Question

我正在开发一个Windows窗体应用程序。当用户点击主窗口中的“X”按钮时，我想向用户显示一条消息，说明接近原因。“X”按钮表示窗口中“最小化”，“最大化”和“关闭”托盘中的“关闭”按钮。 / p>

我已经写了这段代码。

 private void frmIMS_FormClosing(object sender, FormClosingEventArgs e)
    {
        if (MessageBox.Show("This application is closing down because of " + e.CloseReason.ToString() + ". Do you really want to close it ?", "", MessageBoxButtons.YesNo) == DialogResult.No)
        {                
            e.Cancel = true;
        }
        else
        {
            Application.Exit();
        }
    }

现在发生的情况是，如果用户单击no消息框，则事件被丢弃，当用户单击yes时，form_closing（）再次触发并显示其他messagebox.So messagebox显示两次。我想显示一次。请帮助并告诉它为什么要两次射击。

Answer 1

您可以跳过应用程序的其他部分。如果您的表单是主要的申请形式，它仍然会退出。 Application.Exit（）会导致所有窗口关闭。您的“第一次”关闭仍处于暂挂状态，因此表单尚未关闭，Application.Exit（）会尝试第二次关闭您的表单。

你可以试试这个：

bool closingPending = false;
private void frmIMS_FormClosing(object sender, FormClosingEventArgs e)
{
    if (closingPending) return;
    if (MessageBox.Show("This application is closing down because of " + e.CloseReason.ToString() + ". Do you really want to close it ?", "", MessageBoxButtons.YesNo) == DialogResult.No)
    {                
        e.Cancel = true;
    }
    else
    {
        closingPending = true;
        Application.Exit();
    }
}

Answer 2

我知道这个帖子有点旧，但为什么不呢：

    $Application.OpenForms["NameOfMainForm"].Close;

Answer 3

我知道这是旧的，我偶然发现了这个问题，因为我遇到了同样的行为。我正在使用.Net 4.5，以下是我如何解决这个问题：

private void frmIMS_FormClosing(object sender, FormClosingEventArgs e)
{
    if (e.CloseReason == CloseReason.UserClosing)
    {
        if (MessageBox.Show("This application is closing down because of " + e.CloseReason.ToString() + ". Do you really want to close it ?", "", MessageBoxButtons.YesNo) == DialogResult.No)
        {                
            e.Cancel = true;
        }
        else
        {
            Application.Exit();
        }
    }   
}

您可以在此处找到有关CloseReason枚举的更多信息：http://msdn.microsoft.com/en-us/library/system.windows.forms.closereason.aspx

Answer 4

为什么Application.Exit在else分支中？这是自动完成的，可以解决您的问题。

Answer 5

Private Sub ClaimEditor_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
    If MsgBox("Edit mode active. Exit without saving?", MsgBoxStyle.YesNo Or MsgBoxStyle.Question, "Edit mode") <> MsgBoxResult.Yes Then
        e.Cancel = True
        Exit Sub
        'Else
        '    e.Cancel = False
    End If
    WriteIntoRregistry()
    RemoveHandler Me.FormClosing, AddressOf ClaimEditor_FormClosing
    Application.Exit()
End Sub

Answer 6

我遇到了同样的问题，并确定Application.Exit（）正在调用FormClosing事件。只将Application.Exit（）放在FormClosed事件中，而不是FormClosing事件。

使用此代码：

private void frmIMS_FormClosing(object sender, FormClosingEventArgs e)
{
    if (closingPending) return;
    if (MessageBox.Show("This application is closing down because of " + 
e.CloseReason.ToString    () + ". Do you really want to close it ?", ""
, MessageBoxButtons.YesNo) == DialogResult.No)
{                
    e.Cancel = true;
}
else
{
    closingPending = true;
    // Application.Exit(); <-- Remove this

}

private void frmIMS_FormClosing(object sender, FormClosingEventArgs e)
{
    Application.Exit();    <-- Put it here.
}

Answer 7

我认为@ Tornado726已经为所有人提供了最好的答案。但是我猜的只有一个复制/粘贴错误（键入form_closing两次）

Private Sub FORM1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing

    Select Case (MessageBox.Show("Do you really want to close?", "Quit", MessageBoxButtons.YesNo))
        Case MsgBoxResult.No
            e.Cancel = True
    End Select
End Sub

Private Sub FORM1_FormClosed(sender As Object, e As FormClosedEventArgs) Handles MyBase.FormClosed
    Application.Exit()
End Sub

Answer 8

试试这个：这将是一个很好的帮助

   private void Master_FormClosing(object sender, FormClosingEventArgs e)
    {
        DialogResult result = MessageBox.Show("Do you really want to exit the program?", "Data Patch", MessageBoxButtons.YesNo);

        if (result != DialogResult.Yes)
        {
            e.Cancel = true;
        }
    }

Answer 9

Application.Exit()来电frmX_FormClosing()。

这就是FormClosing()被调用两次的原因。

Answer 10

我刚刚遇到同样的问题。这就是我做的事情：

private void frmIMS_FormClosing(object sender, FormClosingEventArgs e)
    {
        if (MessageBox.Show("This application is closing down because of " + e.CloseReason.ToString() + ". Do you really want to close it ?", "", MessageBoxButtons.YesNo) == DialogResult.No)
        {
            e.Cancel = true;
        }
        else
        {
            try
            {
                Environment.Exit(0); // It will try to close your program "the hard way"
            }
            catch (Exception)
            {
                Application.Exit(); // If a Win32 exception occurs, then it will be able to close your program "the normal way"
            }
        }
    }

我确定它会为你工作，如果你还没有找到解决方案，甚至放弃了代码，因为它已经有一段时间了。< / p>

为什么form_closing（）会触发两次？

10 个答案: