vb.net 对象初始值设定项列表(Of T)

vb.net Object Initialiser List(Of T)

提问by Tim B James

I have been looking at some C# code:

我一直在看一些 C# 代码：

List<Employee> Employees = new List<Employee>{
    new Employee{firstname="Aamir",lastname="Hasan",age=20},
    new Employee{firstname="awais",lastname="Hasan",age=50},
    new Employee{firstname="Bill",lastname="Hasan",age=70},
    new Employee{firstname="sobia",lastname="khan",age=80},  
    };

Now when I convert this to vb.net

现在当我将其转换为 vb.net

Dim Employees as List(Of Employee) = New List(Of Employee)() With { New Employee() With { _  
.firstname = "Aamir", _  
.lastname = "Hasan", _   
.age = 20 _  
}, _  
New Employee() With { _  
.firstname = "awais", _  
.lastname = "Hasan", _  
.age = 50 _  
}, _  
New Employee() With { _  
.firstname = "Bill", _  
.lastname = "Hasan", _  
.age = 70 _  
}, _  
New Employee() With { _  
.firstname = "sobia", _  
.lastname = "khan", _  
.age = 80 _  
} _  
}  

I get the error "Name of field or property being initialized in an object initializer must start with'.'."

我收到错误“在对象初始值设定项中初始化的字段或属性的名称必须以'.'开头。”

Now I can get an array of employee using the code:

现在我可以使用代码获取一组员工：

Dim Employees = { New Employee() With { _  
.FirstName = "Aamir", _  
.LastName = "Hasan", _   
.Age = 20}, _  
New Employee() With { _    
.FirstName = "Awais", _   
.LastName = "Hasan", _  
.Age = 50}, _
New Employee() With { _
.FirstName = "Bill", _ 
.LastName = "Hasan", _  
.Age = 70 _
} _  
}    

But I would like a List(Of Employee)as it is bugging me as to why this doesnt work in vb.net?

但我想要一个，List(Of Employee)因为它在困扰我为什么这在 vb.net 中不起作用？

回答by MarkJ

Collection initialisers were added in VB.NET 2010. This is air code, but here goes:

在 VB.NET 2010中添加了集合初始值设定项。这是航空代码，但这里是：

Dim Employees as List(Of Employee) = New List(Of Employee)() From
{ 
    New Employee() With { _   
       .firstname = "Aamir", _
       .lastname = "Hasan", _ 
       .age = 20 _   
    }, _
   New Employee() With { _  
       .firstname = "awais", _  
       .lastname = "Hasan", _ 
       .age = 50 _ 
    }, _ 
   New Employee() With { _ 
       .firstname = "Bill", _ 
       .lastname = "Hasan", _ 
       .age = 70 _ 
    }, _  
   New Employee() With { _ 
       .firstname = "sobia", _ 
       .lastname = "khan", _ 
       .age = 80 _ 
    } _ 
}   

回答by dxh

EDIT(2)
As pointed out in comments, VB.NET collection initializershave now been introduced, and a lot of the following post should be considered obsolete.

编辑(2)
正如评论中所指出的，现在已经引入了VB.NET 集合初始值设定项，下面的很多帖子都应该被认为是过时的。

EDIT
Don't always blindly trust the C# to VB.NET converter
Here's a handy tool for online conversion

编辑
不要总是盲目地相信 C# 到 VB.NET 转换器
这里有一个方便的在线转换工具

Turns out VB.NET doesn't have collection initializers. Which means there is no equivalence of

原来VB.NET 没有集合初始值设定项。这意味着没有等价的

var myList = new List<string>()
{
   "abc",
   "def"
};

... but it doeshave object initializers. So you can create an instance of a class and assign values to its properties all in one go, but you cannot create an instance of a list and add items to it all in one go.

...但它确实有对象初始值设定项。因此，您可以一次性创建一个类的实例并为其属性赋值，但是您不能一次性创建一个列表的实例并向其中添加项目。

There closest you can get is in the link above. You can create an Arrayand add items to it in a single operation, and then you have to ToListthat array.

您可以在上面的链接中找到最接近的位置。您可以在单个操作中创建一个数组并向其中添加项目，然后您必须添加到ToList该数组。

So this time I've actually compiled the code myself, and it works. Sorry for the hassle

所以这次我实际上是自己编译了代码，并且它有效。抱歉给您带来麻烦

    Dim EmployeesTemp As Employee() = { _
        New Employee() With { _
            .firstname = "Aamir", _
            .lastname = "Hasan", _
            .age = 20 _
        }, _
        New Employee() With { _
            .firstname = "awais", _
            .lastname = "Hasan", _
            .age = 50 _
        }, _
        New Employee() With { _
            .firstname = "Bill", _
            .lastname = "Hasan", _
            .age = 70 _
        }, _
        New Employee() With { _
            .firstname = "sobia", _
            .lastname = "khan", _
            .age = 80 _
        } _
    }

    Dim Employees as List(Of Employee) = EmployeesTemp.ToList()

回答by Eric

How about this?

这个怎么样？

Dim Employees As List(Of Employee) = { _
  New Employee() With { .firstname = "Aamir", .lastname = "Hasan", .age = 20 }, _
  New Employee() With { .firstname = "awais", .lastname = "Hasan", .age = 50 }, _
  New Employee() With { .firstname = "Bill",  .lastname = "Hasan", .age = 70 }, _
  New Employee() With { .firstname = "sobia", .lastname = "khan",  .age = 80 } _
}.ToList()