MessageBox with YesNoCancel - No & Cancel triggers same event

问题

I have a message box with the YesNoCancel buttons...

Pressing Yes will do some action and close the application - works fine
Pressing No will do nothing and close the application - (see below)
Pressing Cancel will do nothing and keep the application open - (see below).

I'm using DialogResult.No for the No button and DialogResult.Cancel for the Cancel button. But pressing either of them triggers DialogResult.Cancel event. What's the problem?

回答1:

This should work fine:

Dim result As Integer = MessageBox.Show("message", "caption", MessageBoxButtons.YesNoCancel)
If result = DialogResult.Cancel Then
    MessageBox.Show("Cancel pressed")
ElseIf result = DialogResult.No Then
    MessageBox.Show("No pressed")
ElseIf result = DialogResult.Yes Then
    MessageBox.Show("Yes pressed")
End If

回答2:

I see all the answers are correct. I just want to write a little different piece of code. In my opinion, you may do it without using an extra variable to save the result of the dialogBox. Take a look:

VB Code

Select Case MsgBox("Your Message", MsgBoxStyle.YesNoCancel, "caption")
                    Case MsgBoxResult.Yes
                        MessageBox.Show("Yes button")
                    Case MsgBoxResult.Cancel
                        MessageBox.Show("Cancel button")
                    Case MsgBoxResult.No
                        MessageBox.Show("NO button")
 End Select

C# Code

switch (MessageBox.Show("Message", "caption", MessageBoxButtons.YesNoCancel))
        {
            case DialogResult.Yes: MessageBox.Show("Yes"); break;
            case DialogResult.No: MessageBox.Show("No"); break;
            case DialogResult.Cancel: MessageBox.Show("Cancel");  break;
        }

回答3:

Just to add a bit to Darin's example, the below will show an icon with the boxes. http://msdn.microsoft.com/en-us/library/system.windows.forms.messagebox(v=vs.110).aspx

Dim result = MessageBox.Show("Message To Display", "MessageBox Title", MessageBoxButtons.YesNoCancel, MessageBoxIcon.Question)

If result = DialogResult.Cancel Then

    MessageBox.Show("Cancel Button Pressed", "MessageBox Title",MessageBoxButtons.OK , MessageBoxIcon.Exclamation)

ElseIf result = DialogResult.No Then

    MessageBox.Show("No Button Pressed", "MessageBox Title", MessageBoxButtons.OK, MessageBoxIcon.Error)

ElseIf result = DialogResult.Yes Then

    MessageBox.Show("Yes Button Pressed", "MessageBox Title", MessageBoxButtons.OK, MessageBoxIcon.Information)

End If

回答4:

dim result as dialogresult
result = MessageBox.Show("message", "caption", MessageBoxButtons.YesNoCancel)
If result = DialogResult.Cancel Then
    MessageBox.Show("Cancel pressed")
ElseIf result = DialogResult.No Then
    MessageBox.Show("No pressed")
ElseIf result = DialogResult.Yes Then
    MessageBox.Show("Yes pressed")
End If

回答5:

Use:

Dim n As String = MsgBox("Do you really want to exit?", MsgBoxStyle.YesNo, "Confirmation Dialog Box")
If n = vbYes Then
    MsgBox("Current Form is closed....")
    Me.Close() 'Current Form Closed
    Yogi_Cottex.Show() 'Form Name.show()
End If

回答6:

Closing conformation alert:

Private Sub cmd_exit_click()

    ' By clicking on the button the MsgBox will appear
    If MsgBox("Are you sure want to exit now?", MsgBoxStyle.YesNo, "closing warning") = MsgBoxResult.Yes Then ' If you select yes in the MsgBox then it will close the window
               Me.Close() ' Close the window
    Else
        ' Will not close the application
    End If
End Sub

回答7:

The way I use a yes/no prompt is:

If MsgBox("Are you sure?", MsgBoxStyle.YesNo) <> MsgBoxResults.Yes Then
    Exit Sub
End If

回答8:

This is how you can do it without a Dim, using MessageBox.Show instead of MsgBox. This is in my opinion the cleanest way of writing it!

Select Case MessageBox.Show("Message", "Title", MessageBoxButtons.YesNo)
    Case vbYes
        ' Other Code goes here
    Case vbNo
        ' Other Code goes here
End Select

You can shorten it down even further by using If:

If MessageBox.Show("Message", "Title", MessageBoxButtons.YesNo) = vbYes Then
    ' Other Code goes here
End If

回答9:

Try this

MsgBox("Are you sure want to Exit", MsgBoxStyle.YesNo, "")
                If True Then
                    End
                End If

来源：https://stackoverflow.com/questions/2256909/messagebox-with-yesnocancel-no-cancel-triggers-same-event

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