Activity Customization Settings for Child Activity

Question

I am trying to create a custom action for WF4 that hosts a child activity, and pass some arguments to its child activity. Below I attach a simplified version of my actions ("Parent and Child")

public class Child : CodeActivity
{
    public InArgument<Dictionary<string, object>> Data;

    protected override void Execute(CodeActivityContext context)
    {
        Dictionary<string, object> data = Data.Get(context);

        //Some operations on the input data
    }
}


 public class Parent : NativeActivity
{
    public InArgument<int> Value1 { get; set; }

    public InArgument<string> Value2 { get; set; }

    public Child Body { get; set; }


    protected override void Execute(NativeActivityContext context)
    {
        int value1 = Value1.Get(context);
        string value2 = Value2.Get(context);

        Dictionary<string, object> data = new Dictionary<string, object>();
        data.Add("value1", value1);
        data.Add("value2", value2);

        context.SetValue(Body.Data, data);

        context.ScheduleActivity(this.Body);
    }


    protected override void CacheMetadata(NativeActivityMetadata metadata)
    {
        Body = new Child();

        base.CacheMetadata(metadata);
    }
}

The Data argument from the child action is null when the execution of the workflow reaches the Execute method for activity.

Can someone please give me some direction how arguments can be passed between these two actions?

Answer 1

, "" ActivityAcytion ActivityFunc.

, , .

public class Child : CodeActivity<object>
{
    public InArgument<Dictionary<string, object>> Data { get; set; }

    protected override object Execute(CodeActivityContext context)
    {
        Dictionary<string, object> data = Data.Get(context);

        foreach (var item in data)
        {
            Console.WriteLine(item);
        }

        return "Some result";
    }
}



public class Parent : NativeActivity<object>
{
    public InArgument<int> Value1 { get; set; }
    public InArgument<string> Value2 { get; set; }

    public ActivityFunc<Dictionary<string, object>, object> Body { get; set; }

    protected override void Execute(NativeActivityContext context)
    {
        int value1 = Value1.Get(context);
        string value2 = Value2.Get(context);

        Dictionary<string, object> data = new Dictionary<string, object>();
        data.Add("value1", value1);
        data.Add("value2", value2);

        context.ScheduleFunc<Dictionary<string, object>, object>(Body, data, ChildCompletionCallback);
    }


    protected override void CacheMetadata(NativeActivityMetadata metadata)
    {
        var arg = new DelegateInArgument<Dictionary<string, object>>();

        Body = new ActivityFunc<Dictionary<string, object>, object>
        {
            Argument = arg,
            Handler = new Child() { Data = arg }
        };

        base.CacheMetadata(metadata);
    }

    private void ChildCompletionCallback(NativeActivityContext context, ActivityInstance completedInstance, object result)
    {
        //Set the output for the parent activity at the completion of the child activity
        this.Result.Set(context, result);
    }
}

Answer 2

. ScheduleActivity CompletionCallback. /, out, , - - :)

:

public class Parent : NativeActivity<object>
{
    public InArgument<int> Value1 { get; set; }
    public InArgument<string> Value2 { get; set; }
    private Variable<Dictionary<string, object>> SomeVariable { get; set; } // intermediate variable

    private Child Body { get; set; }

    public Parent()
    {
        this.SomeVariable = new Variable<Dictionary<string, object>>("SomeVariable");

        this.Body = new Child();
        this.Body.Data = new InArgument<Dictionary<string, object>>(SomeVariable);
    }

    protected override void Execute(NativeActivityContext context)
    {
        int value1 = Value1.Get(context);
        string value2 = Value2.Get(context);

        Dictionary<string, object> data = new Dictionary<string, object>();
        data.Add("value1", value1);
        data.Add("value2", value2);

        this.SomeVariable.Set(context, data);

        context.ScheduleActivity(this.Body, ChildCompletionCallback);
    }

    protected override void CacheMetadata(NativeActivityMetadata metadata)
    {
        base.CacheMetadata(metadata);

        // needs to be cached as implementation child and variable (Body and SomeVariable must be declared as private then)
        metadata.AddImplementationChild(this.Body);
        metadata.AddImplementationVariable(SomeVariable);
    }

    private void ChildCompletionCallback<TResult>(NativeActivityContext context, ActivityInstance completedInstance, TResult result)
    {
        //Set the output for the parent activity at the completion of the child activity
        this.Result.Set(context, result);
    }
}

:

public class Child : CodeActivity<object>
{
    public InArgument<Dictionary<string, object>> Data { get; set; }

    protected override object Execute(CodeActivityContext context)
    {
        Dictionary<string, object> data = Data.Get(context);

        return "Some result";
    }
}

Answer 3

it may not be possible to set the value of the input argument directly in the Execute method. An intermediate variable must be entered. The Child.Data argument is also associated with this variable in the Parent.Execute method.

Parent:

public class Parent : NativeActivity
{
    public InArgument<int> Value1 { get; set; }
    public InArgument<string> Value2 { get; set; }
    private Variable<Dictionary<string, object>> SomeVariable { get; set; } // intermediate variable

    private Child Body { get; set; }

    public Parent()
    {
        this.SomeVariable = new Variable<Dictionary<string, object>>("SomeVariable");

        this.Body = new Child();
        this.Body.Data = new InArgument<Dictionary<string, object>>(SomeVariable);
    }

    protected override void Execute(NativeActivityContext context)
    {
        int value1 = Value1.Get(context);
        string value2 = Value2.Get(context);

        Dictionary<string, object> data = new Dictionary<string, object>();
        data.Add("value1", value1);
        data.Add("value2", value2);

        this.SomeVariable.Set(context, data);

        context.ScheduleActivity(this.Body);
    }

    protected override void CacheMetadata(NativeActivityMetadata metadata)
    {
        base.CacheMetadata(metadata);

        // needs to be cached as implementation child and variable (Body and SomeVariable must be declared as private then)
        metadata.AddImplementationChild(this.Body);
        metadata.AddImplementationVariable(SomeVariable);
    }
}

Child:

public class Child : CodeActivity
{
    // Must be declared as property.
    public InArgument<Dictionary<string, object>> Data
    {
        get;
        set;
    }

    protected override void Execute(CodeActivityContext context)
    {
        var data = this.Data.Get(context);
    }
}

This is not a good solution, but I see almost nothing in WF4 :).