实体的问题作为参数传递

Question

我有这段代码：

Public Class myclass
....
Private cont As MyentEntities
.....
.....

Public Sub New( ByRef cnx As MyentEntities)
   .....
    cont = cnx
    .....
End Sub

Public Sub test
.....

If cont.mytable1.Count=1 then

.....
end if 

End Sub
End class

'在我的主要表格上：

.......
Dim E1 as MyEntEntities
Dim m1 as myclass
Private Sub MainForm_Load(sender As System.Object, e As System.EventArgs)    
Handles Me.Load 

E1=New MyentEntities
m1=new MyClass(E1)
Fill_entity()
........

End Sub

Private sub fill_entity

E1.MyTable1.Tolist
....
End sub

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs)    
Handles Button1.Click

m1.test

End Sub

当我点击按钮时，出现错误：

....“MyTable1”类型的实体在上下文中不存在。

但是我用ByRef通过了E1？

怎么了？

谢谢！