Question

我再次完全陷入了我正在开发的用于提高我的C＃技能的Windows表单项目。

我需要获得每年薪水最高的职业（返回单个字符串，SalaryInformation对象的职业属性）。

让我向您展示SalaryInformation类的外观：

public sealed class SalaryInformation
{
    private string profession;
    private int yearOfEmployment;
    private decimal startSalary;
    private decimal currentSalary;

    public string Profession
    {
        get { return profession; }
        set { profession = value; }
    }

    public int YearOfEmployment
    {
        get { return yearOfEmployment; }
        set { yearOfEmployment = value; }
    }

    public decimal StartSalary
    {
        get { return startSalary; }
        set { startSalary = value; }
    }


    public decimal CurrentSalary
    {
        get { return currentSalary; }
        set { currentSalary = value; }
    }

    public SalaryInformation()
    { }

    public SalaryInformation(string p, int yoe, decimal startS, decimal currentS)
    {
        profession = p;
        yearOfEmployment = yoe;
        startSalary = startS;
        currentSalary = currentS;
    }

我已经知道如何计算一个职业每年的平均工资增长：

每年工资增加=（totalCurrentSalaries - totalStartingSalaries）/ totalYears;

现在我的方法代码如下：

 private string GetProfessionWithHighestSalaryIncrease()
    {
        List<SalaryInformation> allSalaries = new List<SalaryInformation>();
        allSalaries = data.GetSalaryInformation();

        //Here I got stuck. I think that this could be solved in a single linq query.
        //But since I have to make a calculation of EVERY salaryincrease of EVERY
        //profession, I keep getting stuck on how I should solve this.

        //After all, I need the sum of every professions CurrentSalaries, the sum
        //of every professions StartingSalaries and the sum of every professions
        //yearOfEmployment to be able to calculate that professions salaryincrease
        //per year.

        //The profession(string) with the highest salary increase per year, has to  be returned.


    }

我很确定这可以在一个组合的Linq / lambda表达式查询中解决。但我不习惯编写linq和lamdba表达式，所以我在语法上苦苦挣扎。

Answer 1

您可以使用group by对该集进行分区，然后按平均加薪顺序排序并取第一个：

string maxSalaryProfession = allSalaries

    // group by profession
    .GroupBy(info => info.Profession)

    // order rows by the average salary increase per profession
    .OrderByDescending(prof => 
        (prof.Sum(info => info.CurrentSalary) - prof.Sum(info => info.StartSalary))
            / prof.Sum(info => info.YearOfEmployment)
     )
     .First().Key;

Answer 2

一行：

allSalaries.OrderByDescending(s=>(s.CurrentSalary - 
 s.StartSalary)/s.YearOfEmployment).First().Profession

获取与每年最高增值相关的字符串？

2 个答案: