We have a huge application that runs through a mass of code for every click you do. In one specific case, where you have a specific control in plain sight (so that the events are firing) and you load some special data into it and then click on the new button the form loses some events, like the closing event (you cannot close the form anymore and stop points in debug mode are not triggered) and one validating of a ComboBox that is really needed for the program. The only thing you can do when you get this kind of error is to restart the application to get out of this subform. But I tested it for 2 days now and even when I activate all points in the 'Exception Settings' I don't get any exceptions. The form (and other controls) are not losing ALL events. The resize, for example, still works. Even a specifically called AddHandler is not firing. Can you iterate somehow through the EventHandlerList? Or is there any way to test WHERE the event dies? Somehow any ideas on how to debug such a problem?
I'm not even sure how to ask this question, but here goes. The design view of my windows forms object now crashes with the following error:
The control DevComponents.DotNetBar.Office2007RibbonForm has thrown an unhandled exception in the designer and has been disabled.
Exception: Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index
Stack trace:
at DevComponents.DotNetBar.Office2007RibbonForm.WindowsMessageStyleChanged(Message&
m)
at
DevComponents.DotNetBar.Office2007RibbonForm.WndProc(Message & m)
When the error page pops up, it is this:
I can't think of anything I did before this happened, which is very frustrating. The last thing I did was this:
Add Button on Ribbon Control
Double-Clicked the button to add code
Realized I forgot to name the button, so removed the event code
clicked back on the form tab and BAM. Error.
I tried the following to fix:
Went back and did an undo on the code (re-added the event for that button). But didn't help.
Edited the Designer.vb file to remove that button entirely. Still didn't help.
I thought about pasting my designer code here... I will if that makes sense, but it is so huge I wasn't sure if that was worthwhile. Maybe the above error makes sense to someone besides me???
**** EDIT: Forgot to mention the application runs fine. Just can't edit the form anymore.
OK. I found it. For some reason the form duplicated the style on the ribbon control. Even though the error didn't seem like that one.
FYI - I just kept commenting out stuff in the designer and then trying to launch the form until the error went away. When I finally got to the ribboncontrol, I saw that there were 2 statements:
'Me.RibbonControl1.Office2007ColorTable = DevComponents.DotNetBar.Rendering.eOffice2007ColorScheme.Silver
and
Me.RibbonControl1.Style = DevComponents.DotNetBar.eDotNetBarStyle.StyleManagerControlled
As you can see, I commented out the first one and everything worked.
I have a program where I need to do some initial work before calling the form, so I disabled the Application Framework setting and wrote my own Main function with a call to Application.Run(myForm) when it's time to run the form.
Everything was working fine, no problems, but now I have need of some other service before opening the form. Rather than add all that code to this program, it has all been moved into its own executable. This second program can edit files that the first program will use, so I need the first program to wait so that it will read up those changes (should they be made). I suppose could just as easily use the Shell function, but for various reasons I'm creating my own Process object and calling it/waiting on it through that.
Anyway, I make this call to the second program some time before the Application.Run call. The first program waits its turn, and I can interact with the second program successfully, no trouble at all. But when it's done, the window for the first program is hidden behind any other windows that are on the screen. This doesn't happen in XP, only in Vista (and maybe 7, but I haven't confirmed yet). I've already tried manually forcing the form to appear in front, minimize then maximize, get focus, etc, but nothing brings it to the front unless the user manually clicks on it with the mouse.
What am I doing wrong? Why does this behavior occur? I know it has something to do with waiting for the executable to finish, because if I don't force the first program to wait everything is fine (other than it not waiting). I can circumvent the issue by calling the second program in the Load event of the form, but then I have to read the file a second time to catch the changes instead of reading it once, and it also looks bad because the form is being drawn really slowly while the second program is sitting there.
If anyone has any input, I'd appreciate it.
This isn't really an answer to why you're experiencing this behaviour, but a simple workaround would be to temporarily set the form's TopMost property to True in the load event. Then, depending on how intrusive you want that to be, you could either reset it under a short timer or wait for say the MouseEnter event to fire.
There are another topic in this site about that, but I not got the link. This problem seems be a bug into .NET framework. The API below (VB.NET example) works for me in windows XP and 8.1. Don't tested in other versions of Windows.
<Runtime.InteropServices.DllImport("user32")> _
Public Shared Function SetForegroundWindow(hwnd As IntPtr) As Integer
End Function
Private Sub Form_Load(sender As Object, e As EventArgs) Handles Me.Load
SetForegroundWindow(Handle)
End Sub
This is an IDE question for Visual Basic 2008 Express Edition. It might be a bug in the IDE, or maybe it's my fault somehow?
My main form is named frmMain and in my application's properties I have set frmMain as my startup object. All of that seems like what a lot of software engineers do.
But while debugging I hit Ctrl + Break, as I have done for years, and I get an behavior in the IDE that I wasn't expecting. Upon doing so, I get the green background text and the green arrow indicating in a tooltip:
This is the next statement to execute when this thread returns from the current function.
Even if I didn't have the designer document open, it automatically opens frmMain.Designer.vb in the editor and hihglights line in green. The line is of course: Partial Class frmMain which is line 2 of the file. (Yes, it's highlighting the second line of the designer-generated code.)
frmMain seems to have fully loaded and it's my startup object. As far as I know, there shouldn't be a "next statement to execute" at all because code should be idle. I don't want to see the Designer.vb document... I want to edit my own code.
What's causing this? Even though my form is behaving just fine, could there somehow be an unfinished aspect of loading the form such that it is "not returning" from a function?
The Visual Basic compiler will add an entry point in your form. The entry point is the standard main function or "shared sub main", which in turn contains the code "application.run(new form)". Since this is compiler generated code there is no source location, so the Visual Basic editor highlights the class definition.
The clue to this is in the call stack. Notice the Main().
Shared Sub Main()
Application.Run(new frmMain)
End Sub
I found the answer on my own:
I checked the "Enable application framework" checkbox in the solution's properties, and all is well!
I believe this issue arose when I was working on experimental code in which I had desired to make Sub Main my startup object. I had cleared the checkbox because doing so is necessary to use Sub Main.
When the experiment didn't pan out I reset the startup object back to frmMain, and my app worked fine. However I had not re-checked the box. I hadn't noticed the change in the IDE behavior for several days (when I needed the more standard behavior) so I had not observed any correlation.
Although checking that box is definitely the solution, it's still not exactly clear to me is what the heck this box actually does, other than cause me to spend a lot of time on StackOverflow.com! ;-)
To others who encounter a similar situation, I'm now quite confident that my settings were not corrupt, and if you're using the Express edition, please don't be mislead by MS documentation which may lead you to believe it's the "Just My Code" option. This option cannot be changed in the Express versions. (But it's not because you can't turn it on -- It's because you can't turn it OFF in Express!)
Thanks to everyone for your efforts.
I'm going to guess that it is trying to show you the equivalent of:
Application.Run(new frmMain)
This is the code that gets generated to startup your form. But in VB.NET this code gets burried. Create a Main() function and change your startup type to that with this line in it and repeat the process. You'll see it highlight Application.Run. That is the method that contains your Windows message pump loop.
I fear that there is something obviously wrong with my code, but I have come across a situation where the Form.Load event is not firing when I create and show my form.
The form is not subclassed (as I've seen some problems with that in some searches), and I am not getting any errors thrown when I step through the code in the debugger.
I have a break point set on the IDE-created form load function (which does have the Handles MyBase.Load signature suffix) but the breakpoint is never reached and the form does display and work.
The form is passed three arguments in the constructor but the IntializeComponent() function is called before anything else is done.
Code:
Public Sub New(ByVal argA As Object, ByVal argB As Object, ByVal mode As FormMode)
' This call is required by the Windows Form Designer.
InitializeComponent()
' Other code here,
' No errors generated
'
End Sub
The form load function is as follows, (but this is never actually executed as the event is not fired).
Code:
Private Sub frmInstrumentEditor_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
If Not argA Is Nothing Then ' argA set in constructor
' Operations using argA
End If
End Sub
I might add I am using some databinding with some controls and the argA object, but if this was producing an error I thought I would have seen this (I have CLR Execpetions settings set to Thown in the debugger > exceptions window)
Any ideas why this might be occurring?
I just had a similar issue (it was in Shown event, not Load, but the root cause is the same). The reason was hidden deep in one of the ancestors - there was an unhandled NullReferenceException thrown and this exception was somehow "muted".
I found it after extensive debugging with F11.
But... when writing this answer I found this post on SO
Just add Application.SetUnhandledExceptionMode(UnhandledExceptionMode.CatchException) in your Main() method.
If you're using a 64-bit machine, it provides you with the solution (it worked in my case, too).
I had a similar problem. On opening the form for the first time, the load event would not be tiggered but on opening it the second time, all would be well. The problem tuned out to be one of my text boxes which was bound to a field that I had deleted from the database (sql server - I was using datasets, tableadaptors and bindingsources in a fairly standard way).
Make sure that all the controls on your form that are databound have fields that exist in the dataset and that the dataset is an accurate reflection of the underlying database table (the easiest was to do this last bit is to use the "Configure data source with wizzard" button on the data sources window (menu -data - show data sources) and remove the table. Then use it again to add the table back- this should make sure all the data matches.
Hope this helps.
OK I had the SAME problem (I think) and the clues here helped. It was databinding (sort of)
I had properties of some controls bound to settings and when I delete these settings the form load event stopped running. Removed the bindings and now it is running again.
Here is another idea.
What happens if you set all exception types (not just for the CLR) to be thrown instead of user-unhandled. Does the application break anywhere at all?
Also, just to double check, you are in debug mode right?
The problem you are experiencing may be caused by the application needing to fully load the form before you can do the "other code." This could be due to the other code dealing with objects on the form that haven't finished loading. You could use a timer that gets enabled in the load function to execute the other code. This way you don't have any timing issues and you can first load the form, and then a split second later, run the code you want from the timer.
Is your windows form inheriting from a base page? If so, the base page probably also has a Form Load event handler. In that base page Form Load event handler you will probably find an exception that is being thrown. So it is exiting the base page form load event handler and not firing the form load event handler in your inherited windows form.
I had a similar issue, the problem was a mistake in the databinding. Omit the code for databinding and give it a try. I think the load event handler will be hit. Then see what's wrong with the databinding part.
Had the same problem. Checked my data bindings, everything looked ok. Got to thinking, even though form was closed, maybe .NET wasn't sure (old days, sometimes forms were only hidden and not really closed).
I added the event handler FormClosed and put a single line in it:
Private Sub frmScheduleInquiry_FormClosed(sender As Object, e As System.Windows.Forms.FormClosedEventArgs) Handles Me.FormClosed
Me.Dispose()
End Sub
Problem solved!
Solved....
Have spent 4 hours and finally got clues from this answers.
in my case i was having couple of TextBox control on the form bound to a BindingSource with respective column, i still have that bindingsource on the form but what was happened that i deleted one column from underlying database table so on the form there is still one TextBox exist pointing to that column with bindingsource, in fact there is no column like that because i deleted !..... this lead Form.load event was not firing ........finally fixed..
thanks to all of you ..
I had the exact same problem just happen to me. Turns out I had added some ApplicationsSettings properties to a form TextBox control, but later wanted to delete them. I thought I had cleared everything out, but obviously I didn't - and this was what caused the Form_Load() (and maybe other events as well) to not fire. Deleting and then re-adding the offending TextBox did the trick.
Hope this helps
Matt is probably right about this one. Have you tried adjusting your code like this:
Private Sub frmInstrumentEditor_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
If Not argA Is Nothing Then ' argA set in constructor
' Operations using argA
Else
MessageBox.Show("argA has not been set")
End If
End Sub
If the messagebox appears it means that the event is fired before your argument is initialized. It would also account for the 'strange' behaviour concerning closing/opening the form.
Have you tried running the argA operations in the 'Shown' event?
Not sure if this will help, but I just ran into this issue because somebody mistakenly deleted the Handles Me.Load. I see you show MyBase.Load try changing it to Me.Load.
I had a similar issue. It turned out that I was not using the Show method on the form - instead using a user32.dll ShowWindow call. This means the form still appeared, but the Load event was never fired because the dotNet Show method was never called.
I know that this is an old post, but I thought that if someone was searching this issue, that my fix to this problem might help.
I was having this same problem as stated in the originally posted question, but I didn't have any data bound fields on the form. I found that the problem was in the fact that I was using the CurrentDeployment.CurrentVersion method and it was causing the silent problem. I set the application from debug mode to release and the problem still existed. Through trial and error I remarked out the defining method Dim xVersion As Version = ApplicationDeployment.CurrentDeployment.CurrentVersion
and presto... its now working as usual.
I ended up changing the orginal code the code below.
Dim xVersion As Version = ApplicationDeployment.CurrentDeployment.CurrentVersion
sysVersion = String.Format("{0}.{1}{2}.{3}", xVersion.Major, xVersion.Minor, xVersion.Build, xVersion.Revision)
New code
#If (DEBUG) Then
sysVersion = "[Debug mode]"
#Else
Dim xVersion As Version = ApplicationDeployment.CurrentDeployment.CurrentVersion
sysVersion = String.Format("{0}.{1}{2}.{3}", xVersion.Major, xVersion.Minor, xVersion.Build, xVersion.Revision)
#End If
I hope this helps someone.
Happy Coding...
Same problem, I rewrote the designer and that fixed it. The designer was loading then crashing (silently of course), and form_load was not firing due to that.
Had same issue, but cause was totally different.
Form was being shown using form.Show() instead of form.ShowDialog()
I experienced this symptom when building and running a .NET 4.0 WinForms application which loaded a series of older assemblies (.NET 2.0; .NET 1.1).
In the past I had seen this cause a mixed-mode assembly exception. In this particular case, the main Form loaded without exception and without executing any of its Form Load code.
The solution, in my case, was to set useLegacyV2RuntimeActivationPolicy="true" in the App.config document.
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
</startup>
Make sure your "Solution Configuration" box at the top of your IDE is showing "Debug".
I found that if it showed "Release" the "Load" method was not captured by the debugger.
In my case, the main form had WindowState: Maximized set in the designer. This was causing the window to be drawn on screen prior to the Load event firing.