工作流学习笔记-ifElse活动;从工作流中取出返回值;计算器实例

新建一个项目->顺序工作流库

设计面板拖放ifElse活动

点右键，添加三个分支

每个分支的条件设置为声明性规则条件

并设置他们的名称和表达式

代码如下：

?

using System;

using System.ComponentModel;

using System.ComponentModel.Design;

using System.Collections;

using System.Drawing;

using System.Linq;

using System.Workflow.ComponentModel.Compiler;

using System.Workflow.ComponentModel.Serialization;

using System.Workflow.ComponentModel;

using System.Workflow.ComponentModel.Design;

using System.Workflow.Runtime;

using System.Workflow.Activities;

using System.Workflow.Activities.Rules;

 

namespace WorkflowLibrary1

{

    public sealed partial class Workflow1: SequentialWorkflowActivity

    {

        public string Operation { get; set; }

        public int Number1 { get; set; }

        public int Number2 { get; set; }

        public double Result { get; set; }

 

        public Workflow1()

        {

            InitializeComponent();

        }

 

        private void codeActivity1_ExecuteCode(object sender, EventArgs e)

        {

            Result = Number1 + Number2;

        }

 

        private void codeActivity2_ExecuteCode(object sender, EventArgs e)

        {

            Result = Number1 - Number2;

        }

 

        private void codeActivity3_ExecuteCode(object sender, EventArgs e)

        {

            Result = Number1 * Number2;

        }

 

        private void codeActivity4_ExecuteCode(object sender, EventArgs e)

        {

            if (Number2 != 0)

            {

                Result = (double)Number1 / (double)Number2;

            }

            else

            {

                throw new ArgumentException("除数为0");

            }

        }

 

        private void codeActivity5_ExecuteCode(object sender, EventArgs e)

        {

            throw new ArgumentException("没有找到合适的运算符：{0}", this.Operation);

        }

    }

 

}

在解决方案中创建windows form项目

设计一个简单的计算器的界面

做代码如下

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using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Workflow.Runtime;

using System.Threading;

using WorkflowLibrary1;

 

namespace test

{

    public partial class Form1 : Form

    {

        private WorkflowRuntime _wfRuntime;

        private AutoResetEvent _waitHandle = new AutoResetEvent(false);//已发生事件

        private string _result;

        public Form1()

        {

            InitializeComponent();

            initWFRuntime();//一个appdomain只能初始化一次

        }

        /// <summary>

        /// 工作流初始化

        /// </summary>

        private void initWFRuntime()

        {

            _wfRuntime = new WorkflowRuntime();

            _wfRuntime.WorkflowCompleted += new EventHandler<WorkflowCompletedEventArgs>(_wfRuntime_WorkflowCompleted);

            _wfRuntime.WorkflowTerminated += new EventHandler<WorkflowTerminatedEventArgs>(_wfRuntime_WorkflowTerminated);

        }

 

        void _wfRuntime_WorkflowTerminated(object sender, WorkflowTerminatedEventArgs e)

        {

            MessageBox.Show(e.Exception.Message);

            _waitHandle.Set();//发生事件已终止

        }

 

        void _wfRuntime_WorkflowCompleted(object sender, WorkflowCompletedEventArgs e)

        {

            _result = e.OutputParameters["Result"].ToString();

            _waitHandle.Set();

        }

        private void getResult()

        {

            Dictionary<string, object> dic = new Dictionary<string, object>();

            dic.Add("Operation", textBox2.Text.Trim());

            dic.Add("Number2", int.Parse(textBox3.Text.Trim()));

            dic.Add("Number1", int.Parse(textBox1.Text.Trim()));

            WorkflowInstance wfInstance = _wfRuntime.CreateWorkflow(typeof(WorkflowLibrary1.Workflow1), dic);

            wfInstance.Start();

            _waitHandle.WaitOne();

        }

        /// <summary>

        /// 注册按钮事件

        /// </summary>

        /// <param name="sender"></param>

        /// <param name="e"></param>

        private void Form1_Load(object sender, EventArgs e)

        {

            foreach (var ctl in this.Controls)

            {

                if (ctl is Button)

                {

                    ((Button)ctl).Click += new EventHandler(Form1_Click);

                }

            }

        }

        /// <summary>

        /// 按钮事件

        /// </summary>

        /// <param name="sender"></param>

        /// <param name="e"></param>

        void Form1_Click(object sender, EventArgs e)

        {

            Button btn = (Button)sender;

            TextBox tb;

            if (string.IsNullOrEmpty(textBox1.Text.Trim()))

            {

                tb = textBox1;

            }

            else if (string.IsNullOrEmpty(textBox3.Text.Trim()))

            {

                tb = textBox3;

            }

            else

            {

                tb = textBox1;

            }

            switch (btn.Text)

            {

                case "1":

                case "2":

                case "3":

                case "4":

                case "5":

                case "6":

                case "7":

                case "8":

                case "9":

                case "0":

                    tb.Text = btn.Text;

                    break;

                case "+":

                case "-":

                case "*":

                case "/":

                    textBox2.Text = btn.Text;

                    break;

                case "=":

                    getResult();

                    textBox4.Text = _result;

                    break;

                default:

                    break;

            }

        }

    }

}