Count items in List(Of structure) using predicate in .NET 2.0/VB.NET

问题

I need to count the items that meet a criteria in a List(Of Structure) in .NET 2.0. For example:

Dim listcars as New List(Of car)

Structure car
   Dim Name as String
   Dim year as Integer
End structure

Now I need to count all cars with name Toyota, etc.. How do I do it?

回答1:

You want List.LongCount.

Dim CarList As New List(Of Car)
Dim Model As String = "Toyota"
Dim ToyotaCount As Long = CarList.LongCount(Function(car) car.Name = Model)

回答2:

Dim toyotas As Integer = carList.Count(Function(c) c.Name = "Toyota")

回答3:

Here you go.

 var count = carList.Count(x => x.Name == "Toyota");

回答4:

The syntax is blatantly wrong, but something like this:

Dim toyotas as Integer;
toyotas = 0;
foreach(car c in listcars){
    if(c.Name == "toyota")//make sure to do string comparison here.
        toyotas++;
}

来源：https://stackoverflow.com/questions/6823139/count-items-in-listof-structure-using-predicate-in-net-2-0-vb-net