I have a large WiseJ vb.net program which has multiple Picturebox controls. An image is loaded into the control on one event, the cursor changes on another etc. Each picturebox use four different events for my functionality. The first picturebox executes the events flawlessly. On the second identically specified picturebox the event handler fails to fire. It won't even execute the breakpoint. I have 8 such picture boxes but only one fires the event handler. I've searched for solutions and tried some but none really address my problem.
I had initially simply copied the working first picturebox code, pasted them, and edited the names to match the next picturebox. This has normally worked well to save time. I then deleted the second picturebox code and went to the page. I double-clicked the offending picture box which generated the click event. The new event still did not fire. I considered a solution which removed the event handler in each picturebox, but frankly, I've added events on pictureboxes so many times and they work fine. I'm guessing something is corrupted behind the scenes but in reviewing the project pages I see no reference to the pictureboxes and am not sure where to look. It's odd that one works fine with all the events but a second fails.
This even works
Private Sub PicFrontLR_Click(sender As Object, e As EventArgs) Handles PicFrontLR.Click
If SpkrDragged = False Then
Cursor = Cursors.Default
LoadSpkrinView(0, "System")
End If
End Sub
This event fails
Private Sub PicFrontC_Click(sender As Object, e As EventArgs) Handles PicFrontC.Click
If SpkrDragged = False Then
Cursor = Cursors.Default
LoadSpkrinView(1, "System")
End If
End Sub
I'm hoping I'm missing something, because one of the solutions involved recreating the page and systematically looking for a failure as I went. This page has a lot of code. Almost done with it and everything else seems to work perfectly.
Well, I figured this one out, mostly. It turns out that a picturebox "apparently" only triggers certain events if there's an image in it. Maybe basic knowledge but I hadn't run into this before. I simply added both a load picture event for the picture box and one for the container. If there's no image the container event fires. If there's an existing picture the picturebox event fires.
One unexplained issue is that the first picture box in a group of eight copied picture boxes, still fires the picturebox event even if there's no picture. As stated the picture box properties are all identical as are the containers. This is what confused me as one event worked and the others did not. Maybe someone can explain.
I was going to build my project when i noticed i didn't put an icon,
and since i couldn't access the icon value of the original form because i used a theme i C+X the container and access it from the grey form, change it, C+V the container, built the project.
Nothing changed, all the name of the buttons and stuff are the same, but i feel like nothing is connected to the code anymore, i don't know what happened, i just recently got re-interested into coding, and i have no idea what to do, i tried some things but nothing worked, so here i am, desperate (i spent 3 days on this, i'm REALLY starting from bottom)
link to the project: http://www.mediafire.com/file/2zrbe32lzpx2qhz/SchedulerProjectVBNET.rar
Thanks in advance
It sounds like you have lost all the Handles clauses off your event handlers. As an example, if you add a Button to your form and double-click it, you will get a Click event handler like this:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Note the Handles clause at the end, which is what connects the code to the event of the control. If you cut that Button from your form to the Clipboard then it no longer exists as part of the form, so that Handles clause will be automatically removed. If you paste the Button back onto the form, the Handles clause is not restored, so the method no longer handles the event.
If that's what has happened - which you can easily check just by looking at the code - then you need to restore all those Handles clauses. You can do that manually, i.e. write them all yourself in the code window, or you can have the designer regenerate them for you. To do the latter, select a control in the designer, open the Properties window, click the Events button, select the desired event and then select the appropriate method from the drop-down list.
Note that you can also double-click an event there to generate a new event handler, which can be useful for handling events other than the default event. You can generate a handler for the default event simply by double-clicking the control.
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.
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.
I've got a multiline textbox and a button below it.
VB.NET, WinForms, .NET 2.0
System.Windows.Forms.Textbox
Multiline = True
AcceptsReturn = True
AcceptsTab = False
CausesValidation = False
No Events explicitly coded.
I'd like the Enter key to insert line-feeds and never move the focus to the next control (the button).
I'd like the Tab key to always move the focus to the next control in the tab order (the button).
What happens instead is that the Enter key inserts one line-feed and then moves focus to the next control (the button). It also does this with Ctrl-Enter, which really baffles me!
By my reading of the help files and extensive googling, it should work the way I need it to.
But obviously I'm missing something. What am I doing wrong?
A method I often use for this sort of problem is to iteratively add and subtract code until I can narrow it down to the one thing that caused the problem.
For instance, you might start by making a very simple project with just one edit box and one other control, and see what it does. If this code behaves the way you want it to, then you can start adding code bit by bit, getting the simple project closer and closer to intended final product, until the bug appears. Then look at the last bit of code you added, and see if you can subtract bits of that until the bug goes away. Iterating this a few times might help you find the culprit.
Alternatively, you could start with your existing (misbehaving) code, and start simplifying it until the bug goes away. Then you add back part of the last thing you deleted, and iterate as above.
Lastly, in this case you could also try adding an event handler for the edit control's Leave event, and put a breakpoint in the handler. When the BP hits, check the callstack and see if you can get an idea of what code precipitated the focus change. For this to work, your debugger will probably need to be configured to display code that you don't have source for (i.e. disable the Just My Code option in the debugger). You could even paste a (trimmed) callstack into the question if you want to get the group's help in deciphering it.
p.s. Does anybody have a name for the iterative debugging method described above? If not, may I propose calling it Newton's Method (or perhaps Newtoning), since it resembles Newton's Method for iteratively finding roots of mathematical functions.
It definitely shouldn't do that. The only thing I can think is it's not got enough height to accomodate multiple lines. Try adding...
textBox1.ScrollBars = ScrollBars.Vertical
If not I don't know. Try creating a blank project and creating a form with one text box, one button set the properties and see what happens...
Turns out that I had forgotten that I had done this (below) elsewhere on the same form:
'http://duncanmackenzie.net/blog/Enter-Instead-of-Tab/default.aspx
Protected Overrides Sub OnKeyUp(ByVal e As System.Windows.Forms.KeyEventArgs)
If e.KeyCode = Keys.Enter Then
e.Handled = True
Me.ProcessTabKey(Not e.Shift)
Else
e.Handled = False
MyBase.OnKeyUp(e)
End If
End Sub