从对象列表中获取值(Get Value From Object List)

从对象列表中获取值(Get Value From Object List)

我有一个Employee对象列表

public struct Employee { public string role; public string id; public int salary; public string name; public string address; }

我想获取name和id属性与条件匹配的对象。 我试过用这个：

List<Employee> EleList = new List<Employee>(); var employee= EleList.Find(sTag => sTag.id == 5b && sTag.name== "lokendra");

这非常耗时，因为列表大小介于20000-25000之间。是否有其他方法可以检索结果。 请指导我这个。

I have a list of objects Employee

public struct Employee { public string role; public string id; public int salary; public string name; public string address; }

I want to get the object where the name and id property matches the condition. I have tried using this:

List<Employee> EleList = new List<Employee>(); var employee= EleList.Find(sTag => sTag.id == 5b && sTag.name== "lokendra");

This is pretty time consuming because the list size is between 20000-25000.Is there any other way to retrieve the result. Please guide me on this.

最满意答案

您可以使用适当的集合类型（例如字典）来加快速度。

如果Employee的id是唯一的，则可以将其用作Dictionary<string, Employee>类型的Dictionary<string, Employee>的键。 搜索看起来像这样：

Employee employee; if(dict.TryGetValue("5b", out employee) && employee.name == "lokendra") // employee found else // employee not found

创建字典将如下所示：

dict = EleList.ToDictionary(x => x.id, x => x);

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如果它不是唯一但合理集中（只有少数具有相同id的员工），则可以将其用作Dictionary<string, List<Employee>>类型Dictionary<string, List<Employee&t;>的键。 搜索看起来像这样：

Employee GetEmployee(string id, string name) { List<Employee> employees; if(!dict.TryGetValue(id, out employees)) return null; return employees.FirstOrDefault(x => x.name == name); }

创建字典将如下所示：

dict = EleList.GroupBy(x => x.id) .ToDictionary(x => x.Key, x => x.ToList());

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请注意： 在这两种情况下，您应该只创建一次字典而不是每次搜索。 所以基本上，你应该有字典而不是EleList 。

You can speed this up by using an appropriate collection type, e.g. a Dictionary.

If the id of the Employee is unique, you can use it as the key in a dictionary of type Dictionary<string, Employee>. Searching would look like this:

Employee employee; if(dict.TryGetValue("5b", out employee) && employee.name == "lokendra") // employee found else // employee not found

Creating the dictionary would look like this:

dict = EleList.ToDictionary(x => x.id, x => x);

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If it is not unique but reasonably focused (only a few employees with the same id), you can use it as a key in a dictionary of type Dictionary<string, List<Employee>>. Searching would look like this:

Employee GetEmployee(string id, string name) { List<Employee> employees; if(!dict.TryGetValue(id, out employees)) return null; return employees.FirstOrDefault(x => x.name == name); }

Creating the dictionary would look like this:

dict = EleList.GroupBy(x => x.id) .ToDictionary(x => x.Key, x => x.ToList());

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Please note: In both cases, you should create the dictionary only once and not for every search. So basically, instead of EleList you should have the dictionary.