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

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;
}
}
}
}