请问如何判断Dictionary的TKey相等
问题如下:
Dictionary 的key 和 value 都是自定义的类型。key是一个class . 定义如下
public class HomePageChartEntity : IEquatable<HomePageChartEntity>
{
public string STimeBegin
{
get;
set;
}
public string kPIID
{
get;
set;
}
public bool Equals(HomePageChartEntity other)
{
if (
&& this.STimeBegin.Equals(other.STimeBegin)
&& this.kPIID.Equals(other.kPIID))
{
return true;
}
else
{
return false;
}
}
}
那么声明一个Dictionary ,如下代码
Dictionary<HomePageChartEntity , string> text = new Dictionary<HomePageChartEntity , string>();
往里面添加元素
text.Add(new HomePageChartEntity {STimeBegin="123456",kPIID="test123456"} , "第1个键");
text.Add(new HomePageChartEntity {STimeBegin="123456",kPIID="test123456"} , "第2个键");
text.Add(new HomePageChartEntity {STimeBegin="123456",kPIID="test123456"} , "第3个键");
理论上,是不能添加进去的,因为是相等key ,但这段代码却可以添加到字典中去。
各位看看什么问题,谢谢!
代码手打的,难免有语法错误请见谅
------解决方案-------------------- 判断key是否相同是调用了 object.GetHashcode()进行比较。
------解决方案-------------------- 你的key是一个类型,每次new一个,指针当然不一样了,怎么会错误呢
可以重写 Equal和GetHashCode,Equal用来简单判断是否相等
------解决方案-------------------- 呵呵,还要实现Object.Equals(Object)和 GetHashCode。
下面来自msdnhttp://msdn.microsoft.com/en-us/library/ms131187.aspx
If you implement IEquatable<T>, you should also override the base class implementations of Object.Equals(Object) and GetHashCode so that their behavior is consistent with that of the IEquatable<T>.Equals method.
从这篇文章里找到的线索。
http://www.haogongju.net/art/954904
------解决方案--------------------
这样就ok了,已经试过了
C# code
public class HomePageChartEntity : IEquatable<HomePageChartEntity>
{
public string STimeBegin
{
get;
set;
}
public string kPIID
{
get;
set;
}
public bool Equals(HomePageChartEntity other)
{
if (this.STimeBegin.Equals(other.STimeBegin) && this.kPIID.Equals(other.kPIID))
{
return true;
}
else
{
return false;
}
}
public override bool Equals(object obj)
{
HomePageChartEntity other = obj as HomePageChartEntity;
if (other == null)
return false;
if (this.STimeBegin.Equals(other.STimeBegin) && this.kPIID.Equals(other.kPIID))
{
return true;
}
else
{
return false;
}
}
public override int GetHashCode()
{
return (STimeBegin + kPIID).GetHashCode();
}
------解决方案-------------------- 探讨 呵呵,还要实现Object.Equals(Object)和 GetHashCode。 下面来自msdnhttp://msdn.microsoft.com/en-us/library/ms131187.aspx If you implement IEquatable<T>, you should also override the base class implementations o……