VB app not ending - vb.net

I am using Visual Basic 2010 and I am makeing a simple login app it prompts you for a username and password if it gets it right I want to open a form then close the previus one but when I do me.close it ends the program and I can't go on
I am positive its working because I get the right password and username ut I can't close the first windows
I tried to hide it but when I do I cant close it and the program goes on without quiting and with a hidden form
I heard rumers that there is Sub that can control the x in the corner
if there is one that would probably solve my problem but I can't find it heres the code for the login form
Public Class Main_Login
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If TextBox1.Text = "My Name" And TextBox2.Text = "mypassword" Then
Contentsish.Show()
Me.Hide()
Label3.Hide()
Else
Label3.Show()
End If
End Sub
End Class
Then the Form if you enter the right login info
Public Class Contentsish
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
Label1.Hide()
Timer1.Stop()
End Sub
End Class
how can I fix this problem?

Go into your project settings and set the application to close when the last form closes and not when the startup form closes.
edit: I just checked some of my VB.Net 2k8 code. What I do is create a new instance of the "child" form, do any initialization that I need, call .Show() on it, and then call .Close() on the current form (Me.Close()). Probably not the best way to do things, but it works for me. This is with the project setting I described earlier set. This allows me to exit from the child form or "logout" if needed.

Two other ways you can do this, in addition to Crags:
Load the main form first, then load the password from the main form.
You can use a separate vb module and use the Sub Main for the startup (you specify this in Project Properties, Application, Startup Object), then load the two forms from Sub Main.

So what happens if the login is incorrect? Sounds like you might want to show the login form using ShowDialog, maybe in your Main() before calling Application.Run(new FormMain());

Related

ShowDialog() in vb.net not working properly

I'm not sure if this question has been already posted or not but since I couldn't find the answer I'm looking for so I'll ask anyways.
When I use ShowDialog() to call another form from the current form it just displays the name of the controls the first time it opens, if I close it and open it again then it displays at it should have. For example if I write a simple code as follows
Form1
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Form2.Display("Message")
End Sub
End Class
Form2
Public Class Form2
Public Sub Display(ByVal msg As String)
Me.ShowDialog(Parent)
Label1.Text = msg
End Sub
End Class
When I click the button the first time all I get is "Label1" instead of "Message" displayed on the called form but when I click on the button a second time I get the desired output.
I tried the same thing with Show() and didn't have any such problem. But I need the called form to be modal (like a MessageBox), so is there any other way to do it or can someone tell me the right way to use ShowDialog() ?
I'm new to vb so please keep it simple.
Thanks
ShowDialog is a blocking call. You need to set everything before you call it.

VB.NET - Why is the secondary form closing?

In vb.net, whenever I click my button "ok", it also closes the second form? And please slap me if I have done a school boy error here. I just do not understand what is going on.
Private Sub btOk_Click(sender As System.Object, e As System.EventArgs) Handles btOk.Click
Close()
Dim frmMainScreen As New frmMain
frmMainScreen.Show()
end sub
You first have to show the new form, and then have to close the old form.
Default settings in your application is closing when last form closed. So if you close the actual form (which is the last i think) then your application closes complete.
I agree with #Alex you have to change the project properties (Application Tab => Shutdown mode => Select: "When last form closes") first, but also you need to change your code to be:
Private Sub btOk_Click(sender As System.Object, e As System.EventArgs) Handles btOk.Click
Dim frmMainScreen As New frmMain
frmMainScreen.Show()
Close()
End Sub
Show the second form then close the previous one.

Open Form as ShowDialog But Close Initation Form

Is there any way to do the following, other than hiding then closing the hidden form later?
Mainform opens SecondForm as show dialog, i need to Open ThirdForm from SecondForm while closing SecondForm while keeping third form acting as "showdialog" on the MainForm?
When you show SecondForm(), pass in MainForm() as the owner to ShowDialog():
Public Class MainForm
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim sf As New SecondForm
If sf.ShowDialog(Me) = Windows.Forms.DialogResult.OK Then
' ... do some processing in here ...
End If
End Sub
End Class
Now, in SecondForm(), you can then set the owner of ThirdForm() to that of SecondForm():
Public Class SecondForm
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Me.Hide()
Dim tf As New ThirdForm
tf.ShowDialog(Me.Owner)
Me.DialogResult = Windows.Forms.DialogResult.OK
End Sub
End Class
You could simply open the third form from the main form as soon as the second form returns a dialog result
You also might want to look at MDI this gives you more control over what the user can and can't do.
After trying Idle_mind suggestion it was still giving me problems going back and forth between forms continously showing them as .showdialog. I solved my problem just like tinstaafl suggested. I wish i would have got his message before a couple hours of trying different methods before coming up with this one.
When i close each form, i set a boolean flag in the main form. then i call a sub that is in the main form to show the next form as showdialog from the main form. i use the flag which triggers logic in the form im loading whether or not to bind data from datatable so i can edit it.
sorry with all those forms i know it gets confusing. to sum it up, close the dialog form (me.close), set flag so calling code knows what to do once the showdialog code is satisfied.

Display a modeless Form but only one

VB2010. I must be missing something because I couldn't find a solution after searching for an hour. What I want to do is simple. In my app I want to display a modeless form so that it is floating while the user can still interact with the main form.
dim f as New frmColors
f.Show(Me)
But I only want one instance of the form at any time. So how can I prevent more than once instance being displayed, and if there is one instance then just give it focus?
Does something like this work for you, if the form is already visible you can not do a Show, you can just do a BringToFront, also you can check to see if the Form has been disposed so you can New up another one.
Public Class Form1
Dim f As New frmColors
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
If f.IsDisposed Then f = New frmColors 'To handle user closing form
CheckForm(f)
End Sub
Private Sub CheckForm(frm As Form)
If frm.Visible Then
frm.BringToFront()
Else
frm.Show(Me)
End If
End Sub
End Class
Make your form follow the singleton pattern. I can't vouch for this sample, but from the text it appears to do what you want.

Windows form closing automatically when parent window gets focus

VB Windows form Application.. I am developing an application of which part of the program is around configuration settings allowing the user to enter configuration items. When the menubar item for configuration menu is clicked on the main form the menu opens. This is fine but the mainform should not become active again until the configuration menu has closed. This does not happen right now and the mainform simply comes to the foreground and the configuration form goes to the background... I realize that coding an event on the Child form to handle this would not work because the child window loses control and the main form gains control.. I thought of coding a function as follows on the main form but it does not seem logical because i would have to add to it for everyform and do checking to make sure the child is actually open before trying to close it..
Private Sub Form1_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.GotFocus
MailSettingsWindow.Close()
RentalSettingsWindow.Close()
End Sub
I did away with the above sub routine and used the below code as per the recomendation of using showdialog which works just as i was looking for.
Private Sub MailingAndEmailSettingsToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MailingAndEmailSettingsToolStripMenuItem.Click
Dim MailConfig As New MailSettingsWindow()
MailSettingsWindow.Showdialog()
End Sub
I did away with the above sub routine and used the below code as per the recommendation of using ShowDialog which works just as I was looking for.
My code is as follows:
Private Sub MailingAndEmailSettingsMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) Handles MailingAndEmailSettingsMenuItem.Click
Dim MailConfig As New MailSettingsWindow()
MailSettingsWindow.ShowDialog()
End Sub