处理事件

Question

处理事件通过COM在VB6暴露在.NET类

我的测试.NET（类libary在编译器设置注册的互操作）代码：

Imports System.Runtime.InteropServices 

<InterfaceType(ComInterfaceType.InterfaceIsIDispatch), ComVisible(True)> _ 
Public Interface MyEventInterface 
    <DispId(1)> Event Exploded(ByVal Text As String) 
    <DispId(2)> Sub PushRedButton() 
End Interface 


<ClassInterface(ClassInterfaceType.None)> _ 
Public Class EventTest 
    Implements MyEventInterface 

    Public Event Exploded(ByVal Text As String) Implements MyEventInterface.Exploded 

    Public Sub PushRedButton() Implements MyEventInterface.PushRedButton 

     RaiseEvent Exploded("Bang") 

    End Sub 

End Class 

我的测试VB6应用程序的WinForms代码（引用上面的类libary）：

Public ct As New ComTest1.EventTest 

Private Sub Command1_Click() 

    ct.add_Exploded (ExplodedHandler) 

    ct.PushRedButton 

    ct.remove_Exploded (ExplodedHandler) 

End Sub 

Private Sub ExplodedHandler(ByVal Text As String) 

    MsgBox Text 

End Sub 

Specifially我不知道如何设置处理程序在VB6编译错误我得到的是“参数不选择有理”在这条线在VB6：

ct.add_Exploded (ExplodedHandler) 

Answer 1

使用<ComSourceInterfaces(GetType(接口名))>在.NET中的事件和WithEvents在VB6

.NET类libary：

Imports System.Runtime.InteropServices 

' This interface is to expose the events 
<Guid("28C7DCE1-90EF-4a30-AF7F-4187F9FFFDEB")> _ 
<InterfaceType(ComInterfaceType.InterfaceIsIDispatch)> _ 
Public Interface MathsEvents 
    <DispId(1)> _ 
    Sub Calculated(ByVal Result As Double) 
End Interface 

' This interface is to expose the properties and methods 
<Guid("86CE5E8D-777D-4cd5-8A7D-7F58737F1DB4")> _ 
<InterfaceType(ComInterfaceType.InterfaceIsIDispatch)> _ 
Public Interface _Maths 
    <DispId(2)> _ 
    Property ValueA() As Double 
    <DispId(3)> _ 
    Property ValueB() As Double 
    <DispId(4)> _ 
    ReadOnly Property Result() As Double 
    <DispId(5)> _ 
    Sub Add() 
End Interface 

' This is the actual class 
' The events are exposed by using the ComSourceInterfaces attribute 
' The properties and methods are exposed using the Implements keyword 
<Guid("C58721B1-15B3-4eeb-9E1E-BCDA33D38EE6")> _ 
<ClassInterface(ClassInterfaceType.None)> _ 
<ComSourceInterfaces(GetType(MathsEvents))> _ 
Public Class Maths 
    Implements _Maths 
    Public Event Calculated(ByVal Result As Double) 
    Private mValueA As Double 
    Private mValueB As Double 
    Private mResult As Double 

    Public Property ValueA() As Double Implements _Maths.ValueA 
     Get 
      Return mValueA 
     End Get 
     Set(ByVal value As Double) 
      mValueA = value 
     End Set 
    End Property 

    Public Property ValueB() As Double Implements _Maths.ValueB 
     Get 
      Return mValueB 
     End Get 
     Set(ByVal value As Double) 
      mValueB = value 
     End Set 
    End Property 

    Public ReadOnly Property Result() As Double Implements _Maths.Result 
     Get 
      Return mResult 
     End Get 

    End Property 

    Public Sub New() 
     mValueA = 0 
     mValueB = 0 
     mResult = 0 
    End Sub 

    Public Sub Add() Implements _Maths.Add 
     mResult = mValueA + mValueB 
     RaiseEvent Calculated(mResult) 
    End Sub 

End Class 

VB6测试应用：

Private WithEvents calc As Maths 

Private Sub btnAdd_Click() 

    calc.ValueA = CDbl(txtValueA.Text) 
    calc.ValueB = CDbl(txtValueB.Text) 
    calc.Add 

End Sub 

Private Sub calc_Calculated(ByVal Result As Double) 
    txtResult.Text = CStr(Result) 
End Sub 

Private Sub Form_Load() 

    Set calc = New Maths 

End Sub 

Answer 2

C＃

[ComVisible(true)] //Exposed 
[InterfaceType(ComInterfaceType.InterfaceIsIDispatch)] //Our managed interface will be IDispatch 
public interface IMathEvents 
{ 

    void OnOperationCompleted(string message); 

} 
[ComVisible(true)] 
[ClassInterface(ClassInterfaceType.None)] 
[ComSourceInterfaces(typeof(IMathEvents))] //Our event source is IMathEvents interface 
[ComDefaultInterface(typeof(IMath))] 
public class Math:IMath /*IMath interface just declares a method named Add */ 
{ 
    public int Add(int x, int y) 
    { 
     if (null != this.OnOperationCompleted) 
      this.OnOperationCompleted("Operation completed, result: " + (x+y).ToString()); 
     return x + y; 
    } 

    [ComVisible(false)] 
    public delegate void OperationCompletedDel(string message); //No need to expose this delegate 
    public event OperationCompletedDel OnOperationCompleted; 

} 
[ComVisible(true)] 
public interface IMath 
{ 
    int Add(int x, int y); 
} 

VB

私人WITHEVENTS米作为数学

私人小组的Form_Load（）

Set m = New PayClient.Math 

结束子

私人小组m_OnOperationCompleted（BYVAL文本作为字符串）

MsgBox Text 

末次

私人小组Command2_Click（）
m.Add 1，2

末次