C# 使用lambda表达式查找两个列表之间的公共元素
我有以下两个清单:C# 使用lambda表达式查找两个列表之间的公共元素,c#,linq,lambda,C#,Linq,Lambda,我有以下两个清单: var firstList = new List<ProgramInfo> () { new ProgramInfo {Name = "A", ProgramId = 1, Description = "some text1"}, new ProgramInfo {Name = "C", ProgramId = 2, Description = "some text2"}, new ProgramInfo {Name = "D", Prog
var firstList = new List<ProgramInfo> ()
{
new ProgramInfo {Name = "A", ProgramId = 1, Description = "some text1"},
new ProgramInfo {Name = "C", ProgramId = 2, Description = "some text2"},
new ProgramInfo {Name = "D", ProgramId = 3, Description = "some text3"},
new ProgramInfo {Name = "E", ProgramId = 4, Description = "some text4"}
};
var secondList = new List<ProgramInfo> ()
{
new ProgramInfo {Name = "C", ProgramId = 2, Description = "some text1"},
new ProgramInfo {Name = "D", ProgramId = 3, Description = "some text2"},
};
var firstList=新列表()
{
新程序信息{Name=“A”,ProgramId=1,Description=“some text1”},
新程序信息{Name=“C”,ProgramId=2,Description=“some text2”},
新程序信息{Name=“D”,ProgramId=3,Description=“some text3”},
新程序信息{Name=“E”,ProgramId=4,Description=“some text4”}
};
var secondList=新列表()
{
新程序信息{Name=“C”,ProgramId=2,Description=“some text1”},
新程序信息{Name=“D”,ProgramId=3,Description=“some text2”},
};
这两个列表是在运行时生成的,我必须根据这两个列表中的程序id选择公共ProgramInfo
例如,在上述示例中,输出应为
var thirdList = new List<ProgramInfo>()
{
new ProgramInfo {Name = "C", ProgramId = 2, Description = "some text1"},
new ProgramInfo {Name = "D", ProgramId = 3, Description = "some text2"},
};
public class ProgramInfo
{
public string Name { get; set; }
public int ProgramId { get; set; }
public string Description { get; set; }
}
var thirdList=新列表()
{
新程序信息{Name=“C”,ProgramId=2,Description=“some text1”},
新程序信息{Name=“D”,ProgramId=3,Description=“some text2”},
};
公共类程序信息
{
公共字符串名称{get;set;}
公共int程序ID{get;set;}
公共字符串说明{get;set;}
}
有人能建议我如何使用lambda表达式来执行此操作吗?使用Linq
.Intersect
。为此,您的类需要重写Equals
和GetHashCode
var thirdList = firstList.Intersect(secondList);
您还可以指定一个IEqualityComparer
,而不是覆盖函数:
public class Comparer : IEqualityComparer<ProgramInfo>
{
public bool Equals(ProgramInfo x, ProgramInfo y)
{
return x.Name == y.Name &&
x.ProgramId == y.ProgramId &&
x.Description == y.Description;
}
public int GetHashCode(ProgramInfo obj)
{
return obj.Name.GetHashCode() ^
obj.ProgramId.GetHashCode() ^
obj.Description.GetHashCode();
}
}
var thirdList = firstList.Intersect(secondList, new Comparer());
公共类比较器:IEqualityComparer
{
公共布尔等于(ProgramInfo x,ProgramInfo y)
{
返回x.Name==y.Name&&
x、 ProgramId==y.ProgramId&&
x、 描述==y.描述;
}
公共int GetHashCode(ProgramInfo obj)
{
返回obj.Name.GetHashCode()^
obj.ProgramId.GetHashCode()^
obj.Description.GetHashCode();
}
}
var thirdList=firstList.Intersect(secondList,new Comparer());
使用Linq.Intersect
。为此,您的类需要重写Equals
和GetHashCode
var thirdList = firstList.Intersect(secondList);
您还可以指定一个IEqualityComparer
,而不是覆盖函数:
public class Comparer : IEqualityComparer<ProgramInfo>
{
public bool Equals(ProgramInfo x, ProgramInfo y)
{
return x.Name == y.Name &&
x.ProgramId == y.ProgramId &&
x.Description == y.Description;
}
public int GetHashCode(ProgramInfo obj)
{
return obj.Name.GetHashCode() ^
obj.ProgramId.GetHashCode() ^
obj.Description.GetHashCode();
}
}
var thirdList = firstList.Intersect(secondList, new Comparer());
公共类比较器:IEqualityComparer
{
公共布尔等于(ProgramInfo x,ProgramInfo y)
{
返回x.Name==y.Name&&
x、 ProgramId==y.ProgramId&&
x、 描述==y.描述;
}
公共int GetHashCode(ProgramInfo obj)
{
返回obj.Name.GetHashCode()^
obj.ProgramId.GetHashCode()^
obj.Description.GetHashCode();
}
}
var thirdList=firstList.Intersect(secondList,new Comparer());
这可能是一个输入错误,但不确定-我是说第二个列表
和第三个列表
你是说“一些文本2”
和“一些文本3”
就像上面的列表一样?我不确定我在这里看到了多少研究成果…这可能是一个输入错误,但不确定-我是说第二个列表
和第三个列表
你是指“一些TeT2”/代码>和<代码>一些TeX3“<代码>类似于上面的列表吗?我不确定我在这里看到了很多研究工作……@ App-酷:如果你发现这有帮助,请考虑标记为解决和投票:)@ APP -酷:如果你发现这有帮助,请考虑标记为解决和投票: