Prevent old form closing until new form opens - vb.net

A very basic/simple question with I'm sure, an even simpler answer, but I just cannot figure it out. I have two forms that a user can switch between using the corresponding menu link on each form. I want to be able to keep the previous form visible on screen until the new form is displayed. In it's current state, the form disappears off screen for around 3/4 of a second before the new one is shown and from a UI/design perspective, I'd like this to stay on screen.
I'm currently using the below code to close and open the forms:
form1.Show()
Me.Close()
form2.Show()
Me.Close
I have tried experimenting with ShowDialog() which does seem to keep it on screen on first run, but clicking back into the form a second time says an error message:
System.InvalidOperationException: 'Form that is already visible cannot be displayed as a modal dialog box. Set the form's visible property to false before calling showDialog.'
Is there a simple line of code to achieve what I want here?

If there is some time consuming code in the Form.Load event (for example, if data is being retrieved from a database) then the following code might help.
Private Sub Form2_Shown(sender As Object, e As EventArgs) Handles Me.Shown
'Assuming default instances
Form1.Close()
End Sub

Posting an answer incase there's an inherit reason this is not best practice or to avoid doing this, but using the below sped it up:
Private Sub menu1_Click(sender As Object, e As EventArgs) Handles menu1.Click
form1.Show()
form1.Refresh()
Me.Close()
End Sub
This was inspired by adding in a Application.DoEvents working, so adjusted the code to avoid that dreaded line.

Related

DataGridView does not automatically appear when form loads

How can I show the datagridview after the form loads?? Because after my form loads my datagridview looks like this. I just want to make my data in the datagridview visible after my form loads. The data appears when I type at the searchbar(not automatic).
enter image description here
Welcome to Stackoverflow!
Firstly, please post the code for your DataGridView, as it is much easier if you provide us code to deal with.
So, let's get this issue fixed.
One problem could be, is that you're making a sub or a function, but you're never calling it.
What I mean by that is, if you create a sub or a function but you never call it, then it won't usually do anything, but for your case, since you want the DataGridView to show on startup (Form_Load), you need to call your sub or function in Form_Load.
So, what I suggest you doing is this:
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
// your code here which would be your sub or function
End Sub
Since you're now calling your sub or function in Form1_Load, your DataGridView will now show on the form when it first loads.
Edit: Changed some text around to make the answer make more sense.

Set Focus to Form After Me.Show

I've come across a peculiar focusing issue. I have created the following "search" program:
It runs in the background.
When you double-tap the Ctrl key it becomes visible.
You can type in the textbox because the form has focus.
If the form loses focus (I click on my desktop, for example), it disappears after 3 seconds.
I double-tap the Ctrl key again, and again it becomes visible.
But this time, no matter what I try, the form is not focused and I cannot type in the textbox without first manually clicking on the form.
What's particularly interesting is that when I run this program in debug mode from Visual Studios, the program regains focus upon double-tapping Ctrl key and becoming visible, and I can immediately start typing in the text box. However, when I build this program and run it alone, the program appears but does not regain focus upon double-tapping Ctrl key, and therefore I cannot type in the text box until I manually click the form.
After Me.Show() I have tried:
Me.Focus()
Me.Validate()
Me.Select()
Textbox1.Select()
Textbox1.Focus()
The form is topmost and normally running in administrator, but the same problem arises regardless.
The issue can be recreated in a more simple manner. Create a form with
Button ("Button1")
TextBox
Two timers ("hideForm", "showForm") both with intervals of 1000
Code:
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
hideForm.Start()
sender.Enabled = False
End Sub
Private Sub hideForm_Tick(sender As Object, e As EventArgs) Handles hideForm.Tick
Me.Hide()
hideForm.Stop()
showForm.Start()
End Sub
Private Sub showForm_Tick(sender As Object, e As EventArgs) Handles showForm.Tick
showForm.Stop()
Me.Show()
Me.Activate()
End Sub
End Class
Click the button, and immediately click on a different window (so the form loses focus). Wait until the form is hidden and shown again. The textbox should have focus. Try typing.
If the program is run in debugging mode in Visual Studios, it works as expected. If you build the program and run it outside of VS, the form will reappear without focus, and you cannot type in the textbox without manually selecting the form.
Sorry for the long-winded explanation. It's a difficult issue to properly describe.
Try the form event handler Activate. Inside that method, you can use setFocus to gain focus for that particular Text Box. I know this answer is too late. But hope this helps someone.
Private Sub Form_Activate()
TextBox1.SetFocus
End Sub
Try an event handler for Form_Activate, and within that handler pass the focus to your textbox.
Instead of Focus, you can also try TextBox1.Select. This SO link provides some additional information and something about the difference between Focus and Select.
Select the Textbox you want to assign a focus to in the Design View Window.
Under the Properties window, set the TabIndex to 0 (zero).
I didn't even have to use the TextBox1.Focus() command. It still bothers me that the TabIndex overrides the Focus command.
What I tried (and worked for me), was to set the Focus() of the Textbox in the event handler Shown() [VB]:
Private Sub Form1_Shown(sender As Object, e As EventArgs) Handles MyBase.Shown
Me.Textbox1.Focus()
End Sub
Note: the Select() method just didn't do the job. I hope this helps anyone else that comes with this same issue.

MessageBox launches but does not display

I'm working on a project and I am using a button to show a message box with sample data.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
MessageBox.Show("hi")
End Sub
Simple enough.
However, when you click the button, I hear the sound that the MessageBox has launched, but the form is never displayed.
I know it has launched because if I try to do anything after clicking the button, I'm locked out. I have to press enter to acknowledge the MessageBox before I can continue.
This project used to display the MessageBox, but it has stopped.
I've tried several different areas in code, but whenever I show a MessageBox, I get the same results. Any ideas on what I have done?
never mind, I solved it.
there was a sub that was rendering a picturebox every time the form_paint was called. It overwrote the messagebox on the screen.

VB using me.close before opening new form

Hi Guys i'm new to Visual Basic Coding, and i can't seem to get where's my mistake on my coding, i'm trying to create a button that opens a new form while closing the current form.
i have two forms, form 1 is MainForm, form 2 is SearchForm
Whenever i use this code:
Private Sub SearchMButton_Click(sender As Object, e As EventArgs) Handles SearchMButton.Click
MainForm.Close()
SearchForm.Show()
End Sub
End Class
it will generate an error and says i need to replace MainForm.Close() into Me.Close()
When i Use this
Private Sub SearchMButton_Click(sender As Object, e As EventArgs) Handles SearchMButton.Click
Me.Close()
SearchForm.Show()
End Sub
End Class
It closes both Forms and it doesn't leave any Form Open. Kindly direct me to the proper path, thanks in advance.
You need to Hide the form rather than closing it. Since it's your main form, when it closes, the application exits.
Standard UI guidelines are to leave the main form open, and open search form on top of that. If you need to block the main form, while search criteria are selected, use .ShowDialog, instead of just .Show.
.NET WinForms programming pattern kind of implies that you never close your main form. If you deviate from this approach, you are guaranteed to encounter all sorts of layout and display issues. So please don't. You can .Hide the main form, if it needs to go to system tray or run in background.

close form when application loses focus

My form is displayed as TopMost on my application. The problem I have is that whenever I minimize my application or it loses focus, the form remains displaying. I want to be able to minimize my application or move to another and also hide or close my form. Once the application regains the focus, then unhide or open the form again.
Here is what I worked out on the form's closing event:
Private Sub frmNavigation_FormClosing(sender As Object, e As FormClosingEventArgs) Handles Me.FormClosing
Static Minimize As Boolean
If Minimize = True Then
e.Cancel = True
Me.Hide()
End If
End Sub
I tried using the same code in the applications WindowDeactivate event but nothing happens.
You do not show how you create the instance of your frmNavigation. I am assuming that you are using the Show Method, so just use the version of Show that you pass in the top level window. That will assign the owner of the form, it will then stay on top of your Main Form and minimize and restore with it also. If this doesn't work please show how you are creating and showing your form.
frmNavigation.Show(Me)
I was able to find an answer to the question. MSDN had an article on this very issue.
it can be found here: http://support.microsoft.com/kb/186908#appliesto