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从接口引发事件(win表单)

event-handling interface events winforms vb.net

1

Tanner · 技术社区 · 17 年前

我的设想:

Public Interface IDoSomething

Event AddFilter()

模式弹出窗口实现界面和贴花事件:

Public Class frmPopup Implements IDoSomething

Public Event AddFilter() Implements IDoSomething.AddFilter

RaiseEvent AddFilter()

基本主窗体包含发现和启动实现指定接口的弹出窗体的代码。

应用程序中的表单启动弹出窗口(实现接口)并处理它触发的任何事件。因此,我在表格中有以下代码:

Public Class frmMyForm

Public WithEvents m_Popup As IDoSomething

Public Sub m_Popup_AddFilter() Handles m_Popup.AddFilter

    MsgBox("I'm in")

End Sub

Public Function GetBusinessObjectUsingPopup(Of O, F As IBusinessObjectSelector)
               (ByRef dicPropertyValues As Dictionary(Of String, Object), 
                Optional ByVal titleText As String = "") 
                As O Implements IBaseMasterForm.GetBusinessObjectUsingPopup

Dim objBusinessObjectSelector As IBusinessObjectSelector = GetPopup(Of F)(False)       
    objBusinessObjectSelector.InitialiseForm()

    ' Activate and show the dialog
    If objBusinessObjectSelector.ShowPopup() <> Windows.Forms.DialogResult.OK Then
        ' The user cancelled the load, so just exit
        Return Nothing
    End If

    GetBusinessObjectUsingPopup = CType(objBusinessObjectSelector.SelectedBusinessObject, O)

End Function

和弹出代码:

Public Function GetPopup(Of F As IBasePopupChildForm)
            (Optional ByVal initialisePopupPriorToReturn As Boolean = True) As F 
             Implements IBaseMasterForm.GetPopup

    Dim lstIBasePopupChildForm As List(Of F) = GetInterfaces(Of F)()
            lstIBasePopupChildForm(0).MyIBaseMasterForm = Me
    If initialisePopupPriorToReturn Then
        lstIBasePopupChildForm(0).InitialiseForm()
    End If
    Return lstIBasePopupChildForm(0)
End Function

注意-GetInterfaces(Of F)()只是扫描程序集并返回实现所需接口的表单列表。一些验证已经被截断,如果找到实现该接口的多个表单,则返回消息。

1 回复 | 直到 12 年前

1

3

Hans Passant 17 年前

关键部分是正确初始化m_弹出窗口。你还没说过什么。一些示例代码:

表格2:

Public Class Form2
    Implements IDoSomething
    Public Event AddFilter() Implements IDoSomething.AddFilter

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        RaiseEvent AddFilter()
    End Sub
End Class

Public Interface IDoSomething
    Event AddFilter()
End Interface

表格1:

Public Class Form1
    Private WithEvents mPopup As IDoSomething

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim f2 As New Form2
        f2.Show(Me)
        mPopup = f2
    End Sub

    Private Sub mPopup_AddFilter() Handles mPopup.AddFilter
        MsgBox("yada")
    End Sub
End Class

此代码中的mPopup=f2语句是键。