Question

以下是我的情景。我需要使用List.Foreach(addressof fn)调用。但似乎我们需要将对象作为列表类型和函数fn(Type of List as Arg)传递。我们可以有另一个参数吗？。

员工类

Class Employee
public  string Name
public  String DisplayName
End Class

-

Dim lstEmployee As New List(Of Employee)
Sub Main()
LoadEmployee()
PrintNames()
Update(5)
End Sub

Shared Sub PrintNames()
names.ForEach(AddressOf Print)     ' This will be working fine. 
End Sub

Shared Sub Update(Byval int as integer)
names.ForEach(AddressOf UpdateEmpName) ' Not possible
End Sub

Shared Sub LoadNames()
lstEmployee.Add(new Employee with{.Name="Bruce"})
lstEmployee.Add(new Employee with{.Name="Alfred"})
lstEmployee.Add(new Employee with{.Name="Tim"})
lstEmployee.Add(new Employee with{.Name="Richard"})
End Sub 

Shared Sub Print(ByVal s As Employee)
Console.WriteLine(s.Name)
End Sub 

Shared Sub UpdateEmpName(ByVal s As Employee. ByVal i as integer)
s.DisplayName= "EIN" +i+"-"+s.Name
End Sub

这可能吗？。我正在使用.net 3.5

Answer 1

我认为这是可能的，但是因为这是未经测试的代码，请尝试一下：

Shared Sub Update(Byval int as integer)
    names.ForEach(Sub(emp)
        UpdateEmpName(emp, int) 'param int from method update
    End Sub)
End Sub

我无法看到names被宣布在哪里，所以假设你已经把它放在哪里呢？

使用Linq foreach如何使用两个参数调用函数

1 个答案: