I'm a beginner. I've done a lot of research about Backgroundworker/Multithreading, but I still don't know what to do. My problem is the following:
I have a MENU (Which contains just a collection of colored buttons). When one of them is called (Btn), the button opens a new "UserControl". But it takes a long time to load, so the UI freezes for many seconds. I just want to avoid that. I want to show a Loading CircularProgressBar on top of my MENU while the UserControl loads and keeping the UI responsive during the loading.
The button's code :
Private Sub Btn_Click(sender As Object, e As EventArgs) Handles Btn.Click
MainForm.ShowModalPanel(New UserControl1, DevComponents.DotNetBar.Controls.eSlideSide.Bottom)
End Sub
Thank you in advance.
Related
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.
The VB.Net program I am creating dynamically created Panels within a TableLayoutPanel and adds form elements to them. I need to keep track of what the last of these Panels to have focus was, and am hitting a bit of a brick wall.
I have tried creating an event class for when the Panel has focus:
Private Sub Self_GotFocus(ByVal sender As Object, ByVal e As EventArgs) Handles Me.GotFocus
GlobalController.Focus_Target = Me.Name
End Sub
The classes for each Panel Inherit from Windows.Forms.FlowLayoutPanel, which I why I have the call being Me.GotFocus. Additionally, the GlobalController class is just a class meant to hold global variables for the program.
Now the issue I am having, is that this event only seems to trigger when I actually am deleting the panel. When the panel is created, if I click on it, or any of it's form elements, the event never gets triggered (I debugged the program with a breakpoint).
I can't exactly figure out why this only triggers when I go to delete the panel, and not at any other time. Is there another event I should be using instead of GotFocus?
Use .Enter event in your panel since GotFocus is related only to focused control (not it's parent), mostly when UICues is set.
See MSDN GotFocus
I am making a VB.Net web browser, and to make the whole thing look nice, when the user right clicks, I want a groupbox to show up where the mouse was right clicked. I am using the ChromeWebBrowser.Net project on SourceForge and when I add the following code:
Private Sub ChromeWebBrowser1_MouseUp(sender As Object, e As MouseEventArgs) Handles ChromeWebBrowser1.MouseUp
If e.Button = Windows.Forms.MouseButtons.Right Then
GroupBox1.Location = (e.Location)
GroupBox1.Visible = True
Else
End If
End Sub
It should be working, but when I test it and right click on the web browser control, it does not show up. When I add the same code to the main forms code, it works fine, it just is not working on the browsing control. No errors or anything, it will just not show up. Is there something special I need to do, or can there be a workaround to this?
Thanks so much!
Honestly, this sounds more like you should be using a ContextMenuStrip. You can drop one onto your form(then add items to it), and finally after that you can set the webbrowser's contextmenustrip property to be the one you just designed.
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.
I'm trying to load up a YouTube page using Visual Studio 2008 and a very simple Visual Basic project that contains just a WebBrowser. I want to load the page when the form loads:
Private Sub Form1_Load(ByVal sender As Object,
ByVal e As System.EventArgs) Handles Me.Load
WebBrowser1.Navigate("http://code.google.com/apis/youtube/js_example_1.html")
End Sub
Every now & then (occurs once every 3-5 times, but varies), the form just shows a blank white box.
Could someone help me understand why this happens please.
Edit: This 'freeze' happens for any page, such as http://www.google.com. Is my WebBrowser control broken? Only seems to happen when i place the navigate code in the Form Load event, hmmm strange.
This is probably (almost certainly) happening because a form's Load event occurs before its first Paint event, so once in awhile the WebBrowser finishes navigating to Google (or wherever) before the form paints itself the first time, and thus the WebBrowser shows up as just a white box.
A very simple solution to this problem is to just put a Timer control on the form with a short Interval (say, 100 ms), set Enabled to true, and in its Tick event disable the Timer and then call Navigate(...) on your WebBrowser.