设计模式12-命令模式

命令模式：将请求封装，用不同的请求对客户进行参数化，对请求排队或记录请求日志，及撤销操作。

 1 namespace DesignModel.命令模式
 2 {
 3     abstract class Command
 4     {
 5         protected Execer exe;
 6         public Command(Execer execer)
 7         {
 8             this.exe = execer;
 9         }
10         abstract public void ExecCommand();
11     }
12 
13     class CommandOne : Command
14     {
15         public CommandOne(Execer execer) : base(execer) { }
16         public override void ExecCommand()
17         {
18             exe.ExecCommandOne();
19         }
20     }
21     class CommandTwo : Command
22     {
23         public CommandTwo(Execer execer) : base(execer) { }
24         public override void ExecCommand() => exe.ExecCommandTwo();
25 
26     }
27 
28     class Execer
29     {
30         public void ExecCommandOne() => Console.WriteLine("");
31         public void ExecCommandTwo() => Console.WriteLine("");
32      }
33 
34 
35     class Builder
36     {
37         IList<Command> list = new List<Command>();
38         public Builder SetBuilder(Command command)
39         {
40             list.Add(command);
41             return this;
42         }
43         public void Remove(Command command)
44         {
45             list.Remove(command);
46         }
47         public void Notify()
48         {
49              list.All(x => { x.ExecCommand(); return true; });
50         }
51     }
52 }
53  static void 命令模式()
54         {
55             Execer execer = new Execer();
56             Command c1 = new CommandOne(execer);
57             Command c2 = new CommandTwo(execer);
58             var builder = new DesignModel.命令模式.Builder();
59             builder.SetBuilder(c1).SetBuilder(c2).Notify();
60          }

View Code

优点：

1可以设计命令队列；

2允许命令接收方否决命令；

3新增具体命令类不影响其它部分。