Programmatically create a csproj on the fly without Visual Studio installed

c#, csproj

Solution

If you really want to create a proj file with MSBuild API you have to use the Microsoft.Build.Construction namespace. Most of the types you will need are in the Micrsoft.Build.dll assembly. A short sample that creates a project file with a few properties and item groups:

class Program
{
    static void Main(string[] args)
    {
        var root = ProjectRootElement.Create();
        var group = root.AddPropertyGroup();
        group.AddProperty("Configuration", "Debug");
        group.AddProperty("Platform", "x64");

        // references
        AddItems(root, "Reference", "System", "System.Core");

        // items to compile
        AddItems(root, "Compile", "test.cs");

        var target = root.AddTarget("Build");
        var task = target.AddTask("Csc");
        task.SetParameter("Sources", "@(Compile)");
        task.SetParameter("OutputAssembly", "test.dll");

        root.Save("test.csproj");
        Console.WriteLine(File.ReadAllText("test.csproj"));
    }

    private static void AddItems(ProjectRootElement elem, string groupName, params string[] items)
    {
        var group = elem.AddItemGroup();
        foreach(var item in items)
        {
            group.AddItem(groupName, item);
        }
    }
}

Note that this just creates the proj file. It doesn't run it. Also, properties like "Configuration" and "Platform" are only meaningful in the context of a proj file generated by Visual Studio. Here they won't really do anything unless you add more property groups with conditions the way Visual Studio does automatically.

Like I indicated in my comments, I think this is wrong way to go about this. You really just want dynamic compilation of sources, which is available through CodeDom:

using System.CodeDom.Compiler;

class Program
{
    static void Main(string[] args)
    {
        var provider = CodeDomProvider.CreateProvider("C#");
        string[] sources = {
                               @"public abstract class BaseClass { public abstract void Test(); }",
                               @"public class CustomGenerated : BaseClass { public override void Test() { System.Console.WriteLine(""Hello World""); } }"
                           };

        var results = provider.CompileAssemblyFromSource(new CompilerParameters() {
            GenerateExecutable = false,
            ReferencedAssemblies = { "System.dll", "System.Core.dll" },
            IncludeDebugInformation = true,
            CompilerOptions = "/platform:anycpu"
        }, sources);
        if (results.Errors.Count > 0)
        {
            Console.WriteLine("{0} errors", results.Errors.Count);
            foreach(CompilerError error in results.Errors)
            {
                Console.WriteLine("{0}: {1}", error.ErrorNumber, error.ErrorText);
            }
        }
        else
        {
            var type = results.CompiledAssembly.GetType("CustomGenerated");
            object instance = Activator.CreateInstance(type);
            type.GetMethod("Test").Invoke(instance, null);
        }
    }
}

Problem

Original source