C#Dictionary复制克隆副本及比较是否相等

一、复制克隆      

用等号直接Dictionary1 = Dictionary2，复制过去的是地址（赋址），这时改变Dictionary2，Dictionary1也会被改变。普遍的是我们常常在改变复制后的值时不希望改变原有的值。这时就需要赋值而不是赋址。可用下列方法进行赋值：

private void Test()
{
    Dictionary<string, string> dic = new Dictionary<string, string> { { "A", "a" }, { "B", "b" } };
    //方法一
    Dictionary<string, string> dic1 = new Dictionary<string, string>(dic);
    //方法二
    Dictionary<string, string> dic2 = Clone(dic) as Dictionary<string, string>;
    //方法三 --需要引用Newtonsoft.Json.dll
    Dictionary<string, string> dic3 = JsonConvert.DeserializeObject<Dictionary<string, string>>(JsonConvert.SerializeObject(dic2));
}

采用序列化和反序列化 

/// <summary>
/// 得到一个对象的克隆(二进制的序列化和反序列化)--需要标记可序列化
/// </summary>
public static object Clone(object obj)
{
    MemoryStream memoryStream = new MemoryStream();
    BinaryFormatter formatter = new BinaryFormatter();
    formatter.Serialize(memoryStream, obj);
    memoryStream.Position = 0;
    return formatter.Deserialize(memoryStream);
}

当值为引用类型时

[Serializable]
public class People : IEquatable<People>
{
    public string Name { get; set; }
    public int Age { get; set; }
    public bool Equals(People other)
    {
        if (other is null)
            return false;

        return this.Name == other.Name && this.Age == other.Age;
    }
}

private void Test()
{
    Dictionary<string, People> dic = new Dictionary<string, People> { { "A", new People {Name="SD",Age=0 } }, { "B", new People { Name = "FD", Age = 1 } } };
    //方法一
    Dictionary<string, People> dic2 = Clone(dic) as Dictionary<string, People>;
    //方法二 --需要引用Newtonsoft.Json.dll
    Dictionary<string, People> dic3 = JsonConvert.DeserializeObject<Dictionary<string, People>>(JsonConvert.SerializeObject(dic2));
}

二、比较两个Dictionary是否相等

/// <summary>
/// 比较
/// </summary>
private void Test()
{
    Dictionary<string, object> dic = new Dictionary<string, object> { { "A", 1 }, { "B", "b" } };
    Dictionary<string, object> dic2 = new Dictionary<string, object> { { "A", 1 }, { "B", "b" } };
    var a = dic.Equals(dic2);   //结果 false
    var b = dic.SequenceEqual(dic2);  //结果 true
}