使用linq将对象列表转换为字符串和int数组来创建对象

Question

我试图从数据库中选择列，然后为每个列创建一个单独的数组属性，并创建一个单独的对象。

public class Activity
{
    public string[] Quiz { get; set; }
    public int[] CompletedCount { get; set; }
}

结果的数据库输出将返回为:

IQueryable<QuizCompletedCount> results = _logContext.QuizCompletedCounts;

我从数据库中得到了以下格式的值。

Week        | Completed
---------------------------
Week 1      |   107
Week 2      |   104
Week 3      |   87
Week 4      |   49
Week 5      |   6

我是这样尝试的:

List<int> activityCount = new List<int>();
List<string> activity = new List<string>();

foreach (var element in results)
{
    activity.Add(element.Week);
    activityCount.Add(element.Completed);
}

var obj = new QuizActivity();
obj.CompletedCount = activityCount.ToArray();
obj.Week = activity.ToArray();

所需输出如下所示:

string str = "{\"Week\":[\"Week 1\",\"Week 2\",\"Week 3\",\"Week 4\",\"Week 5\"],\"CompletedCount\":[107,104,87,49,6]}";

是否有LINQ方法可以在不使用foreach和从列表到数组的多次转换的情况下完成此任务？

Answer 1

你可以做这样的东西:

var result = new QuizActivity()
{
    Week = results.Select(x => x.Week).ToList(),
    CompletedCount = results.Select(x => x.Completed).ToList()
};