Passing Lambda expression to Workflow Code Activity as a parameter

Question

I am wondering if Lambda expression could be passed to Windows workflow Code Activity as a parameter?

I am trying to query ldap for user objects based on a lambda expression which would be passed to a Windows workflow Code Activity as a parameter.

Answer 1

A lamda expression is just a reference, pass it as you would any other data.

class Program
{
    static void Main(string[] args)
    {
        var workflow = new ExecuteFunc<int>();
        var inputs = new Dictionary<string, object>();
        inputs["Func"] = new Func<int, int>(maxValue =>
        {
            var rnd = new Random(Environment.TickCount);
            return rnd.Next(maxValue);
        });
        inputs["MaxValue"] = 100;
        WorkflowInvoker.Invoke(workflow, inputs);
    }
}

public class ExecuteFunc<T> : CodeActivity<T>
{
    public InArgument<int> MaxValue { get; set; }
    public InArgument<Func<int, T>> Func { get; set; }

    protected override T Execute(CodeActivityContext context)
    {
        var func = Func.Get(context);
        var maxValue = MaxValue.Get(context);
        var result = func(maxValue);
        Console.WriteLine(result);
        return result;
    }
}