[英]ListBox, list of different objects implementing the same interface
I have two objects: User and Client, both implements interface IMember 我有两个对象:User和Client,都实现了接口IMember
interface IMember
{
int Id { get; set; }
string Name { get; set; }
}
In a form I set ListBox data source: 在表单中我设置了ListBox数据源:
myListBox.DisplayMember = "Name";
myListBox.ValueMember = "Id";
myListBox.DataSource = membersList; // List<IMember>
And wierd things happen ;) When I run program the first object, whichis type of User, displays correctly (Adrian Serafin) and other objects, wich are type of Contact are displayed like this: 并且发生了奇怪的事情;)当我运行程序时,第一个对象(正是这种类型的用户)正确显示(Adrian Serafin)和其他对象,其类型的联系人显示如下:
MyProject.Client#20
MyProject.Client#40
as for display was ToString() call on them. 至于显示是对它们的ToString()调用。
I can't using list of different objects implementing the same interface as datasource in ListBox or I made some mistake here? 我不能使用ListBox中实现相同接口的不同对象列表作为数据源,或者我在这里犯了一些错误?
Are you sure it is List<IMember>
, and not ArrayList
? 你确定它是List<IMember>
,而不是ArrayList
吗? This makes a big difference, as the existence of a non- object
public indexer ( public SomeType this[int] {get;set;}
) makes a big difference. 这有很大的不同,因为非object
公共索引器( public SomeType this[int] {get;set;}
)的存在会产生很大的不同。 The following works fine: 以下工作正常:
using System;
using System.Collections.Generic;
using System.Windows.Forms;
interface IMember
{
int Id { get; set; }
string Name { get; set; }
}
class Foo : IMember
{
public int Id { get; set; }
public string Name { get; set; }
}
class Bar : IMember
{ // explicit, why not...
int IMember.Id { get; set; }
string IMember.Name { get; set; }
}
static class Program
{
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
IMember bar = new Bar();
bar.Id = 2;
bar.Name = "def";
var list = new List<IMember> {
new Foo { Id = 1, Name = "abc"},
bar,
};
Application.Run(new Form
{
Controls = {
new ListBox {
Dock = DockStyle.Fill,
DisplayMember = "Name",
ValueMember = "Id",
DataSource = list
}
}
});
}
}
Members are property of class Event: 成员是班级活动的财产:
[ActiveRecord("cpa_events")]
public class Event : ARBase<Event>
{
private IList<Interfaces.IMember> _members = new List<Interfaces.IMember>();
[HasManyToAny(typeof(Interfaces.IMember),"event_id","cpa_events_members", typeof(int), "member_type", "member_id", MetaType=typeof(string))]
[Any.MetaValue("User", typeof(User))]
[Any.MetaValue("Client", typeof(Client))]
public IList<Interfaces.IMember> Members
{
get { return _members; }
set { _members = value; }
}
}
I'm using AR so members list has to be IList and underneath isn't List but NHibernate.Collection.Generic.PersistentGenericBag[Interfaces.IMember]. 我正在使用AR,所以成员列表必须是IList,而下面不是List而是NHibernate.Collection.Generic.PersistentGenericBag [Interfaces.IMember]。 Is this making a difference? 这有什么不同吗?
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