Linq:How to make this easy with one line code?

Forget most learnt about linq,now need to review what is it. And how it works.now I need help for this. Please help me .Thank you so much. 

var everyMonthMoneySum = new EveryMonthMoneySum()
{
    M_01 = (from o in temp.Where(o => o.IsSign == (short) OrderStateEnum.Success && o.SignMonth == 1)
            select o.Signmoney).Sum(),
    M_02 = (from o in temp.Where(o => o.IsSign == (short) OrderStateEnum.Success && o.SignMonth == 2)
            select o.Signmoney).Sum(),
    M_03 = (from o in temp.Where(o => o.IsSign == (short) OrderStateEnum.Success && o.SignMonth == 3)
            select o.Signmoney).Sum(),
    M_04 = (from o in temp.Where(o => o.IsSign == (short) OrderStateEnum.Success && o.SignMonth == 4)
            select o.Signmoney).Sum(),
    M_05 = (from o in temp.Where(o => o.IsSign == (short) OrderStateEnum.Success && o.SignMonth == 5)
            select o.Signmoney).Sum()+5,
    ...........................
    M_11 = (from o in temp.Where(o => o.IsSign == (short) OrderStateEnum.Success && o.SignMonth == 11)
            select o.Signmoney).Sum(),
    M_12 = (from o in temp.Where(o => o.IsSign == (short) OrderStateEnum.Success && o.SignMonth == 12)
            select o.Signmoney).Sum()

};
Jon Skeet
people
quotationmark

It sounds to me like you could do with a dictionary:

var results = temp.Where(o => o.IsSign == (short) OrderStateEnum.Success)
                  .GroupBy(o => o.SignMonth)
                  .ToDictionary(g => g.Key, g => g.Sum(o => o.SignMoney));

Note that that won't populate the dictionary with entries for "missing" months.

That will give you a single collection, instead of 12 different variables. Personally I find that's usually a better approach, but we don't really know what you're trying to do with those 12 values...

If you want to make sure the dictionary is populated, I would personally do that with an extra loop afterwards:

for (int i = 1; i <= 12; i++)
{
    if (!results.ContainsKey(i))
    {
        results[i] = 0m;
    }
}

It's not "clever", but it works. Alternatively, you could populate an array from the dictionary:

var array = new decimal[13]; // 0 to 12 *inclusive*
foreach (var entry in array)
{
    array[entry.Key] = entry.Value;
}

There are other ways of doing it all in the LINQ statement, but I don't know how they'd play with whatever LINQ provider you're using (we don't know) and they're more complex.

people

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