使用Linq合并数据

Question

我有一些代码将两个数组与一个名为seqNum2的标识符数组结合在一起。 我不太明白使用Linq合并第三个数组。 我的代码中的第三个数组是grossNGL2 。 当我从grossNGL2剔除grossNGL2时，它确实起作用，但我需要在其中。 这是代码：

private void grossOilMboeRadBtn_CheckedChanged(object sender, EventArgs e)
{
    using (var sw = new StreamWriter("testUltOilMBOE.txt"))
    {
        var items = grossOil2.Zip(seqNum2, (goil, seq) => new { GOIL = goil, Seq = seq }); //goil STANDS FOR GROSS OIL
        var items2 = grossGas2.Zip(seqNum2, (ggas, seq) => new { GGAS = ggas, Seq = seq }); //ggas STANDS FOR GROSS GAS
        var items3 = grossNGL2.Zip(seqNum2, (gngl, seq) => new { GNGL = gngl, Seq = seq }); //gngl STANDS FOR GROSS NGL

        //var olditems = ultOil.Zip(seqNum, (uoil, seq) => new { UOIL = uoil, Seq = seq });
        //var olditems2 = ultGas.Zip(seqNum, (ugas, seq) => new { UGAS = ugas, Seq = seq });

        foreach (var item in items.Join(items2, i => i.Seq, i => i.Seq, (a, b) =>
        {
            double first = Convert.ToDouble(a.GOIL);
            double second = Convert.ToDouble(b.GGAS);
            double third = Convert.ToDouble(c.GNGL);
            double answer = first + third + (second / 6);
            return string.Format("{0}, {1}", a.Seq, answer);
        }))
        {
            sw.WriteLine(item);
        }

如果有人可以告诉我如何将第三个数组添加到foreach循环中，将不胜感激。

Answer 1

对于联接，通常，综合（或查询）语法更容易：

var query = from i1 in items
            join i2 in items2 on i1.seq equals i2.seq
            join i3 in items3 on i1.seq equals i3.seq
            select new { i1, i2, i3 };

foreach(var x in query)
{
    double first = Convert.ToDouble(x.i1.GOIL);
    ....