最近不少朋友对我以前发的一些例子中的流程设计器有一些疑问，以后我会专门写一个流程设计器的例子,这里先写几个开发流程设计器时要用到的小知识点
1.为自定义的Activity添加图标
为自定义Activity设置成员属性
[System.Drawing.ToolboxBitmap(typeof(wxdActivity), "wxd.bmp")]public class wxdActivity : System.Workflow.ComponentModel.Activity2.为Activity设置外观
//设计器样式类 [ActivityDesignerThemeAttribute(typeof(wxdTheme))] public class wxdActivityDesigner : ActivityDesigner
{
} //主题类 public class wxdTheme : ActivityDesignerTheme {
public wxdTheme(WorkflowTheme theme) : base(theme)
{
this.BorderColor = Color.Red; //边框色 this.BorderStyle = DashStyle.Dash ; //边框线条 this.BackColorStart = Color.White; //渐变开始色 this.BackColorEnd = Color.Blue; //渐变结束色 this.BackgroundStyle = LinearGradientMode.ForwardDiagonal;//渐变方向 
} }为自定义Activity设置成员属性
[Designer(typeof(wxdActivityDesigner), typeof(IDesigner))]public class wxdActivity : System.Workflow.ComponentModel.Activity
如果在继承了SequenceActivity的Activity使用了上面方式定义的主题，可以使用其内部Activity结构不显示,有时不想在流程设计器中对用户暴露太多信息可以用这个方法
3.为Activity添加右键菜单与数据绑定窗体
有时使用属性栏对Activity进行设置，对用户来说不是很方便，比如有些属性值是用户名，设备名等要从数据库中动态加载的数据，这时为最好提供一个数据绑定窗体向导
using System.Workflow.ComponentModel;using System.ComponentModel;using System.Workflow.ComponentModel.Design;using System.Drawing;using System.Drawing.Drawing2D;using System.ComponentModel.Design;using System;using System.Collections.Generic;namespace wxwinter{ //自定义Activity [Designer(typeof(wxdActivityDesigner), typeof(IDesigner))] public class wxdActivity : System.Workflow.ComponentModel.Activity { public static DependencyProperty wxdValueProperty = DependencyProperty.Register("wxdValue", typeof(string), typeof(wxdActivity)); [Browsable(true)] [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)] public string wxdValue { get { return ((string)(base.GetValue(wxdActivity.wxdValueProperty))); } set { base.SetValue(wxdActivity.wxdValueProperty, value); } } } //自定义设计器 public class wxdActivityDesigner : ActivityDesigner { protected override System.Collections.ObjectModel.ReadOnlyCollection<DesignerAction> DesignerActions { get { List<DesignerAction> list = new List<DesignerAction>(); foreach (DesignerAction temp in base.DesignerActions) { list.Add(new DesignerAction(this, temp.ActionId, temp.Text)); } return list.AsReadOnly(); } } protected override ActivityDesignerVerbCollection Verbs { get { ActivityDesignerVerbCollection NewVerbs = new ActivityDesignerVerbCollection(); NewVerbs.AddRange(base.Verbs); ActivityDesignerVerb menu = new ActivityDesignerVerb(this, DesignerVerbGroup.View, "设置wxdValue", new EventHandler(menu_click)); NewVerbs.Add(menu); return NewVerbs; } } //当添加的菜单单击时要执行的操作 private void menu_click(object sender, EventArgs e) { using (wxdSetForm wf = new wxdSetForm()) { string v = (string)this.Activity.GetValue(wxdActivity.wxdValueProperty); wf.Value = v; wf.ShowDialog(); this.Activity.SetValue(wxdActivity.wxdValueProperty,wf.Value); } } } //自定义数据设置窗体 public class wxdSetForm : System.Windows.Forms.Form { public string Value; System.Windows.Forms.TextBox tx = new System.Windows.Forms.TextBox(); System.Windows.Forms.Button bt = new System.Windows.Forms.Button(); public wxdSetForm() { bt.Top=30; this.Controls.Add(tx); this.Controls.Add(bt); bt.Click += new EventHandler(bt_Click); bt.Text = "确定"; this.Load += new EventHandler(wxdSetForm_Load); } void wxdSetForm_Load(object sender, EventArgs e) { this.tx.Text = Value; } void bt_Click(object sender, EventArgs e) { this.Value = this.tx.Text; this.Hide(); } }}以上生成的Activity可以在VS中使用，也可以在我以前的流程设计器例子中使用
4.为Activity添加属性验证器
using System.Workflow.ComponentModel;using System.ComponentModel;using System.Workflow.ComponentModel.Design;using System.Drawing;using System.Drawing.Drawing2D;using System.ComponentModel.Design;using System;using System.Collections.Generic;using System.Workflow.ComponentModel.Compiler;namespace wxwinter{ //自定义Activity [ActivityValidator(typeof(wxdActivityValidator))] public class wxdActivity : System.Workflow.ComponentModel.Activity { public static DependencyProperty wxdValueProperty = DependencyProperty.Register("wxdValue", typeof(string), typeof(wxdActivity)); [Browsable(true)] [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)] public string wxdValue { get { return ((string)(base.GetValue(wxdActivity.wxdValueProperty))); } set { base.SetValue(wxdActivity.wxdValueProperty, value); } } } //验证器类 public class wxdActivityValidator : System.Workflow.ComponentModel.Compiler.ActivityValidator { public override ValidationErrorCollection ValidateProperties(ValidationManager manager, object obj) { ValidationErrorCollection Errors = base.ValidateProperties(manager, obj); if (obj != null) { this.wxdValueValidator(Errors, (wxdActivity)obj); } return Errors; } private void wxdValueValidator(ValidationErrorCollection Errors, wxdActivity obj) { if (obj.wxdValue=="") { Errors.Add(ValidationError.GetNotSetValidationError(wxdActivity.wxdValueProperty.Name)); } } }}
5.运行时动态将字符串编译为C#可执行代码
(与WF无关，这是C#的基础知识，在作流程设计器时有时会用到)
private void button1_Click(object sender, EventArgs e) { CSharpCodeProvider CSharp = new CSharpCodeProvider(); String[] dll = { "System.dll", "System.Windows.Forms.dll"