I have a very small VS2008 Winforms project that will not start.
When I attempt to start debugging the project, I get the message:
'<form>' is a type in '<project>' and cannot be used in an expression.
From the file .Designer.vb.
The problem is that is indeed a form. If I create a new WinForm and set the startup object to the new form, I get the same message.
When I attempt to check the "Enable application framework" checkbox in the Project properties, I get the message "Startup object must be a form when 'Enable application framework' is checked.
I've tried creating a new project and moving all the code and designer objects to a new form file in the new project, and same result.
Other projects on the same computer run fine.
Any suggestions?
Thanks!
Turns out that the problem was that I didn't have a New() function with no parameters. This is required for VS to see the class as a form.
Related
Okay, in Visual Studio 2012 I have a VB.NET project with originally two forms. Form1 was originally set as the startup form and then obsoleted. Form2 is a nearly identical form that has all of the new desirable functionality.
In my project's settings, Form2 doesn't appear as an available option for Startup Form. (Though it is a normally-created form that inherits Form) After some "troubleshooting," Form1 has been deleted, resulting in the the "Enable Application Framework" option being disabled and no Startup Object being available. When I select anything from the Startup Object drop-down, either Sub Main or Form2, I have an error message stating either "Sub Main not found in Solution" or "Form2 is a type in Solution and cannot be used as an expression" respectively. If I try to enable "Enable Application Framework," I receive an error popup stating "Startup object must be a form when 'Enable application framework' is checked." And Application.Designer.vb is empty.
Some things I've tried:
Clean and Rebuild Solution
Restarting Visual Studio
Temporarily deleting Form1 (it's still excluded from project)
Added a new form, per Neolisk's advice. It appeared in the available objects. I selected it and turned on application framework. From here, I copied the initialization code from Form2's designer code into Form3's. All was alright. Then, I copied Form2's main code into Form3. Now, "Form3 is a type in Solution and cannot be used as an expression" appears in my error list.
With that said, my question is how can I get Visual Studio to recognize my form as a form and set Form2 as the startup object?
add InitializeComponent() in new() function in form2
Found it! The issue was an overload of the form's constructor taking a form as a parameter. Since this was the only constructor in the file, I guess it caused confusion. Commented that out and all was right with the world again.
Sometimes you have a different class name from the form file name.
Check if the class name is listed.
I'm really struggling to find out how to dynamically load a form when starting a VB.NET winforms application in VS2010.
Looking at existing answers such as this: Programmatically change the startup form on application launch?
Has not helped. I do not have a main method (that I can see) in my winforms project and when I go into the project properties I can only select a start-up form. But I have one of two forms to display on start-up depending on the user accessing the application.
I tried to set a loading form up which, in it's load event would call .Show() on the correct loading form after it had determined it and then the loading form would close itself down, but doing this led to both forms being closed.
Below are steps for VS2010 VB.NET Winforms select startup form programmatically.
1 : Go to My project from Solution Explorer
2 : Click on Application Tab--->Uncheck Enable application Framework
3 : Then Inside module create Sub like this
Public Sub Main()
MsgBox("called Main") 'This is testing
Login.Show() 'Set your start up form here
End Sub
4 : Again My Project--->Application Tab--->Startup Object--->Sub Main
5 : Thats it, It will give you message box and will show Login form.
Hope It will help you.
Thanks
Mahesh
Nevermind. I found in the properties a button to generate the MyApplication class in which I can access the startup event.
Another option is to use an MDI form. When it loads you can determine which child form to display.
Using Sub Main is the way I have done this forever but for some reason, MS has decided to make the norm, difficult. To use the Sub Main way, create a "Module" if you dont already have one. Put this code in there:
Sub Main()
Stop
End Sub
Now, in your project properties, assuming your are doing a standard WinForms application, on the "Application" tab, uncheck the "Enable Application Framework". This will allow you to see (and select) "Sub Main" in the "Startup Object" drop-down.
I have a program that has 2 forms (FormLogin, FormMain). When I try to debug I nothing happens and I think it's attempting to go to the incorrect Form. Is there a setting I am missing somewhere?
Go to the Project menu, at the bottom click YourProject Properties...
On the Application tab you will see an entry called Startup Form. From the dropdown you can pick which form is the starting object.
This information is stored in the My Project folder, Application.Designer.vb and Application.myapp files but you should just use the GUI to change the startup form unless you have a good reason to edit the auto generated files directly.
I'm making a VB.net program via a text file and I'm compiling it using vbc.exe via command line. I'm trying to get just a simple program to run in the background of my computer. Problem is, it displays the annoying console window. How do I get nothing to show? No form, no console?
Just use windows forms application don't load the form at all! Just go in project properties and uncheck enable application framework. Now, in the startup object dropdown, select "sub main". Add a module to the project and put a Public Sub Main() in it. You do all the stuff in main() and don't load form at all.
I think you need a form of some kind to keep the message loop going.
Maybe a NotifyIcon type program. It would keep it away from the task bar and desktop areas.
And then customize the NotifyIcon to "Only Show Notifications" from the "Customize" menu for your icon using Windows.
1) Add a module in your project, and create Sub Main
2) Write whatever you want in Sub Main,and MAKE SURE you end it with this statement:
Application.Run()
3) Open properties of your project and choose "Sub Main" as startup object
So , your application will have NO INTERFACE (NO FORM / NOT CONSOLE APPLICATION) and will run from Sub Main(), in addition it will NOT TERMINATE once all the code in Sub Main has executed.Your program will run like a NORMAL windows form application, and will only exit when you want.
Trying to get it to behave like C#, where there is a Program class with a static Main method.
However, in the project properties, I cannot set Program.vb to be the startup object, only the forms (it is a forms application).
Am I missing something?
I am using the VS2010 and the latest VB.
Uncheck Enable Application Framework in Project Properties.
You need to switch off “Application Framework” on the main page of the project settings.
The application framework provides its own entry point which sets up a few things that are subsequently used (e.g. application events, single instance checks etc.) and then just displays the main form using System.Windows.Forms.Application.Run. That’s why you can only supply the main form, not a custom entry point method.