var d = from d1 in pDT1.AsEnumerable()
from d2 in pDT2.AsEnumerable()
where d1.Field<string>("ID") == d2.Field<string>("ID")
select new { a = d1.Field<string>("ID"), v = d1.Field<double>("VALUE") * d2.Field<double>("VALUE") };
var d = pDT1.AsEnumerable().Join(pDT2.AsEnumerable(), s => s.Field<string>("ID"), sc => sc.Field<string>("ID"), (s, sc) => new
{
a = s.Field<string>("ID"),
v = s.Field<double>("VALUE") * sc.Field<double>("VALUE")
});
例子，三个DataTable之间的运算
var d = pDT1.AsEnumerable().Join(pDT2.AsEnumerable(), s => s.Field<string>("ID"), sc => sc.Field<string>("ID"), (s, sc) => new
{
a = s.Field<string>("ID"),
v = s.Field<double>("VALUE") * sc.Field<double>("VALUE")
});
DataTable pDT3 = pGetDT();
foreach (var l in d)
{
DataRow pDR = pDT3.NewRow();
pDR[] = l.a;
pDR[] = l.v;
pDT3.Rows.Add(pDR);
Console.WriteLine("{0} {1}", l.a, l.v);
}
var E = from d1 in d
from d2 in pDT1.AsEnumerable()
where d1.a == d2.Field<string>("ID")
select new { a = d1.a, v = Convert.ToDouble( d1.v) - d2.Field<double>("VALUE") };
foreach (var l in E)
{
Console.WriteLine("{0} {1}", l.a, l.v);
}
Console.ReadLine();