Hosting Windows Forms Designer - Serialize designer at runtime and generate C# code

Assuming you have a DesignSurface to show a Form as root component of the designer and having some components created at run-time by using CreateComponent method of IDesignerHost, here is how I approach the problem:

• Get an instance of IDesignerHost from DesignSurface
• Create new DesignerSerializationManager
• Get an instance of TypeCodeDomSerializer from serialization manager
• Serialize the RootComponent of the IDesignerHost
• Create an instance of CSharpCodeProvider
• Generate code by calling GenerateCodeFromType and passing the serialized root component.

You can also extend the example a bit and use ISelectionService to get notified about selected components and change properties at run-time using a PropertyGrid:

Example - Generate C# code from DesignSurface at runtime

Here in this example, I'll show how you can host a windows forms designer at run-time and design a form containing some controls and components and generate C# code at run-time and run the generated code.

Please note: It's not a production code and it's just an example as a proof of concept.

Create the DesignSurface and host the designer

You can create the design surface like this:

DesignSurface designSurface;
private void Form1_Load(object sender, EventArgs e)
{
    designSurface = new DesignSurface(typeof(Form));
    var host = (IDesignerHost)designSurface.GetService(typeof(IDesignerHost));
    var root = (Form)host.RootComponent;
    TypeDescriptor.GetProperties(root)["Name"].SetValue(root, "Form1");
    root.Text = "Form1";

    var button1 = (Button)host.CreateComponent(typeof(Button), "button1");
    button1.Text = "button1";
    button1.Location = new Point(8, 8);
    root.Controls.Add(button1);

    var timer1 = (Timer)host.CreateComponent(typeof(Timer), "timer1");
    timer1.Interval = 2000;
    var view = (Control)designSurface.View;
    view.Dock = DockStyle.Fill;
    view.BackColor = Color.White;
    this.Controls.Add(view);
}

Generate C# code using TypeCodeDomSerializer and CSharpCodeProvider

This is how I generate code from design surface:

string GenerateCSFromDesigner(DesignSurface designSurface)
{
    CodeTypeDeclaration type;
    var host = (IDesignerHost)designSurface.GetService(typeof(IDesignerHost));
    var root = host.RootComponent;
    var manager = new DesignerSerializationManager(host);
    using (manager.CreateSession())
    {
        var serializer = (TypeCodeDomSerializer)manager.GetSerializer(root.GetType(),
            typeof(TypeCodeDomSerializer));
        type = serializer.Serialize(manager, root, host.Container.Components);
        type.IsPartial = true;
        type.Members.OfType<CodeConstructor>()
            .FirstOrDefault().Attributes = MemberAttributes.Public;
    }
    var builder = new StringBuilder();
    CodeGeneratorOptions option = new CodeGeneratorOptions();
    option.BracingStyle = "C";
    option.BlankLinesBetweenMembers = false;
    using (var writer = new StringWriter(builder, CultureInfo.InvariantCulture))
    {
        using (var codeDomProvider = new CSharpCodeProvider())
        {
            codeDomProvider.GenerateCodeFromType(type, writer, option);
        }
        return builder.ToString();
    }
}

For example:

var code = GenerateCSFromDesigner(designSurface);

Run the code sing CSharpCodeProvider

Then to run it:

void Run(string code, string formName)
{
    var csc = new CSharpCodeProvider();
    var parameters = new CompilerParameters(new[] {
    "mscorlib.dll",
    "System.Windows.Forms.dll",
    "System.dll",
    "System.Drawing.dll",
    "System.Core.dll",
    "Microsoft.CSharp.dll"});
    parameters.GenerateExecutable = true;
    code = $@"
        {code}
        public class Program
        {{
            [System.STAThread]
            static void Main()
            {{
                System.Windows.Forms.Application.EnableVisualStyles();
                System.Windows.Forms.Application.SetCompatibleTextRenderingDefault(false);
                System.Windows.Forms.Application.Run(new {formName}());
            }}
        }}";
    var results = csc.CompileAssemblyFromSource(parameters, code);
    if (!results.Errors.HasErrors)
    {
        System.Diagnostics.Process.Start(results.CompiledAssembly.CodeBase);
    }
    else
    {
        var errors = string.Join(Environment.NewLine,
            results.Errors.Cast<CompilerError>().Select(x => x.ErrorText));
        MessageBox.Show(errors);
    }
}

For example:

Run(GenerateCSFromDesigner(designSurface), "Form1");