Remove/Unsubscribe 从基础 Class 派生 Class 加载事件

Question

我有一个基础 class 检查用户是否有权访问派生表单。如果用户无权访问表单，我需要 block/remove invoke/unsubscribe 派生 class 中的所有 methods/events 来自基础 class。

我尝试了很多方法，但找不到解决这个问题的方法。

我的方法是在基本表单加载事件中关闭表单，但是如果在派生表单加载事件中加载数据，它也会在数据加载后引发和关闭。这可能是一些安全问题的泄漏。

我可以通过向派生形式添加一些代码来轻松解决这个问题，但我有大约 450~500 个关于派生形式的代码。

或者我可以定义一个函数来显示表单，在显示之前检查表单中的用户角色，但由于有许多派生表单，我无法更改。

Public Class AuthBaseForm
    Inherits DevExpress.XtraEditors.XtraForm

    Property IsAuthorized As Boolean = False

    Private Sub InitializeComponent()

        Me.SuspendLayout()
        '
        'StartUpForm
        '
        Me.ClientSize = New System.Drawing.Size(825, 432)
        Me.Name = "AuthBaseForm"
        Me.AutoScaleMode = Windows.Forms.AutoScaleMode.Dpi
        Me.ResumeLayout(False)

    End Sub

    Public Sub New()
        MyBase.New()

        ' Here checks if user can access and visible this form
        ' function return true/false
        IsAuthorized = GetUserRoleInForm(Me)
    End Sub

    Private Sub Form_Load(sender As Object, e As EventArgs) Handles Me.Load
        If Not IsAuthorized Then
            'Remove Here Derived Class Load Event
            'Here, i need to find Derived class load event, and disable to invoke that method


            MsgBox("You do not have permissions to show this form!", vbExclamation + vbOKOnly)
            Me.Close()
            Return
        End If
    End Sub
End Class

Public Class DetailForm
    Inherits AuthBaseForm

    Public Sub New()

        ' This call is required by the designer.
        InitializeComponent()

    End Sub

    Private Sub DetailForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' this generated to test form role auth
        MsgBox("If also my base class not authorized, this event is raising :(", vbInformation)

        Me.KeyPreview = True

        ' Fetch data to show
        Me.WaitHelper1.SetListingFunction(Sub() Me.GetData())

        ' Set auto filter rows
        rh.devexFunc.SetGridViewFilterTypes(Me.viewSiparisler)

        ' Set column bolds
        rh.devexFunc.SetGridViewFontBold(Me.viewSiparisler, "UNVAN")
    End Sub
End Class

我尝试了一些作品，但仍然没有成功。

Answer 1

根据 Hans Passants 的解决方案，我修改了如下的基本 onLoad 方法并完美运行。

  Protected Overrides Sub OnLoad(e As EventArgs)
        If Me.IsAuthorized Then
            MyBase.OnLoad(e)
        Else
            Me.Close()
            rh.ExclamationMsgBox("You are not allowed to show this form!")
        End If
    End Sub

Remove/Unsubscribe 从基础 Class 派生 Class 加载事件

Remove/Unsubscribe Derived Class Load event from Base Class

vb.net

winforms