我有以下Application
类型的对象的列表,如下所示:
public class Application
{
public int AppId { get; set; }
public List<Question> Questions { get; set; }
}
我想要做的是将它们映射为Section
类型的对象,如下所示:
public class Section
{
public List<int> AppIds { get; set; }
public List<Question> Questions { get; set; }
}
通过按照以下规则将它们分组:在包含这些问题的AppId列表下收集所有相同的问题。示例输入和输出:
Input: A1(Q1,Q2,Q3), A2(Q1,Q2), A3(Q1,Q3), A4(Q1).
Output: A1,A2,A3,A4(Q1), A1,A2(Q2), A1,A3(Q3)
有可能在LINQ中做到吗?还是我必须自己编写逻辑?
答案 0 :(得分:1)
也许有一种更简单的方法,但这是我编写的第一个LINQ
查询,至少应该足以使您入门。首先,我将您的问题和appid弄平,然后按问题重新分组,然后按问题列出您的appid。请注意,在运行之前,您必须填充List
个应用程序。
List<Application> app = new List<Application>();
var output = (from a in app.SelectMany(p => p.Questions.Select(z => new {z, p.AppId})
group a.AppId by new
{
a.Questions
} into combined
select new
{
combined.Key.Questions,
combined.ToList()
});
答案 1 :(得分:0)
我认为这个问题被略微描述了。每个应用程序应具有不同的AppId
,因此基本上没有任何分组依据,因为所有AppId
都不同。相反,我们应该按问题分组,因为每个应用程序都可能有相同的问题。
这就是我所拥有的(就样式而言,它与确切的输出不匹配,因为您的示例输出基于AppId
的分组而不是问题,但预期结果是相同的):
using System;
using System.Collections.Generic;
using System.Linq;
public class Program
{
public static void Main()
{
// create Questions
var questionOne = new Question(){QuestionId = 1, ActualQuestion = "Who"};
var questionTwo = new Question(){QuestionId = 2, ActualQuestion = "What"};
var questionThree = new Question(){QuestionId = 3, ActualQuestion = "Where"};
// Assign questions to the specified list of questions
var applicationOneQuestions = new List<Question>(){questionOne, questionTwo, questionThree};
var applicationTwoQuestions = new List<Question>() {questionOne, questionTwo};
var applicationThreeQuestions = new List<Question>() {questionOne, questionThree};
var applicationFourQuestions = new List<Question>() {questionOne};
// Create Applications
var applicationOne = new Application(){AppId = 1, Questions = applicationOneQuestions};
var applicationTwo = new Application(){AppId = 2, Questions = applicationTwoQuestions};
var applicationThree = new Application() {AppId = 3, Questions = applicationThreeQuestions};
var applicationFour = new Application() {AppId = 4, Questions = applicationFourQuestions};
// Create List of Applications
var lstApplications = new List<Application>(){applicationOne, applicationTwo, applicationThree, applicationFour};
// Group Applications based on Questions and cast to Section Object
var groupApplications = lstApplications.GroupBy(x => x.Questions).Select(t => new Section { AppIds = t.Select(z => z.AppId).ToList() , Questions = t.Key}).ToList();
foreach(var item in groupApplications)
{
foreach(var appId in item.AppIds)
{
Console.WriteLine(appId);
}
foreach(var question in item.Questions)
{
Console.WriteLine(question.ActualQuestion);
}
Console.WriteLine("\n");
}
}
}
public class Application
{
public int AppId { get; set; }
public List<Question> Questions { get; set; }
}
public class Section
{
public List<int> AppIds { get; set; }
public List<Question> Questions { get; set; }
}
public class Question
{
public int QuestionId {get;set;}
public string ActualQuestion {get;set;}
}
输出
// 1
// Who
// What
// Where
// 2
// Who
// What
// 3
// Who
// Where
// 4
// Who
应用程序1、2、3、4都包含一个问题
应用程序1、2包含第二个问题
应用程序1、3包含问题3
请告诉我这是否有帮助。我也为您创建了一个DotNetFiddle,供您自己进行测试并提供反馈。