy = "小球"}}
};
public void TestDiffMethod()
{
Console.WriteLine("添加");
dicObj.TryAdd(4, new Dog() { DogId = 4, DogName = "老妖精", DogAge = 40, DogToy = "篮球" }); //此处写了一个扩展方法
dicObj.ForeachEx();
Console.WriteLine("添加Or替换1");
dicObj.AddOrReplace(2, new Dog() { DogId = 2, DogName = "小熊", DogAge = 20, DogToy = "蜂蜜" }); //此处写了一个扩展方法
dicObj.ForeachEx();
Console.WriteLine("添加Or替换2");
dicObj.AddOrReplace(5, new Dog() { DogId = 2, DogName = "小熊", DogAge = 20, DogToy = "蜂蜜" });
dicObj.ForeachEx();
Console.WriteLine("根据键值获取某个值：");
Dog d = dicObj.GetValByKey(5, new Dog() { });
Console.WriteLine(d.ToString());
Console.WriteLine("批量添加：");
Dictionary<int, Dog> dicObj2 = new Dictionary<int, Dog>()
{
{ 3,new Dog() { DogId = 1, DogName = "小白", DogAge = 10, DogToy = "小球"}},
{ 4,new Dog() { DogId = 2, DogName = "小黑", DogAge = 20, DogToy = "狗骨头" }},
{ 5,new Dog() { DogId = 3, DogName = "小花", DogAge = 30, DogToy = "小球"}}
};
dicObj.AddBatch(dicObj2, false);
dicObj.ForeachEx();
}
写了一个类用来扩展类：DictionaryExtend
public static class DictionaryExtend
{
/// <summary>
/// 向字典中添加元素
/// </summary>
/// <typeparam name="TKey">key类型</typeparam>
/// <typeparam name="TVal">val类型</typeparam>
/// <param name="dic"></param>
/// <param name="key">key</param>
/// <param name="val">val</param>
/// <returns></returns>
public static Dictionary<TKey, TVal> TryAdd<TKey, TVal>(this Dictionary<TKey, TVal> dic, TKey key, TVal val)
{
if (!dic.ContainsKey(key))
{
dic.Add(key, val);
}
return dic;
}
/// <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>
public static Dictionary<TKey, TVal> AddOrReplace<TKey, TVal>(this Dictionary<TKey, TVal> dict, TKey key, TVal value)
{
dict[key] = value;
return dict;
}
/// <summary>
/// 根据key值获取key对应的val值
/// </summary>
/// <typeparam name="TKey"></typeparam>
/// <typeparam name="TVal"></typeparam>
/// <param name="dic"></param>
/// <param name="key"></param>
/// <param name="defaultValue"></param>
/// <returns></returns>
public static TVal GetValByKey<TKey, TVal>(this Dictionary<TKey, TVal> dic, TKey key, TVal defaultValue)
{
return dic.ContainsKey(key) ? dic[key] : defaultValue;
}
/// <summary>
/// 向字典中批量添加键值对
/// </summary>
/// <typeparam name="TKey"></typeparam>
/// <typeparam name="TVal"></typeparam>
/// <param name="dic"></param>
/// <param name="diclist"></param>
/// <param name="replaceExisted">如果已存在，是否替换</param>
/// <returns></returns>
public static Dictionary<TKey, TVal> AddBatch<TKey, TVal>(this Dictionary<TKey, TVal> dic, Dictionary<TKey, TVal> diclist, bool replaceExisted = false)
{
foreach (var item in diclist)
{
if (!dic.ContainsKey(item.Key) || replaceExisted)
{
dic[item.Key] = item.Value;
}
}
return dic;
}
public static void ForeachEx<Int, TVal>(this Dictionary<Int, TVal> dic)
{
int i = 0;
string str = string.Empty;
if (dic.Count > 0)
{
foreach (var item in dic)
{
str += "key" + i + ":" + item.Key + " Val" + i + ":" + item.Value.ToString() + "
";
i++;
}
}
Console.WriteLine(str);
}
}