窗体刚加载就发生Form.closing ?(VS2008)

[BeyondTimeSpace]

查了很久居然找不出原因，难道又是VS2008的Bug???

现象是：点击设置按钮
第一次点击：窗体显示后马上消失
第二次点击：窗体正常显



主窗体：

    Private Sub menuSetting_Setting_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles menuSetting_Setting.Click
        frmSetting.ShowDialog(Me)
        m_Tester.SetFactModel(m_FactModel)          '设置完后也要更新厂商型号
    End Sub

设置窗体：

Public Class frmSetting

    Private m_Form As Control

    Private Sub frmSetting_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        CType(m_Form, Form).Close()         '在关闭前先关闭当前设置窗体,触发当前窗体的Close事件
    End Sub

    Private Sub frmSetting_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Me.ShowInTaskbar = False
        Me.Show()
        Me.AutoScroll = True
        TableLayoutPanel1.Dock = DockStyle.Fill

        SetBtnColor(btnSetStep)
        My.Computer.FileSystem.CopyFile(fName1, fNameTmp1, True) '创建临时文件
        My.Computer.FileSystem.CopyFile(fName2, fNameTmp2, True)
        LoadForm(frmSettingStep)
    End Sub

    Private Sub btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSetStep.Click, btnTPLStep.Click, btnTPLCmp.Click, btnSystem.Click, btnExit.Click
        If sender.Equals(btnSetStep) Then       '步骤设置
            SetBtnColor(btnSetStep)
            LoadForm(frmSettingStep)
        ElseIf sender.Equals(btnTPLStep) Then   '步骤模板设置
            SetBtnColor(btnTPLStep)
            LoadForm(frmSettingTPLStep)
        ElseIf sender.Equals(btnTPLCmp) Then    '对比模板设置
            SetBtnColor(btnTPLCmp)
            LoadForm(frmSettingTPLCmp)
        ElseIf sender.Equals(btnSystem) Then    '系统变量设置
            SetBtnColor(btnSystem)
            LoadForm(frmSettingSystem)
        ElseIf sender.Equals(btnExit) Then      '退出
            Me.Close()
        End If

    End Sub


    Private Sub SetBtnColor(ByVal currentButton As Button)
        Dim btn As Button
        For Each btn In GBoxButton.Controls
            btn.BackColor = Color.Empty
        Next
        currentButton.BackColor = Color.GreenYellow
    End Sub

    Private Sub LoadForm(ByVal ctlForm As Control)
        If Not ctlForm.Equals(m_Form) Then
            UnloadCurrentForm()
            m_Form = ctlForm
            LoadSubForm(m_Form, Me.GroupBox1)
        End If
    End Sub
    Private Sub UnloadCurrentForm()
        If Not m_Form Is Nothing Then
            CType(m_Form, Form).Close() '用Form.close才能引发Form.closing事件
        End If
    End Sub

End Class

[llsus]

程序写的太深奥了，看不懂。

[只在此山中]

问题可能出在LoadForm
这1次执行时 If Not ctlForm.Equals(m_Form) Then 不是同一对象,执行了UnloadCurrentForm()

[yanlongwuhui]

设置断点，单步跟踪，主要是LoadForm

[pxb0420]

太乱了！！
问题比较多。
m_Form上来定义类型就不对呀

[BeyondTimeSpace]

自己单独做了个测试工程，问题解决了，但还是没搞懂：

如果：
■将设置窗体显示为非模式窗体
■设置窗体中Me.ShowInTaskbar = False这句删除也OK

估计还有更多的途径解决这个问题，但却搞不懂为什么？希望有高手解释下，如果能找到根本原因，将赠送300积分。