.net – Catch块没有捕获异常

我有一个子窗体,它在Load事件处理程序中抛出ApplicationException(故意用于测试目的).父表单在Try … Catch ex As Exception块中包装ChildForm.Show()方法. catch块只显示一条消息并关闭子表单.在visual studio 2008(.net 3.5 sp1)中调试时,所有工作都按预期工作.但是,当我在visual studio之外运行它时,Catch块似乎错过了,并且发生了未处理的异常.知道为什么会这样吗？

谢谢.

示例代码：

Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles Button1.Click
        Dim f2 As Form2

        f2 = New Form2

        Try
            MessageBox.Show("Opening form 2")
            f2.ShowDialog()
        Catch ex As Exception
            f2.Close()
            MessageBox.Show("Form 2 closed.")
        End Try
    End Sub

End Class

Public Class Form2

    Private Sub Form2_Load(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles MyBase.Load
        Throw New ApplicationException("Test Form_Load")
    End Sub

    Public Sub New()

        ' This call is required by the Windows Form Designer.
        InitializeComponent()

        ' Add any initialization after the InitializeComponent() call.
    End Sub

End Class

堆栈跟踪：

 System.ApplicationException:
 Test Form_Load   at WindowsApplication1.Form2.Form2_Load(Object sender,EventArgs e)
 in UnhandledExceptionTest2WindowsApplication1Form2.vb
 System.Windows.Forms.Form.OnLoad(EventArgs e)
 System.Windows.Forms.Form.OnCreateControl()
 System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
 System.Windows.Forms.Control.CreateControl()
 System.Windows.Forms.Control.WmShowWindow(Message& m)    at
 System.Windows.Forms.Control.WndProc(Message&> m)    at
 System.Windows.Forms.ScrollableControl.WndProc(Message&> m)    at
 System.Windows.Forms.ContainerControl.WndProc(Message&> m)    at
 System.Windows.Forms.Form.WmShowWindow(Message&> m)    at
 System.Windows.Forms.Form.WndProc(Message&> m)    at
 System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message&> m)    at
 System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message&> m)    at
 System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd,Int32 msg,IntPtr wparam,IntPtr
 lparam)