在设计时在复合 WF4 活动中设置内部属性 [英] Setting internal properties in composite WF4 Activities at design time

问题描述

我想创建一个复合 Windows 工作流活动(在 .NET 4 下)，其中包含一个预定义的 ReceiveAndSendReply 活动.一些属性是预定义的，但其他属性(特别是 ServiceContractName)需要在设计器中设置.

I want to create a composite Windows Workflow Activity (under .NET 4) that contains a predefined ReceiveAndSendReply Activity. Some of the properties are predefined, but others (particularly ServiceContractName) need to be set in the designer.

我可以将其实现为活动模板(与实现 ReceiveAndSendReply 的方式相同)，但我宁愿不这样做.如果我稍后更改模板，则必须手动更新所有以前创建的工作流程.模板还允许其他开发人员更改应该修复的属性.

I could implement this as an Activity Template (the same way ReceiveAndSendReply is implemented), but would rather not. If I later change the template, I'd have to update all previously created workflows manually. A template would also permit other developers to change properties that should be fixed.

有没有办法从 Xaml 活动中做到这一点?我还没有找到将 Argument 值分配给嵌入活动的属性的方法.如果没有，你会建议什么技术?

Is there a way to do this from a Xaml Activity? I have not found a way to assign an Argument value to a property of an embedded Activity. If not, what technique would you suggest?

推荐答案

我没有使用复合 XAML 活动完成此操作，并且在尝试时遇到一些错误，但通过 NativeActivity 执行此操作没有问题.请参阅下面的示例代码.

I haven't done this using a composite XAML activity and am getting some errors when I try but doing so through a NativeActivity is no problem. See the example code below.

public class MyReceiveAndSendReply : NativeActivity
{
    private Receive _receive;
    private SendReply _sendReply;

    public string ServiceContractName { get; set; }
    public string OperationName { get; set; }

    protected override bool CanInduceIdle
    {
        get { return true; }
    }

    protected override void CacheMetadata(NativeActivityMetadata metadata)
    {
        _receive = _receive ?? new Receive();
        _sendReply = _sendReply ?? new SendReply();
        _receive.CanCreateInstance = true;
        metadata.AddImplementationChild(_receive);
        metadata.AddImplementationChild(_sendReply);

        _receive.ServiceContractName = ServiceContractName;
        _receive.OperationName = OperationName;

        var args = new ReceiveParametersContent();
        args.Parameters["firstName"] = new OutArgument<string>();
        _receive.Content = args;

        _sendReply.Request = _receive;

        var results = new SendParametersContent();
        results.Parameters["greeting"] = new InArgument<string>("Hello there");
        _sendReply.Content = results;

        base.CacheMetadata(metadata);
    }

    protected override void Execute(NativeActivityContext context)
    {
        context.ScheduleActivity(_receive, ReceiveCompleted);

    }

    private void ReceiveCompleted(NativeActivityContext context, ActivityInstance completedInstance)
    {
        context.ScheduleActivity(_sendReply);
    }
}

这篇关于在设计时在复合 WF4 活动中设置内部属性的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！