使用.NET 2.0/VB.NET中的謂詞計算List（Of structure）中的項目

Question

我需要計算符合.NET 2.0中的List(Of Structure)中的條件的項目。例如：

Dim listcars as New List(Of car) 

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

現在我需要計算所有名稱豐田汽車等汽車。我該怎麼做？

Answer 1

你想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) 

Answer 2

的語法是公然錯的，但這樣的事情：

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

Answer 3

你在這裏。

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

Answer 4

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