vb.net：区分me.close()和x-button

Question

如何区分用户明确按下 x 按钮（或按下 ALT F4）以关闭表单的事件和所有其他以编程方式关闭表单的方法 (me.close( ）， ETC）。我已经想通了，这可以使用发件人对象来完成，但我真的不明白。有人可以举个例子给我解释一下吗？非常感谢大家。

Answer 1

就这么简单。 :)

Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As FormClosingEventArgs)
e.Cancel = True
End Sub

这将阻止 X 按钮关闭表单以及 :)。问题是，如果您这样做，您也无法使用 Me.Close 关闭表单，要解决此问题，只需删除 EventHandler :)

  RemoveHandler Me.Closing, AddressOf Form1_FormClosing
  'Now close the form
  Me.Close()

Answer 2

class FormClosingEventArgs 事件参数有一个枚举来说明表单关闭的原因。

https://msdn.microsoft.com/en-us/library/system.windows.forms.closereason(v=vs.110).aspx

Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As FormClosingEventArgs) Handles Me.Closing

    If Not appClosing AndAlso e.CloseReason = System.Windows.Forms.CloseReason.UserClosing Then

    ' DO WHATEVER CODE YOU WANT IN HERE
    ' LIKE SETTING E.CANCEL TO TRUE

    End If

End Sub

' You can also set a close appClosing local variable at the class level as a boolean, whenever you call closing in code, assign the variable.
appClosing = True
Me.Close();

vb.net：区分me.close()和x-button

vb.net: Distinguish between me.close() and x-button

vb.net

forms

events

sender

formclosing