开发应用-职责链模式(Chain Of Resposibility Pattern)

/// <summary>
/// 职责链模式接口
/// </summary>
public interface IChain
{
   IChain Next { get; set; } //下一个职责链
   
   void HandleRequest(string request);
}

/// <summary>
/// 定义一个职责链基类
/// </summary>
public abstract class ChainBase : IChain
{
   protected ListBox _Log;
   protected IChain _NextChain;
   
   public virtual void HandleRequest(string request) { }
   public IChain Next { get { return _NextChain; } set { _NextChain = value; } }
}

/// <summary>
/// 刷员工卡上下班或报工
/// </summary>
public class ChainEmployeeCard : ChainBase
{
   public ChainEmployeeCard(ListBox log) { _Log = log; }
   
   public override void HandleRequest(string request)
   {
      string employees = ",E01,E02,E03,"; //模拟员工表的数据
      
      if (employees.IndexOf(request) > 0) //如果员工表存在该卡号,由当前职责链处理请求
      {
         //在这里处理请求....
         _Log.Items.Add(request.ToUpper() ":调用ChainEmployeeCard职责链进行处理!");
      }
      else if (_NextChain != null)
      {
         _NextChain.HandleRequest(request);
      }
   }
}

/// <summary>
/// 刷产品卡进行报工
/// </summary>
public class ChainProductCard : ChainBase
{
   public ChainProductCard(ListBox log) { _Log = log; }
   
   public override void HandleRequest(string request)
   {
      string productCards = ",P01,P02,P03,"; //模拟产品表的数据,每个产品编号对应一个ID卡号
      
      if (productCards.IndexOf(request) > 0)//如果产品表存在该卡号(ID),由当前职责链处理请求
      {
         //在这里处理请求....
         _Log.Items.Add(request.ToUpper() ":调用ChainProductCard职责链进行处理!");
      }
      else if (_NextChain != null)
      {
         _NextChain.HandleRequest(request);
      }
   }
}

/// <summary>
/// 刷批卡进行报工
/// </summary>
public class ChainBatchCard : ChainBase
{
   public ChainBatchCard(ListBox log) { _Log = log; }
   
   public override void HandleRequest(string request)
   {
      //模拟批卡表的数据,批卡是指一组产品的编号,每个批卡编号对应一个ID卡号
      string batchCards = ",B01,B02,B03,";
      
      if (batchCards.IndexOf(request) > 0)//如果批卡表存在该卡号(ID),由当前职责链处理请求
      {
         //在这里处理请求....
         _Log.Items.Add(request.ToUpper() ":调用ChainBatchCard职责链进行处理!");
      }
      else if (_NextChain != null)
      {
         _NextChain.HandleRequest(request);
      }
   }
}

/// <summary>
/// 处理无法识别的卡号,是职任链的终端
/// </summary>
public class ChainInvalidRequest : ChainBase
{
   public ChainInvalidRequest(ListBox log) { _Log = log; }
   
   public override void HandleRequest(string request)
   {
      //这个职责链是处理终端,再也不会调用下一个职责链处理请求了
      //
      _Log.Items.Add(request.ToUpper() ":调用ChainInvalidRequest职责链进行处理!");
      _Log.Items.Add("请求无法识别!");
   }
}

/// <summary>
/// 职责链生成器. 实际是一个标准的生成器模式
/// </summary>
public class ChainBuilder
{
   /// <summary>
   /// 生成一个职责链. (链头)A->B->C->D->E->F->...n->终端职责(链尾)
   /// </summary>
   public static IChain BuildChain(ListBox log)
   {
      //链头,分析是否管理卡号的优先级最高. 链头可以自由更改
      IChain header = new ChainCommandCard(log);//链头
      IChain chain = header;
      
      //建立职责链处理顺序. 如需求有变在这里调整职责链顺序
      chain = chain.Next = new ChainEmployeeCard(log);
      chain = chain.Next = new ChainBatchCard(log);
      chain = chain.Next = new ChainProductCard(log);
      chain = chain.Next = new ChainInvalidRequest(log);
      
      return header;//返回职责链实例
   }
}

// 来源:www.CSFramework.com, C/S结构框架学习网

public partial class frmMain : Form
{
   private IChain _MyChain = null;
   
   public frmMain()
   {
      InitializeComponent();
   }
   
   private void frmMain_Load(object sender, EventArgs e)
   {
      //调用生成器创建一个完整的职责链
      _MyChain = ChainBuilder.BuildChain(this.listBox1);
   }
   
   private void btnAnalysis_Click(object sender, EventArgs e)
   {
      if (txtCardNo.Text.Length < 3)
      {
         MessageBox.Show("卡号太短啦!");
         return;
      }
      
      if (txtCardNo.Text.Trim() != "")
      {
         _MyChain.HandleRequest(txtCardNo.Text.ToUpper().Trim()); //分析请求,匹配职责链....
         
         txtCardNo.Clear();
         txtCardNo.Focus();
      }
   }
   
   private void btnClear_Click(object sender, EventArgs e)
   {
      listBox1.Items.Clear();
   }
   
   private void frmMain_Activated(object sender, EventArgs e)
   {
      txtCardNo.Focus();
   }
}

// 来源:www.CSFramework.com, C/S结构框架学习网