子活动的自定义活动设置参数

Question

我正在尝试为承载子活动的WF4创建一个自定义活动,并将一些参数传递给它的子活动.我在下面附上我的活动的简化版本(父母和孩子)

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);
    }
}

当工作流程执行到达活动的Execute方法时,Child活动中的Data参数为null.

有人可以,请给我一些指示如何在这两个活动之间传递论据？

Answer 1

虽然使用额外变量的方法起作用,但使用ActivityAcytion或者如果您还想要一个带有ActivityFunc的结果,则使用某些输入调度子项的"官方"方式.

我担心代码不会变得更简单或更容易理解,但为了完整起见,我只是决定添加它.

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);
    }
}