我为我的自定义控件创建了一个自定义设计器 (PannelloSfondoDesigner
),即背景面板 (PannelloSfondo
)。
<Designer(GetType(PannelloSfondo.PannelloSfondoDesigner))>
Public Class PannelloSfondo
Inherits UserControl
Friend Class PannelloSfondoDesigner
Inherits ParentControlDesigner
Public Overrides Sub Initialize(ByVal component As IComponent)
MyBase.Initialize(component)
verbDock = New DesignerVerb("Dock to parent container", New EventHandler(AddressOf Me.OnDock))
verbUndock = New DesignerVerb("Undock from parent container", New EventHandler(AddressOf Me.OnUndock))
verbs = New DesignerVerbCollection()
If Me.Control.Dock = DockStyle.Fill Then
verbs.Add(verbUndock)
Else
verbs.Add(verbDock)
End If
End Sub
Public Overrides ReadOnly Property Verbs() As DesignerVerbCollection
Get
Return verbs
End Get
End Property
Private Sub OnDock(ByVal sender As Object, ByVal e As EventArgs)
'Dim verbo As DesignerVerb = DirectCast(sender, DesignerVerb)
verbs.Clear()
verbs.Add(verbDock)
Me.Control.Dock = DockStyle.Fill
End Sub
Private Sub OnUndock(ByVal sender As Object, ByVal e As EventArgs)
verbs.Clear()
verbs.Add(verbUndock)
Me.Control.Dock = DockStyle.None
End Sub
Public Overrides Function CanBeParentedTo(ByVal parentDesigner As IDesigner) As Boolean
Return True
End Function
Private verbs As DesignerVerbCollection = Nothing
Private verbDock As DesignerVerb
Private verbUndock As DesignerVerb
End Class
End Class
它有效,我单击小箭头,出现上下文菜单:
我单击菜单项,事件被触发,控件被停靠:
但菜单描述未更新或刷新(它应显示“从父容器取消停靠”)。然后,如果我单击控件外部以取消选择它,然后单击箭头以显示菜单,则会显示右侧菜单项:
如何刷新菜单项?! 谢谢。
最佳答案
你可能把动词搞混了吗?
在您的代码中,当您对其进行 Dock-Filling 时,您会清除动词,然后添加 verbDock,而不是 verbUndock。
Private Sub OnDock(ByVal sender As Object, ByVal e As EventArgs)
'Dim verbo As DesignerVerb = DirectCast(sender, DesignerVerb)
verbs.Clear()
'Switch verbs:
'verbs.Add(verbDock)
verbs.Add(verbUndock)
Me.Control.Dock = DockStyle.Fill
End Sub
Private Sub OnUndock(ByVal sender As Object, ByVal e As EventArgs)
verbs.Clear()
'Switch verbs:
'verbs.Add(verbUndock)
verbs.Add(verbDock)
Me.Control.Dock = DockStyle.None
End Sub
更新:
尝试更改设计器类以不清除集合,只需切换 Verb 集合的 Visible 属性即可:
Public Overrides Sub Initialize(ByVal component As IComponent)
MyBase.Initialize(component)
verbDock = New DesignerVerb("Dock to parent container", New EventHandler(AddressOf Me.OnDock))
verbUndock = New DesignerVerb("Undock from parent container", New EventHandler(AddressOf Me.OnUndock))
verbs = New DesignerVerbCollection()
verbs.Add(verbDock)
verbs.Add(verbUndock)
If Me.Control.Dock = DockStyle.Fill Then
verbDock.Visible = False
Else
verbUndock.Visible = False
End If
End Sub
Private Sub OnDock(ByVal sender As Object, ByVal e As EventArgs)
Me.Control.Dock = DockStyle.Fill
verbUndock.Visible = True
verbDock.Visible = False
End Sub
Private Sub OnUndock(ByVal sender As Object, ByVal e As EventArgs)
Me.Control.Dock = DockStyle.None
verbDock.Visible = True
verbUndock.Visible = False
End Sub
关于.NET Windows 窗体自定义设计器不刷新菜单,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/7905255/