创建匿名类的集合

Question

I'm writing a bit of code, and I'd like to play with doing it using the anonymous features of C#.

I'm writing a summary based on a DataTable returned from the SQL Server.

There are many ways I could write it already knowing Classical C# (???), but I'm interested in having a little fun.

So, here are the type of anonymous classes I want to have:

// Employee
var emp = new {
  Badge = "000000",
  Name = "No Name",
  Parts = new List<Part>(),
  Days = new List<DateTime>(),
};

// Part
var part = new {
  SerialNumber = "N/A",
  Date = DateTime.MinValue,
  Badge = "000000",
};

Now, as I iterate over my DataTable entries, I want to sort my Parts by SerialNumber .

The first thing I have to do is break the data down into days.

private void TestMethod(DateTime minDate, DateTime maxDate, DataTable table) {
  int days = 1;
  var nextDay = minDate.AddHours(24);
  foreach (DataRow row in table.Rows) {
    var dateTime = (DateTime)row["Date_Time"];
    var emp = new {
      Badge = row["Badge"].ToString(),
      Parts = new List<Part>(),
      Days = new List<DateTime>(),
    };
    var part = new {
      SerialNumber = row["Serial_Number"].ToString(),
      Date = dateTime,
      Badge = row["Badge"].ToString(),
    };
    if (nextDay < dateTime) {
      days++;
      nextDay = nextDay.AddHours(24);
    }
  }

Now, it is getting a little interesting.

I need a way to store Part information for the different days and the different employees found for the period.

How would I create and use an anonymous collection of my anonymous class items?

var parts = new List<typeof(part)>();
var emps = new List<typeof(emp)>();

Using typeof (above) does not work!

What does?

Answer 1

You need to use type inference:

new[] { part }.ToList()

(you probably want to clear the list afterwards)

You can also make a helper method:

public static List<T> ListOf<T>(T sample) {
    return new List<T>();
}
var parts = ListOf(part);