How to close the former form?

How to close the former form?

• asbuilts

  Hi David,

  just a short query with regard of your suggested code to display login form from MDI Parent form and not vice verse.

  Did i understood you correctly that to build modal Login form, one should add in MDIParent.Designer.vb the following lines of code:

  Dim loginForm As New fclsLogin()

  loginForm.ShowDialog()

  I tried this code and it works well in the run time. The login form shows first and after authentication on ok_click event it closes and opens MDI Parent and child forms. Saying this i have also to point that every time after debugging when i press on view MDIParent Design, it returns en error-warning:

  Warning 1 Form that is already visible cannot be displayed as a modal dialog box. Set the form's visible property to false before calling showDialog. C:\ModellingFM\Examples\Ch17\APITotal\ParentForm\MDIParent1.Designer.vb 365 0
  

  I was trying to find in properties section of both login form and main form the visible property but it can't be find. Can you please tell me if this warning can affect the application deployment.

  
  
  

• sagan69

  Try Form.Hide(). This may not be the most elegant of solutions.
  
  By the way, why is close() not working

  
  

• Fulankazu

  Hello Joey,

  Do you really close your loginform or just hide it And on which form is the MessageLoop running (search for Application.Run)

  Greetings from the rainy Netherlands.

  
  
  

• RalphTrent

  Instead of trying to dispose of the form in the constructor (bad idea), set a flag and call MainForm.Close in the Load event
  
  

• Beverley

  since me.close() will close both login and main form , i do not know the reason
  

• dmkp231

  You should not have your Login form as the first form, you should have the MainForm as the first form, then from MainForm you can add code to create this Login form from the InitializeComponent and from the login form you can then have a event handler to close the login form after user successfully login.
  
  Sample code
  
  In the MainForm
  
  Private Sub InitializeComponent()
          components = New System.ComponentModel.Container()
          mainMenu1 = New System.Windows.Forms.MainMenu()

          Me.Menu = mainMenu1
          Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Dpi
          Me.Text = "Form1"
          Me.AutoScroll = True

          Dim loginForm As New LoginForm()
          loginForm.ShowDialog()

  End Sub
  
  In the LoginForm add the following event handler
  
  
  Private Sub Login_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Login.Click
          'Do login verification
          Me.Close()
  End Sub
  
  
  David

  
  
  

• TLJ

  Hi David,

  I tried your suggestion to close the login form. But when Login form is closed, the MainForm shows up. Could you give me some help Thank you so much.

  -Joey

  
  

• TommyKohler

  Thank you Alex!
  
  Here is my solution of the problem:
  
  

  private void MainForm_Load(object sender, EventArgs e) {      if (Thread.CurrentPrincipal.Identity.IsAuthenticated == false)      {           this.Dispose();      } }

  
  

• baldrick98007

  Hello David,
  I've translated your VB code to C# for my needs. The login functionality works correctly.
  
  Well, I wanted to give the user an option to close the login form and exit the application, so I added a new, second button named "Cancel", next to my "Login" button. The button2_Click method is placed at the login form file, whitch is Form1.cs for me. At the MainForm.cs I've tryed any combination of:
  
  

  components.Dispose();
  Me.Dispose();
  
  

  public MainForm() {     InitializeComponent();     components = new System.ComponentModel.Container();     MainMenu Me = new System.Windows.Forms.MainMenu();     Form1 loginForm = new Form1();     loginForm.ShowDialog();    if (Thread.CurrentPrincipal.Identity.IsAuthenticated != true)    {       components.Dispose();       Me.Dispose();    } }

  
  
  What I got as a result was: login form is closed and the MainForm is started.
  
  How to make the login form (and the entire application) to be closed, and not the MainForm to be started

  
  
• How to close the former form?