i've already searched and seen almost all in the web and in the forum, but i can't deal with that.
What I'm trying to do is to obtain an installer and then an exe of my form application by using c# in visual studio 2019.
So, i've followed that tutorial:
https://www.youtube.com/watch?v=fehVTLNQorQ&ab_channel=FoxLearn
so i correctly obtain the setup file. Then, when i launch it, it installs and if i try to run it i get that error: "You're trying to open a file type system .dll"
What i'm doing wrong?
I also structured my main class as in that response:
Changing a source file to compile Main() method in a project, in VS c# console application
I also used that suggested setting (sorry for non english language but it's quite understandable):
Is there somebody that can help me? thanks a lot
Some things you may want to check:
If you have more than one project in your solution, make sure that the main project is marked as Start-up project. On the solution explorer, right- click on the main project and select "Set as start-up project".
If you only have one project in your solution, check that no .exe is being produced in the corresponding bin folder. If it is, go to your project properties, inside Debug, and make sure that the option "Start project" is selected. You can also try to select the option "Start external program" and browse to the .exe in your bin folder (although the result should be the same).
If no .exe is produced, you may want to have a look at this post. It is similar to you problem I think but the other way round. I looks that the UseAppHost should be True for your case
You have to choose "Publish Items" and not "Primary Output" when you add a "Project Output" in "Application Folder" for .Net Core 3.1 in the setup project created by Visual Studio Installer Projects Extension.
# Alessio Orlando.
Based on my test, there is a different step between adding different project to the installer.
For WPF App(.NET Framework) project and Windows Forms App(.NET Framework) project: You could choose Primary output when you add a "Project output" in "Application Folder" in the setup project.
For WPF Application(.NET Core) project and Windows Forms App: As gigiabbrescia said, you have to choose Publish Items when you add a "Project Output" in "Application Folder" in the setup project.
Finally, there will be an .exe file in your installation directory after installing your Setup (Like the picture below). And you could click on your .exe file to run the program.
This question already has answers here:
Can't run program because it asks me to attach on process
(5 answers)
Closed 2 years ago.
I'm new to C# and using Visual Studio 2019 to learn C#.
Now after I create a new project I cannot run and debug it. The code is very simple.
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But the start debugging is dark. Also, I found there is no project in the solution.
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I just find that when I create a new project, something is missing in the project folder.
enter image description here
When I want to open the .csproj file, it gives me a prompt: unable to locate the .NET SDK.
Really appreciate someone who can point out what should I do or give any clues.
You have a single .cs file open. To compile it into an application, create a "New Console Project" in Visual Studio and copy this code into the resulting Program.cs. In the future, open up the *.csproj or *.sln files to work with the project, not just the individual .cs file. Good luck!
This question already has answers here:
Copy exe from one project to another's debug output directory
(2 answers)
Closed 5 years ago.
I have a C# solution (visual studio 2017) with two projects lets say A and B, both compiled to exe. Project A depends on project B's exe, I though a dependency to project B would solve this. However, the exe doesn't get copied automatically when build.
Does the dependencies not work for exe's ? Is the only solution to make an post build step ?
I think you want a post-build event.
It sounds like you already have the Project Dependency set up, which is good, because it's important that Project B gets built before Project A. And adding a Project Dependency for Project B, to Project A, is the way to do that.
Here's the documentation for adding/removing Project Dependencies: https://msdn.microsoft.com/en-us/library/et61xzb3.aspx
In Project A you can add a post build event that will copy the Project B exe.
Right Click Project A, and choose "Properties".
Change to the "Build Events" tab.
Add the command: copy "FromPath" "ToPath"
The documentation for the copy command is here: https://technet.microsoft.com/en-gb/library/bb490886.aspx?f=255&MSPPError=-2147217396
If you click "Edit Post-build", you'll get a mini-editor which has a button labelled "Macros".
If you click that "Macros" button then it'll allow you to insert replacement strings in the format $(foo).
These macros allow you to get things like the project or solution folder, so you can easily build paths that point to the right places.
Here's some documentation on the build events: https://learn.microsoft.com/en-us/visualstudio/ide/how-to-specify-build-events-csharp
Here's some (crappy) documentation on the Build Events properties page: https://learn.microsoft.com/en-us/visualstudio/ide/reference/build-events-page-project-designer-csharp
Here's some (useful) documentation on the macros: https://msdn.microsoft.com/en-us/library/c02as0cs.aspx
Have a look at the Properties of your dependencies and set "Local Copy" for your exe, this should copy the exe to your A.exe's bin folder.
Edit:
It's the german version, but should look like this:
You can use the Post-build events ( Project properties -> Build Events ) to copy the file at the end of build.
I have an ASP.NET project with outputType library, I need to run the project but it's not running. what outputType should i use to make my project run?
In order to fix the above error, right click the Solution name in Visual
Studio 2005/2008 and select Set as StartUp Project option from the popup menu.
source : Fix: A project with an Output type of Class Library cannot be started directly
Despite ASP.NET projects have Class Library type, Visual Studio can "run" these types of projects(it deploys project's output to IIS or dev server and starts web-app).
So to solve your problem you should tell Visual Studio somehow that your project is ASP.NET project. I see to ways:
1-st one - fast, straighforward, dumb, but reliable: create new "ASP.NET Web Application" project in visual studio and copy all sources to it.
2-nd - not sure that it's working, but more hack'ier and fun: open YourProject.csproj file in text editor, replace <ProjectTypeGuids ...> section by such ones, that could be found in csproj file of ASP.NET project.
Class library projects can not be run, you can debug them though. See Debugging DLL Projects
A project with an output type of class Library cannot be started directly.In order to debug this project, add an executable project to this solution which references the library project. Set the executable project as the startup project.Means
In VS.Net - right click on the page you want to be the initial startup page and set it to be the startup page.
I downloaded a C# project and I wish to debug the project to see how an algorithm implementation works.
The project has come in a Folder, inside this folder there are -
.sln file and
a folder which has source files and a .csproj file.
I installed Visual Studio and opened the .sln file present in the main folder. I built the project successfully, but when I try to debug the project I get this message:
A project with an Output type of Class Library cannot be started directly In order to debug this project, add an executable project to this solution which references the library project. Set the executable project as the startup project.
The strange part is that I don't see a main function anywhere.
What should I do to get round this hiccup?
The project you have downloaded compiles into a dll assembly and provide a set of classes with implemented functionality.
You should add to your solution a new project with Output Type of either Console Application or Windows Application (VS Add Project wizard will offer you different templates of Projects).
In the newly added project, you can implement logic to test your Class Library.
Output type of the project you can find and change by the following steps:
Right click on project in Solution Explorer -> Properties.
In opened tab with properties select Application and there will be ComboBox marked with Output Type label.
Just right click on the Project Solution
A window pops up.
Expand the common Properties.
Select Start Up Project
In there on right hand side Select radio button with Single Startup Project
Select your Project in there and apply.
That's it. Now save and build your project. Run the project to see the output.
This was the solution that worked for me since I couldn't find 'Common Properties' option.
Select your topmost level project in Solution Explorer.
Go to Project, and in contextual menu Set as StartUp Project.
See also: A project with an Output type of Class Library cannot be started directly
Just needs to go:
Solution Explorer-->Go to Properties --->change(Single Startup project) from.dll to .web
Then try to debug it.
Surely your problem will be solved.
The strange part is that I don't see a main function anywhere.
That is exactly your problem. The project merely creates a DLL. It has no executable to run.
You will need to add a second project, which is an executable which references the other project, and calls something in it.
1) Right Click on **Solution Explorer**
2) Go to the **Properties**
3) Expand **Common Properties**
4) Select **Start Up Project**
5) click the radio button (**Single Start_up Project**)
6) select your Project name
7) Then Debug Your project
Right Click on "Solution Explorer" -> "Properties"
Expand "Common Properties"
Select "Start Up Project"
click the radio button "Single Start_up Project"
select your Project name from the drop down list.
If still not working after the above steps, then try this.
Expand solutions explorer.
Right click on project name -> "Properties"
Go to "Application" tab
Select "Output type"
From the drop down list select the appropriate type according to your application.
"Windows application" or
"Console application"
Then save (ctrl + S)
Try debugging (F5)
You'll need some kind of app (Console Apps are my favorite for debugging, but a WinForm will do) which uses your Class Library. Just add a new project (in the same solution) of a Console Application or Windows Forms Application, and add a reference to your current project. Once you've done that, make any calls you need, set your break points, and go to town.
I had a similar issue when trying to use the Experimental Instance of Visual Studio 2013. This was for a vsix project (Creating Snippets).
Solution was:
Right Click Project in Solution Explorer > Properties > Debug
Setting the Start Action to "Start external program" and using the following path:
C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\devenv.exe
This option was set to "Start project" which won't work for the application output type Class Library, which caused that same error.
Note: Yours may differ depending on how you installed VS.
Error solutions is that you have already open your project but by mistake you have selected another class library .. that's reason this error is showing ... so what u need to do you u just select u r project then right click on u r project
after right click u can see the list box and select the "Set as start up project " option .
Accepted answer works if your solution has a project that compiles to an exe. If your solution does not have any projects that compile to an exe, then you have to use 'Start external program'.
VS2019 instructions:
right click -> properties on the main solution
debug, start external program, and add command line arguments
VS2022 instructions:
right click -> properties on the main solution
scroll down to Debug
Debug > General > Open debug launch profiles UI
left click the 'new' icon in the top left, select 'executable'
fill it out as per VS2019 (pick the exe and add command line arguments)
when clicking the start button, first select the profile you made
Suppose you have multiple project in the solution. Select the project that you want to view in browser and select 'Set as StartUp Project'. In your multiple project soln which was the main, the visual studio was unable to identify. this was the main problem.
You can right click the Class Library project and from the drop-down choose Initialize Interactive C# which will load your project context and you can work it in the interactive session.
In my case, the cause was that one of my projects in the solution wasn't loaded. The reason it couldn't load properly was that the file path length of one of the files was too long. Upon deleting this long file, I could reload the project, and build the solution.
If the question involves an Azure project, make sure you have the "Azure development" tool set installed, or when you go to run a solution you may get this same error.
Tools > Get Tools and Features... > Tick the box next to Azure development > Click install
None of the answers provided above helped me resolve this error, this is what resolved the issue for me.
Right click on the solution and select "Properties", which is in my case "Sintctech.Data".
Select the section called "Application".
Check what you have selected as your output type. If it is "Windows Application", change it to "Console Appication".
Rebuild and the problem should be fixed.