Exceptions In Form Load Event Do Not Get Thrown On Vista
Sep 23, 2009
I'm using Vista Ultimate x64 to develop on and I have found that any unhandled exceptions that I would expect to get thrown in the Load event of a form do not actually get thrown... This happens no matter which compile mode I select (x86, x64 or AnyCPU). If I copy the exact same EXE to an XP machine then the unhandled exception is thrown as expected and the JIT debugger warning message appears. Its very annoying as absolutely no indication that an exception has occurred is shown, the program just loads normally but anything after where the exception should have been thrown is not executed. For example, if I create a new project now and stick this in the form load event then the program would just load as if nothing has gone wrong:
My.Computer.FileSystem.ReadAllText("----")
What types of exceptions should be thrown for invalid or unexpected parameters in .NET? When would I choose one instead of another?
Follow-up:
Which exception would you use if you have a function expecting an integer corresponding to a month and you passed in '42'? Would this fall into the "out of range" category even though it's not a collection?
I've a control that throws an exception in one of its events and I need to catch this exception. How can I do this?
Example: Private Sub AxNtlxImage_Reason(ByVal sender As Object, ByVal e As AxNTLXIMAGELib._DNtlxImageEvents_ReasonEvent) Handles AxNtlxImage.Reason ' TODO: Deal with this reason message Throw New ArgumentException(e.sText) End Sub
I want to catch this exception from another procedure when it happens.
I have a form where it is validating three fields. I want to have it so if an exception has been thrown in any of the three fields that the code that is in the button does not run and it redoes the validation.
I am using VB.NET for Windows applications. What is the difference between Load event,Activate event and Enter event in the Form and in which order the above event is executed.
I'm trying to execute different code depending on the button clicked (button 4 or 5) on Form1, but when I click on button5 to activitae the code on the Form2's Load event everything is Ok, but when I click the back button to return to Form 1 and click on the Button4 to activate the code on the Form2's Load event again, it doesn't active the Form's Load event, is there a way to form the form load event every time I access it from Form1? [code]
I have two forms. Form A and Form B. Form A has a datagrid that is populated from a SQL Database Table query. When a button is pressed Form B is launched that allows you to add a record to the database table. I need for the datagrid to be refreshed and show the newly added record when I close form B and go back to the parent.
ll app build in VB 2005 that has a DLL. The app runs fine on 32bit systems but fails on 64-bit ones (Failed to load the assembly: BadImageFormat from the DLL). As I could not fix the problem I wish to somehow ignore this error so the rest of the app can run normally. I wish to retain the funcionality on 32-bit systems thus not removing the DLL from the project.
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.
I want one form frmFrontEnd to be the base of my application, so when i press F5 it is the first to 'open/be seen' and then from here using previous i want other forms to open. How can i set frmFrontEnd in the form load event to be the parent form? If you're not living on the edge, you're taking up too much room
I have a form and initialize some global variables on its Load Event. There is a TextChanged event in one control (a textbox) that uses that value. The TextChanged event of the control is triggered before the Form's Load event even if I do not change anything on the TextBox, it looks like that happens when the control is loaded. Why is it doing it before the form? and what event can I trap in order to assure it's the first thing that happens?
Its as simple as this:
vb.net Private Sub PackOutMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load ActiveFlag = False
[Code]....
My guess is that the msgbox should not appear until the flag is set to true somewhere in the code and then change the contents of txtUser, but it is shown before the form.
How can I catch an exception thrown by a control event?I have a control that throws an exception in one of its events and I need to catch it but I don't know how.Consider for example that the text box control throws an exception in its click event. How can I catch such exception?
I am writing a program in vb.net I have to call an exe(printstatus.exe) in form load event. I successfully called exe. But I don't know how to kill that exe (printstatus.exe) when an user is logged out.
I was having a problem with the debugger not stopping at breakpoints. After a lot of work that yielded no results, I realized that the problem was occuring in the form's load event and subs called from that event.
The problem is that it appears that the load event is not being called. Other startup forms in other projects in the solution seem to be working ok.
what could be keeping the the Load event from working?
I have the following code in the Load event of my form and the 3rd statement obviously fails. My question, why does the code fail and not tell me about it? In other words, it fails and then simply displays the form without crashing. It also doesn't execute my 4th statement.[code]...
Try Dim username as String = My.Application.CommandLineArgs(0) Dim password as String = My.Application.CommandLineArgs(1) Catch Msgbox("Cannot launch") Application.Exit Exit Sub End Try
I placed this in the form's load event. What I want is for this check to run before the form even loads.If an error occurs, the msgbox comes up and the form is never seen. When I try the code now, the form comes up the msgbox shows. When the user clicks OK the form closes. I tried placing it in the form's designer but the designer tries loading the form any way. How do I get this check to run before the form shows?
I am making the Transition to VB.Net (using VB.NET 2010 express) and I have a simple problem that is driving me crazy. I wish for my Form when it Loads, initialise and then call a sub and do some stuff eg perform a plot. If i place a button on the form and click it the sub works fine.This task was simple to do in VB6 but for the life of me I cannot get it to work in VB.NET. Has the Form-Load event changed in some way with .Net?
I have a calculation project with 6 forms. The last form shows all the input and output data from the previous forms. This is accomplished in form6 load event. Form6 contains about 40 controls (mostly textboxes, labels and few pictureboxes), populated in this way:Textbox1.Text = Form2.Textbox3.Text, etc.I am not sure if this is a good practice. I know I can use the DGV, but it does not suit me because of the graphical reasons.
I have one form (FormA) that fills a combobox with data when the on-load event is trigged.In that combobox, I can select "New value" which opens another form (FormB) on top of FormA.On FormB I add the new data and saves them to a Database.Everything OK till here.I then close FormB.... and return my attention back to FormA.Now I would like to reload data into the combobox, but everyway I have tried, it will not work.
I am been working on an a small app that has a Forms.Webbrowser control that navigates to a Adobe Flash program. I have developed the app on Vista 32bit platform and have had no problems. I have sent the app to a couple of people to test out and one is using Vista 64bit and is running into a problem. I know the webbrowser control just uses the underlying base framework of IE. The problem on the 64 bit machine is when the site is navigated to it says that it needs to have Flash installed. When the user goes to Adobe's site it says they need to use a 32bit browser.
As stated on Adobe site here:[URL] the Flash player need to be in a 32 bit browser. What options do I have to be able fix this problem? Is there another control that I can use that would be the same in a 32bit platform and 64bit platform? Besides navigating to the Flash program, the browser also goes to standard web pages.
I have two forms , first one is search and second is showing the data searched by first form search criteria. When the search query runs it takes lot of sql server resources, so I have passed that query to second form, it searches in database and shows the results. But if the results are not found I wish to close the second form in Form load event. As Second forms form load event searches for the record. I tried to use SecondForm.close in SecondForm.load event but failed to do so.
I want to develop a program using VS 2010 Pro, VB and .NET 4.0 to run on a Windows standalone computer.The program will be loaded by another program that checks for a text file in a directory.When that file exists, the program I want to develop will be started and it will process the text file.The new program will not have any buttons or dialog boxes, it will simply display the progress of the processing of the text file and then it will simply terminate and exit.
I know I can start the processing by putting code in the LOAD event for the form, but i want to make a new class for all the processing to start from and have the new class perform all of the steps necessary to complete the processing of the text file.Of course this new class will use other classes to do all of the different processing steps.How do I execute that new class from the Form LOAD event?
What I have found is that ifAutoscalemode is set to DPI or Font, the form Load event is raised during the form constructor (sub New). When autoscaling is not active, the form Load event is not raised until the form is displayed (Show method).This change of event sequences caused various errors from code I had in the Load event for various forms because the controls on the forms weren't completely initialized. I have worked around the errors for the most part so it isn't much of a problem anymore but it is forcing me to change some coding habits (maybe not good habits) that I have been doing for years.
In my form.load event, there is a bindingsource.fill event.After the .fill, there are two or three other lines of code that query the newly filled tablemanager. The code gets the number of total records and displays that number on the form.Here is the problem ....When the .fill statement is executed, control reverts to the form and any statement AFTER the .fill event is not executed.I have tried to stick the remaining lines of code into some other form event with little success. These three lines of code only need to run once.Does anyone have a suggestion as to where to stick these lines?
Private Sub SCDBEditWindow_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 'TODO: This line of code loads data into the 'SCDBDataDataSet.StampCollection' table. You can move, or remove it, as needed.
