LINQ過濾對象列表

Question

我有列表對象，我需要在VB.NET使用LINQ逗號分隔字符串來查身份證，這樣的事情：

dim strId as String = "1,2,3,5," 
dim myList = from objmylist where objmylist.id in (strId) 

Answer 1

dim strId as String = "1,2,3,5," 
dim IDs as String() = strId.Split(",") 
dim myList = from objmylist where IDs.Contains(objmylist.id) 
      select objmylist 

Answer 2

dim strId as String = "1,2,3,5," 
dim myList = from objmylist where strId.split(",").Contains(objmylist.id) 

未經測試，但應該做的伎倆我猜。

Answer 3

你的代碼是完全正常的，如果你在LINQ 使用它在C＃中，你會做到這一點之前分割字符串：

string strIDs = "1,2,3,5,"; 
string[] arrIDs = strIDs.Split(","); 
var myList = objmylist.Where(o => arrIDs.Contains(o.id)); 

也許你能理解這一點足以把它翻譯成VB

Answer 4

使用C＃，

int[] productList = new int[] { 1, 2, 3, 4 }; 

var myProducts = from p in db.Products 
       where productList.Contains(p.ProductID) 
       select p; 

使用VB.NET，

Dim productList As Integer() = New Integer() {1, 2, 3, 4} 

Dim myProducts = From p In db.Products Where productList.Contains(p.ProductID) 

在從Creating SQL IN Queries using LINQ