SharePoint designer出错，缺少自定义活动所需的参数

我正在为SharePoint 2010制作自定义活动。当我在SharePoint Designer中删除该活动并提供参数值时，会出现一个神秘的验证错误，它简单地说：

此操作缺少必需的参数

以下是操作的源代码：

using System;
using System.ComponentModel;
using System.Diagnostics;
using System.IO;
using System.Workflow.ComponentModel;
using System.Workflow.Activities;
using System.Workflow.ComponentModel.Compiler;
using Microsoft.SharePoint;
using Microsoft.SharePoint.WorkflowActions;

namespace SharePoint.Activities.IO
{
    public partial class CopyFile : SequenceActivity
    {
        public CopyFile()
        {
            InitializeComponent();
        }

        public static DependencyProperty SourceDirectoryProperty = DependencyProperty.Register("SourceDirectory", typeof(string), typeof(CopyFile));
        public static DependencyProperty TargetDirectoryProperty = DependencyProperty.Register("TargetDirectory", typeof(string), typeof(CopyFile));
        public static DependencyProperty ActionResultProperty = DependencyProperty.Register("ActionResult", typeof(string), typeof(CopyFile));
        public static DependencyProperty CreateDateProperty = DependencyProperty.Register("CreateDate", typeof(DateTime), typeof(CopyFile));
        public static DependencyProperty CompletionDateProperty = DependencyProperty.Register("CompletionDate", typeof(DateTime), typeof(CopyFile));
        public static DependencyProperty WFContextProperty = DependencyProperty.Register("WFContext", typeof(WorkflowContext), typeof(CopyFile));

        [Description("Path the files to perform the operation on")]
        [Browsable(true)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        [ValidationOption(ValidationOption.Required)]
        public string SourceDirectory
        {
            get { return (string)GetValue(SourceDirectoryProperty); }
            set { SetValue(SourceDirectoryProperty, value); }
        }
        [Description("Path the files are copied to")]
        [Browsable(true)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        [ValidationOption(ValidationOption.Required)]
        public string TargetDirectory
        {
            get { return (string)GetValue(TargetDirectoryProperty); }
            set { SetValue(TargetDirectoryProperty, value); }
        }
        [Description("Once the the operation completes, this is set to OK or the exception information")]
        [Browsable(true)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        [ValidationOption(ValidationOption.Optional)]
        public string ActionResult
        {
            get { return (string)GetValue(ActionResultProperty); }
            set { SetValue(ActionResultProperty, value); }
        }
        [Description("When the request was created")]
        [Browsable(true)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        [ValidationOption(ValidationOption.Optional)]
        public DateTime CreateDate
        {
            get { return (DateTime)GetValue(CreateDateProperty); }
            set { SetValue(CreateDateProperty, value); }
        }
        [Description("When execution stoped")]
        [Browsable(true)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        [ValidationOption(ValidationOption.Optional)]
        public DateTime CompletionDate
        {
            get { return (DateTime)GetValue(CompletionDateProperty); }
            set { SetValue(CompletionDateProperty, value); }
        }

        [Browsable(true)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        public WorkflowContext WFContext
        {
            get { return (WorkflowContext)GetValue(WFContextProperty); }
            set { SetValue(WFContextProperty, value); }
        }

        //protected override void Initialize(IServiceProvider provider)
        //{
        //    TraceIn();
        //    base.Initialize(provider);
        //    TraceOut();
        //}

        protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext)
        {
            TraceIn();

            Debugger.Break();

            var isSiteAdmin = false;
            CreateDate = DateTime.Now;
            try
            {
                // Needs administrative credentials to get the web application properties ino
                SPSecurity.RunWithElevatedPrivileges(delegate
                {
                    using (var site = new SPSite(WFContext.Site.ID))
                    {
                        using (var web = site.AllWebs[WFContext.Web.ID])
                        {
                            isSiteAdmin = web.CurrentUser.IsSiteAdmin;
                            if (string.IsNullOrEmpty(SourceDirectory)) throw new ArgumentException("SourceDirectory cannot be null or empty");
                            if (!Directory.Exists(SourceDirectory)) throw new DirectoryNotFoundException("Could not find source directory: \"" + SourceDirectory + "\"");

                            if (string.IsNullOrEmpty(TargetDirectory)) throw new ArgumentException("TargetDirectory cannot be null or empty");
                            if (!Directory.Exists(TargetDirectory)) throw new DirectoryNotFoundException("Could not find target directory: \"" + TargetDirectory + "\"");
                            // Do something 
                            Debug.WriteLine(string.Format("Doing something amazing from {0} and moving it to {1}", SourceDirectory, TargetDirectory));
                        }
                    }
                });

                ActionResult = "OK";
            }
            catch (Exception ex)
            {
                ActionResult = isSiteAdmin ? ex.ToString() : ex.Message;
            }
            CompletionDate = DateTime.Now;

            var result = base.Execute(executionContext);

            TraceOut();

            return result;
        }

        private static void TraceIn()
        {
            Trace("Entering");
        }

        private static void TraceOut()
        {
            Trace("Exiting");
        }

        private static void Trace(string direction)
        {
            Debugger.Launch();
            var stackTrace = new StackTrace(2, false);
            var frame = stackTrace.GetFrame(0);
            Debug.WriteLine(direction + " " + frame.GetMethod().Name);
        }
    }
}

这是.action文件

<?xml version="1.0" encoding="utf-8" ?>
<WorkflowInfo>
    <Actions
        Sequential="then"
        Parallel="and">
        <Action
            Name="IO Activities"
            ClassName="SharePoint.Activities.IO.CopyFile"
            Assembly="SharePoint.Activities.IO, Version=1.0.0.0, Culture=neutral, PublicKeyToken=abfb622251cf6982"
            Category="Custom Actions"
            AppliesTo="all">
            <RuleDesigner
                Sentence="CopyFiles from %1 to %2">
                <FieldBind
                    Field="SourceDirectory"
                    DesignerType="String"
                    Id="1"/>
                <FieldBind
                    Field="TargetDirectory"
                    DesignerType="String"
                    Id="2"/>
            </RuleDesigner>
            <Parameters>
                <Parameter
                    Name="SourceDirectory"
                    Type="System.String, mscorlib"
                    Direction="In"
                    DesignerType="StringBuilder"
                    Description="Directory where the source files are to move" />
                <Parameter
                    Name="TargetDirectory"
                    Type="System.String, mscorlib"
                    Direction="In"
                    DesignerType="StringBuilder"
                    Description="Directory where the files will be placed" />
                <Parameter
                    Name="ActionResult"
                    Type="System.String, mscorlib"
                    Direction="Optional" 
                    DesignerType="Hide" />
                <Parameter
                    Name="CreateDate"
                    Type="System.DateTime, mscorlib"
                    Direction="Optional" 
                    DesignerType="Hide" />
                <Parameter
                    Name="CompletionDate"
                    Type="System.DateTime, mscorlib"
                    Direction="Optional" 
                    DesignerType="Hide" />

                <Parameter 
                    Name="WFContext" 
                    Type="Microsoft.SharePoint.WorkflowActions.WorkflowContext, Microsoft.SharePoint.WorkflowActions" 
                    DesignerType="Hide" />
            </Parameters>
        </Action>
    </Actions>
</WorkflowInfo>

使现代化
我甚至尝试通过注释掉.actions文件中的参数、类中的属性以及注释掉DependencyProperties来删除所有参数。我仍然会遇到同样的错误。
最终，看起来问题（在我拆除项目并重新开始之后）是一个不正确的设计器类型和一个丢失的

以下是旧代码：

<FieldBind Field="Result" DesignerType="TextArea" Text="Action result message; returns OK on success" Id="3" />



以下是正确的代码：

<FieldBind Field="Result" DesignerType="ParameterNames" Text="Action result message; returns OK on success" Id="3" />



一旦做出了改变，一切似乎都在运转