The wrong application may come to the foreground when you close a modal dialog box in a Windows Forms-based application on the .NET Framework 2.0 or on the .NET Framework 1.1

• Set the top-level form as the owner of the modal dialog box. To do this, you can use code that is similar to the following.

  MessageBox.Show(Me.Owner, "ok")

• Set the Owner property of the pop-up window to Nothing before you display the modal dialog box. To do this, you can use code that is similar to the following.

  Private Sub Button1_Click(...)
          Dim f As Form
          f = Me.Owner
          Me.Owner = Nothing
          MessageBox.Show("ok")
          Me.Owner = f
          Me.Close()
      End Sub

  Note When you set the Owner property of the pop-up window to Nothing, the focus is correctly reset to the active window or to the pop-up window.

Back to the top

Steps to reproduce the problem

1. On a computer that has the .NET Framework 2.0 or the .NET Framework 1.1 installed, start two or more applications.
2. Use Microsoft Visual Basic .NET to create a Windows Forms-based application.
3. Paste the following code sample in the Form1 form.

   Public Class Form1
       Inherits System.Windows.Forms.Form
   
   #Region " Windows Form Designer generated code "
   
       Public Sub New()
           MyBase.New()
   
           'This call is required by the Windows Form Designer.
           InitializeComponent()
   
           'Add any initialization after the InitializeComponent() call
   
       End Sub
   
       'Form overrides dispose to clean up the component list.
       Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
           If disposing Then
               If Not (components Is Nothing) Then
                   components.Dispose()
               End If
           End If
           MyBase.Dispose(disposing)
       End Sub
   
       'Required by the Windows Form Designer
       Private components As System.ComponentModel.IContainer
   
       'NOTE: The following procedure is required by the Windows Form Designer
       'It can be modified using the Windows Form Designer.  
       'Do not modify it using the code editor.
       Friend WithEvents Button1 As System.Windows.Forms.Button
       <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
           Me.Button1 = New System.Windows.Forms.Button
           Me.SuspendLayout()
           '
           'Button1
           '
           Me.Button1.Location = New System.Drawing.Point(80, 88)
           Me.Button1.Name = "Button1"
           Me.Button1.Size = New System.Drawing.Size(128, 23)
           Me.Button1.TabIndex = 0
           Me.Button1.Text = "Show ChildForm"
           '
           'Form1
           '
           Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
           Me.ClientSize = New System.Drawing.Size(292, 266)
           Me.Controls.Add(Me.Button1)
           Me.IsMdiContainer = True
           Me.Name = "Form1"
           Me.Text = "ParentForm"
           Me.ResumeLayout(False)
   
       End Sub
   
   #End Region
   
       Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
           Dim f As New Form2
           f.Owner = Me
           f.Show()
       End Sub
   
   End Class
   

4. Add a form that is named Form2 to the project.
5. Paste the following code sample in the Form2 form.

   Public Class Form2
       Inherits System.Windows.Forms.Form
   
   #Region " Windows Form Designer generated code "
   
       Public Sub New()
           MyBase.New()
   
           'This call is required by the Windows Form Designer.
           InitializeComponent()
   
           'Add any initialization after the InitializeComponent() call
   
       End Sub
   
       'Form overrides dispose to clean up the component list.
       Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
           If disposing Then
               If Not (components Is Nothing) Then
                   components.Dispose()
               End If
           End If
           MyBase.Dispose(disposing)
       End Sub
   
       'Required by the Windows Form Designer
       Private components As System.ComponentModel.IContainer
   
       'NOTE: The following procedure is required by the Windows Form Designer
       'It can be modified using the Windows Form Designer.  
       'Do not modify it using the code editor.
       Friend WithEvents Button1 As System.Windows.Forms.Button
       <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
           Me.Button1 = New System.Windows.Forms.Button
           Me.SuspendLayout()
           '
           'Button1
           '
           Me.Button1.Location = New System.Drawing.Point(96, 104)
           Me.Button1.Name = "Button1"
           Me.Button1.Size = New System.Drawing.Size(96, 23)
           Me.Button1.TabIndex = 0
           Me.Button1.Text = "Show MsgBox"
           '
           'Form2
           '
           Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
           Me.ClientSize = New System.Drawing.Size(292, 266)
           Me.Controls.Add(Me.Button1)
           Me.Name = "Form2"
           Me.ShowInTaskbar = False
           Me.Text = "ChildForm"
           Me.ResumeLayout(False)
   
       End Sub
   
   #End Region
   
       Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
           MessageBox.Show("ok")
           Me.Close()
       End Sub
   
       Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
   
       End Sub
   End Class
   
   

6. Press F5 to run the project.
7. Click Show ChildForm, click Show MsgBox, and then click OK.
8. Repeat step 7.

Back to the top