vb.net代码关闭另一个打开的窗体

这是相当基本的，但我搞不懂

如果form1仍然打开，我想在form2关闭时以编程方式关闭form1。Form2是由form1上的命令按钮打开的

打开Form2的Form1上的代码为：

Dim frm As New form2
frm.Show()

---

当Form2关闭时，关闭任何打开的Form1副本的最佳方法是什么？

如果您想独立处理两个表单，您需要从第三个表单或类中监视它们。所以我的建议是在第三个类中创建这两个表单，并将第二个表单的引用传递给第一个表单，这样它就可以打开它。这样：

Public Class MyHelper

    Public Sub CreateForms()
        Dim form2 as New Form2()
        AddHandler form2.Closed, AddressOf Form2_OnClosed

        ‘ Create as many copies as you need
        Dim form1 as New Form1(form2)
        form1.Show()
    End Sub

    Protected Sub Form2_OnClosed(sender as object, e as EventArgs) 
        ‘ Same code for each form1 that has been created and opened.
        If (form1.IsOpen) Then form1.Close()
    End Sub

End Class


Public Class Form1

    Private _form2 as Form2

    Public Property IsOpen as Boolean = false

    Public Sub New(form2 as Form2)
        _form2 = form2
    End Sub

    Protected Sub MyButton_Click(sender as object, e as EventArgs) handles MyButton.Click
        ‘ You open your form here or wherever you want (even on the constructor)
        _form2.Show()
    End Sub

    Protected Sub Me_OnClosed(sender as object, e as EventArgs) handles Me.Closed
        Me.IsOpen = false
    End Sub

    Protected Sub Me_OnShown(sender as object, e as EventArgs) handles Me.Shown
        Me.IsOpen = true
    End Sub

End Class

---

添加此引用以使其正常工作

Imports System.Linq

If Application.OpenForms().OfType(Of Form1).Any Then
   MsgBox("Form1 is open")
End If

---

假设您有3个表单，并希望在单击按钮时关闭另外两个表单

Private Sub EMPLEADOToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles EMPLEADOToolStripMenuItem.Click
    If Application.OpenForms().OfType(Of BUSCAR_INDEX).Any Then
        BUSCAR_INDEX.Close()
    ElseIf Application.OpenForms().OfType(Of MIEMBROS_INDEX).Any Then
        MIEMBROS_INDEX.Close()
    End If
    EMP_INDEX.Show()
    EMP_INDEX.EmpIDTextBox.Text = EmpIDTextBox.Text
End Sub

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只需为FormClosed事件添加一个事件处理程序并调用我。Close（）我正在尝试向form2添加一个事件处理程序，这样当它关闭时，它就会关闭form1（如果form1打开）。Me.Close（）将关闭form2，不是吗？如何关闭form1？不，代码属于form1类。很难理解为什么这是一个问题，也许您还不知道AddHandler语句。将AddHandler frm.FormClosed、AddressOf（yadayada）作为您发布的代码段中的第二条语句。添加yadayada方法，它所需要做的就是Me.Close（），那么我如何判断表单是否打开？如果用户可能在form2打开后关闭了它呢？