Sorry if this is trivial, I am new to Visual Studio, I have a single project in which contains multiple class files (.cs) files, how do I run each one individually. Whenever I go to debug, it selects only a single .cs file. Thanks.
Edit : Coming from a java background using netbeans, it is possible to have a package with several .java files in the package, provided each of the .java files have a main method they can be individually compiled and ran. Is something like this available in Visual Studio?
If you want to select which Main method gets run, you can select that in Project -> Properties under Startup Object. There are various requirements that need to be met (like being static) and you can only select one at a time.
If you want to call the main method on multiple static classes, you'll need to create a main one that calls the other ones. You could get complicated and use reflection to search your project for the classes, but it's much more work than just statically calling them.
As the OP came from a Java background, I think it worth answering this question in a slightly different way.
I understand the the OP has a few different C# classes with their corresponding static Main() methods (each one of these classes probably being a different way to bootstrap the app code) and wants to easily switch between them when launching the app in Visual Studio.
So, the short answer is: there is no easy way :(
Firstly, you can not launch a project through a static Main() method if its output type is a "Class Library". You need to change it to either "Console Application" or "Windows Application" to be able to launch it. This is completely different from the Java world where you can simply right-click on any class with a static main() method, then click "Run as...", "Java Application". In Java, there is no such concept of a library project/module, so it doesn't matter if the project that contains this class with static main() is a "library" or not.
Secondly, the easiest way I found is (very similar to Ray's answer):
Right-click on the project, then "Properties"
In "Application", make sure your output type is not "Class Library"
Change "Startup Object" to the class whose static Main() is the one you want to run
Right-click on your project, "Debug", "Start New Instance"
Unfortunately, I see no way to save in VS different launch configurations for the same project using different classes, so that you can easily switch between them. AFAICS the only way to achieve that is to create new projects inside the solution and configure them to launch the different main classes.
Normally, you cannot build a single CS file unless you add it to a separate project. Visual Studio automatically builds all CS files in a project.
If you only want to build a single file you can change this in the settings of the file:
Click the files you do not want to build, look at the properties window (F4).
Set build action to None to disable building that file.
You can add the static main(string[] args) method to the class you want to run or make and object of the same class in program.cs and call the methods you need in the main() of program.cs
Changing static to private in files i want to exclude works for me, i leave only 1 file with static and visual studio runs only that one
I am new to dot net world and facing same issue. To practice C# need to write several small small code in diff .cs files but again as per dot net only one Main() can be present.
So if you have 10 .cs file then make sure you update their 'main' method name with small case
static void main(string[] args){}
And the file you want to run should have Main() method with capital M
static void Main(string[] args){}
Also even if your .cs file are in some other folder, you need to run command from root folder only
dotnet run
Program.cs contains what to run when the project is run.
Application.Run(new Form1());
You can use that to select any class to be run.
If it's a console application, only the class with the entry point is run.
static void Main(string[] args)
{
}
Only that class will run first which contains the "static Main" method.
Add a Main() method to the class you want to execute first.
Revert me if you need more help.
Hope this helps.
Related
Everyone.
Please I am new to c# program. I want to ask is it is possible to combine 3 separate independent programs to one executable file.
To explain what I mean:
program_1 has its' own .sln
program_2 has its' own .sln
program_2 has its' own .sln
,and I want to has a single .sln to output a single program.exe
They are all console APP.
Any guide would be highly appreciated
You should have one solution and many projects in that solution.One of the project have program.cs that class is start point of the entire solution.Usually you will see program.cs in the Console.app or WebApi etc or WinForm. When you right click on solution instead of creating ConsoleApp create ClassLibrary Project. But even your projects have different program.cs files you can use their classess in your other projects.
My MS Visual C# program was compiling and running just fine.
I close MS Visual C# to go off and do other things in life.
I reopen it and (before doing anything else) go to "Publish" my program and get the following error message:
Program C:\myprogram.exe does not contain a static 'Main' method suitable for an entry point
Huh? Yes it does... and it was all working 15 min earlier. Sure, I can believe that I accidentally hit something or done something before I closed it up... but what? How do I troubleshoot this?
My Program.cs file looks like this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using System.Threading;
namespace SimpleAIMLEditor
{
static class Program
{
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new mainSAEForm());
}
}
}
...and there are some comments in there. There are no other errors.
Help?
Are the properties on the file set to Compile?
I was struggle with this error just because one of my class library projects was set acceddentaly to be an console application
so make sure your class library projects is class library in Output type
Oke, I was looking at this issue as well. And in my case the solutions was too easy.
I added a new empty project to the solution. The newly added project is automatically set as a console application. But since the project added was a 'empty' project, no Program.cs existed in that new project. (As expected)
All I needed to do was change the output type of the project properties to Class library
If you have a WPF or Silverlight application, make sure that App.xaml has "ApplicationDefinition" as the BuildAction on the File Properties.
I had this error and solved by this solution.
--> Right click on the project
--> and select "Properties"
--> then set "Output Type" to "Class Library".
Check your project's properties. On the "Application" tab, select your Program class as the Startup object:
That's odd. Does your program compile and run successfully and only fail on 'Publish' or does it fail on every compile now?
Also, have you perhaps changed the file's properties' Build Action to something other than Compile?
I had this problem and its because I wasnt using the latest version of C# (C# 7.3 as of writing this) and I had to change the below internal access modifier to public.
internal class Program
{
public static void Main(string[] args)
{
//My Code
}
}
or ammend the .csproj to use the latest version of C# (this way meant I could still keep the above class as internal):
<PropertyGroup>
<LangVersion>latest</LangVersion>
<NoWin32Manifest>true</NoWin32Manifest>
</PropertyGroup>
I had changed
public static void Main(string[] args)
to
public async static void Main(string[] args)
The problem is that it needs to be a task:
public async static Task Main(string[] args)
For me same error occurred because I renamed the namespace of the Program class.
The "Startup object" field in "Application" tab of the project still referenced the old namespace. Selecting new startup object solved the problem and also removed the obsolete entry from that list.
You may also want to update "Default namespace" field in the same "Application" tab.
It is important that the Main method is placed in the class that is properly configured in Visual Studio as a start-up object:
Right-click your project in project explorer; choose "Properties..."
In the properties dialog, choose "Application" tab
In the application tab, choose SimpleAIMLEditor.Program from the drop-down for your start-up object
Now run your application again. The error will disappear.
What worked for me: Close MS Visual Studio, then start Visual Studio and open the solution. The error message was then gone.
What I found is that the Program.cs file was not part of the solution.
I did an add existing item and added the file (Program.cs) back to the solution.
This corrected the error:
Error 1 Program '..... does not contain a static 'Main' method suitable for an entry point
My problem is that I accidentally set the arguments for Main
static void Main(object value)
thanks to my refactoring tool. Took couple mins to figure out but should help someone along the way.
In my case (where none of the proposed solutions fit), the problem was I used async/await where the signature for main method looked this way:
static async void Main(string[] args)
I simply removed async so the main method looked this way:
static void Main(string[] args)
I also removed all instances of await and used .Result for async calls, so my console application could compile happily.
In my case it was an XUnit test library showing this error. I had mistakenly deleted the Microsoft.NET.Test.Sdk package.
In my dotnet core 3.1 project I had created a new class/file instead of Program.cs that contained the Main method.
I had to update the Startup object to my new class name in Project Properties
I had a similar problem but what solved it for me was making sure my launch.json and .csproj file were pointing to the same framework.
In launch.json this
"program": "${workspaceFolder}/bin/Debug/net6.0-windows/myproject.dll"
Was not the same as this in .csproj
<TargetFramework>net6.0-windows</TargetFramework>
Is there any way to change my class library program into an .exe or a click once-application? It is Currently a dll.
I am able to create a click once app but it is not working after installation.
In the properties of the project -> application tag, change the Output type to console Application. Anyway, you need to create a static Main() method as a starting point.
static void Main(string[] args)
{
}
You can change the output type of your project in it's settings, then add a main entrypoint, as others have mentioned (Note, you want "Windows application", not "Console Application" here):
If you can't change the source for some reason, you can create a new very simple application (an .exe), and call public methods in your .dll from it:
namespace YourNamespace
{
internal class YourApp
{
private static void Main(string[] args)
{
// Call your function here.
}
}
}
To do this, you just need to include a reference to the existing .dll into this new application.
Rather than changing it to an EXE - create a new project (Winform App, WPF, Console App, whatever) and reference your DLL to use the classes from it.
If you convert your DLL to an EXE then you lose (or at least significantly hinder) the ability to use those classes in any other application.
Keep non-UI classes in a DLL and only put UI-layer classes and controls in the executable.
Within dotnet core, just add this to the csproj, ideally within the first PropertyGroup:
<OutputType>Exe</OutputType>
Just watch out if your target framework was netstandard, that of course will not work (!).
I'm from Java to C# these days, and using Visual C# 2010 express.
Sometimes I want to write and test some simple code, but I found it not as easy as in Eclipse: write a main method in any java file, and run it.
In VC#, when I add a Main method in a .cs file, it will notice me there are two Main entry in this project. I have to rename the other one before running, and have to rename it back later.
Is there an easy way to do this?
Visual Studio works better for large projects. If you just want to test some code then I'd either stick it in the main method of your application, or forget VS and run it through a code scratchpad.
The best C# code scratchpad out there is LINQPad
Of course, if you're testing a lot you may need to stub out any dependencies that the code has. It's difficult to say without knowing the scope of your code, or the type of project.
As #Alexander R says, LINQPad is a great tool. I use it extensively for small snippets, like testing answers I post to Stack Overflow.
If I have to be able to call other code in my current project I add a unit test project to my solution. When I want to test something, I write the code in a new test method and then use the Ctrl+R, Ctrl+T shortcut to run the currently selected test method.
The mono compiler includes a REPL utility (http://www.mono-project.com/CsharpRepl). Something similar is supposed to be included in a future version of C# / Visual Studio (see the latest CTP of the Roslyn project).
Another possibility is the 'test driven .Net' utility, but that doesn't work with Visual Studio express. It (a.o.) allows you to run any method directly from within visual studio.
LINQPad and Snippet Compiler are also viable options.
You can also simply create a .cs file and compile it on the command line. For example, put this code in a file called hello.cs
using System;
public class Program {
public static void Main() {
Console.WriteLine("Hello World");
}
}
Then on the command line, compile with csc hello.cs
=> this creates hello.exe which you can then run.
In VC#, when I add a Main method in a .cs file, it will notice me there are two Main entry in this project.
Then don't add another main method. The file Program.cs will contain a main method when you've created a Console or WinForms application. If you want to test something, for example a class you've written, simply instantiate that class in the existing main method.
As solution why not adding
public testXXXX() method to every class you want to test and then have 1 main method in which you would call those testXXXX() methods.
What do I do if I just want to create a project which contains a bunch of library functions? In other words no Main method is required. It seemed to be compiling a minute ago and then I added another .cs file and now I am confronted with this error message.
Create a .NET Class Library project if you only want a library project. If this is a project that already exists, you can set the Project Output type to a DLL ("Class Library") instead of an Executable ("Windows Application"/"Console Application") in the project properties.
What type of project did you create? It sounds like you meant to create a class library but accidentally created an executable assembly. Ensure that you are in fact creating a class library assembly (i.e. ".dll" not ".exe").
If you aren't using Visual Studio and are compiling your code with csc.exe then make sure that you are specifying /target:library to compile your code into a library.
You want to make the project a Class Library type. I believe you can change the type of project in the project properties settings.
or you could use the tried-and-true empty main method
I have the solution. Really simple. You wrote the static void main with lower case. You should write it like this: static void Main()
This problem is occured when we deleted App.xaml file from our project after the required method written due to that please ensure that your App.xaml file is in correct format with respective namespace and references, if it is not, create it and add it in your project.