System.CodeDom 9.0.21

About

Provides functionality for dynamically generating and compiling source code using the Code Document Object Model (CodeDOM).

It allows developers to represent code in a language-agnostic format and then generate code in multiple languages, such as C# and VB.NET. The primary use cases include creating dynamic code generation tools, runtime code generation, and facilitating code analysis or transformation.

For a new modern development consider using the .NET Compiler Platform SDK, in particular Roslyn source generators.

Key Features

• Write code using a common object model that can be translated into multiple programming languages.
• Generate and compile code at runtime based on the CodeDOM.

How to Use

Generating and compiling C# code:

using System.CodeDom;
using System.CodeDom.Compiler;
using Microsoft.CSharp;

// Create a new CodeCompileUnit to hold the code
var compileUnit = new CodeCompileUnit();

// Create a namespace
var codeNamespace = new CodeNamespace("MyNamespace");
compileUnit.Namespaces.Add(codeNamespace);

// Create a class
var classDeclaration = new CodeTypeDeclaration("MyClass")
{
    IsClass = true
};
codeNamespace.Types.Add(classDeclaration);

// Add a simple method to the class
var method = new CodeMemberMethod
{
    Name = "HelloWorld",
    ReturnType = new CodeTypeReference(typeof(void)),
};
classDeclaration.Members.Add(method);

var methodInvocation = new CodeMethodInvokeExpression(new CodeTypeReferenceExpression("Console"),
                                                      "WriteLine",
                                                      new CodePrimitiveExpression("Hello, World!"));
method.Statements.Add(methodInvocation);

// Generate C# code from the CodeDOM structure
CodeDomProvider provider = new CSharpCodeProvider();

using (var writer = new StringWriter())
{
    var codeGenereationOptions = new CodeGeneratorOptions()
    {
        BlankLinesBetweenMembers = false,
        IndentString = "  ",
    };

    provider.GenerateCodeFromCompileUnit(compileUnit, writer, codeGenereationOptions);
    Console.WriteLine(writer.GetStringBuilder().ToString());
}

This example generates:

//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

namespace MyNamespace {

  public class MyClass {
    private void HelloWorld() {
      Console.WriteLine("Hello, World!");
    }
  }
}

Main Types

The main types provided by this library are:

• System.CodeDom.CodeObject
• System.CodeDom.CodeCompileUnit
• System.CodeDom.CodeNamespace
• System.CodeDom.CodeTypeDeclaration
• System.CodeDom.CodeMemberMethod
• System.CodeDom.CodeTypeReference
• System.CodeDom.CodeMethodInvokeExpression
• System.CodeDom.CodeTypeReferenceExpression
• System.CodeDom.CodePrimitiveExpression
• System.CodeDom.Compiler.CodeDomProvider
• System.CodeDom.Compiler.CodeGeneratorOptions
• Microsoft.CSharp.CSharpCodeProvider
• Microsoft.VisualBasic.VBCodeProvider

Additional Documentation

• API documentation
• Compile and generate dynamic source code

Feedback & Contributing

System.CodeDom is released as open source under the MIT license. Bug reports and contributions are welcome at the GitHub repository.