Building 2 programs in a C# project

问题

Short Version

In a C# project created by dotnet new console, all of the *.cs files, even the ones in subdirectories, are compiled into a single program. If there are 2 classes with Main functions, it fails to build. How do I tell it to build 2 programs?

More Details

As a newcomer to C# and all of the related tools, I followed the tutorials, and learned how to create a minimal project by running dotnet new console, throw in some *.cs files, and run the resulting program with dotnet run. I even made a usable "release" with dotnet publish. All of this is coordinated by this *.csproj file:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.2</TargetFramework>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Newtonsoft.Json" Version="12.0.2"/>
  </ItemGroup>
</Project>

If A.cs and B.cs both declare Main, the build fails with error CS0017: Program has more than one entry point defined. Compile with /main to specify the type that contains the entry point.. So I have a clue that there is a /main option, but I don't know where to put it. dotnet run /main A.cs is not it.

The goal is to have something that looks like dotnet run /main A.cs but actually works; and to have dotnet publish create both A.exe and B.exe (or the closest equivalent for the target platform).

I expect that I will have to do some non-trivial *.csproj editing, but all I know about that file is that dotnet new created it, and dotnet add package put in the PackageReference. The actual build rules are hidden away in the Sdk and I don't know how to control what it does.

Related question

This question looks the same as mine, but the accepted answer only builds one of the programs.

回答1:

You have to have two separate projects to produce two separate EXEs. Shared code will usually go in a third "Library" project that both depend on. Though you can make one application project depend on the other, but this would be a bit odd.

回答2:

I think you want to reference another project. you can use dotnet add reference command or this command dotnet add [<PROJECT>] reference [-f|--framework] <PROJECT_REFERENCES> just replace PROJECT with your project name and PROJECT_REFERENCES with the project you want to reference or you can directly type project references.

    <ItemGroup>
      <ProjectReference Include="app.csproj" />
      <ProjectReference Include="..\lib2\lib2.csproj" />
      <ProjectReference Include="..\lib1\lib1.csproj" />
    </ItemGroup>

in project file.

This will build you all project with the refrenced project also.

来源：https://stackoverflow.com/questions/56914352/building-2-programs-in-a-c-sharp-project

标签

.net-core

csproj