CAD—Keyboard事件处理

      在之前的博客随笔中提到过CAD中鼠标的悬浮功能，后来就一直在想可不可以在CAD中触发Key事件，之后在Kean的一篇博文中提到过关于捕捉键盘事件，可惜不太实用，比如想通过键盘的上下键来移动一个实体。效果就像下面这样

 

     后来就想用钩子实现吧，然后在网上找KeyHook之类的信息，现成的代码真是太多了，现在贴出这部分网上找到的代码

 1     public class KeyboardHook
 2     {
 3         public event KeyEventHandler KeyDownEvent;
 4 
 5         public delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);
 6 
 7         static int hKeyboardHook = 0;//声明键盘钩子处理的初始值
 8 
 9         public const int WH_KEYBOARD_LL = 13;
10 
11         HookProc KeyboardHookProcedure;
12 
13         [StructLayout(LayoutKind.Sequential)]
14         public class KeyboardHookStruct
15         {
16             public int vkCode;
17             public int scanCode;
18             public int flags;
19             public int time;
20             public int dwExtraInfo;
21         }
22 
23         [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
24         public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);
25 
26         [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
27         public static extern bool UnhookWindowsHookEx(int idHook);
28 
29         [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
30         public static extern int CallNextHookEx(int idHook, int nCode, Int32 wParam, IntPtr lParam);
31 
32         public void Start()
33         {
34             if (hKeyboardHook == 0)
35             {
36                 KeyboardHookProcedure = new HookProc(KeyboardHookProc);
37                 hKeyboardHook = SetWindowsHookEx(WH_KEYBOARD_LL, KeyboardHookProcedure, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0);
38 
39                 if (hKeyboardHook == 0)
40                 {
41                     Stop();
42                     throw new Exception("安装键盘钩子失败 ");
43                 }
44             }
45         }
46 
47         public void Stop()
48         {
49             bool retKeyboard = true;
50 
51             if (hKeyboardHook != 0)
52             {
53                 retKeyboard = UnhookWindowsHookEx(hKeyboardHook);
54                 hKeyboardHook = 0;
55             }
56             if (!retKeyboard) throw new Exception("卸载钩子失败！");
57         }
58 
59         [DllImport("user32")]
60         public static extern int ToAscii(int uVirtKey,
61             int uScanCode,
62             byte[] lpbKeyState,
63             byte[] lpwTransKey,
64             int fuState);
65 
66         [DllImport("user32")]
67         public static extern int GetKeyboardState(byte[] pbKeyState);
68 
69         private const int WM_KEYDOWN = 0x100;
70         private const int WM_KEYUP = 0x101;
71         private const int WM_SYSKEYDOWN = 0x104;
72         private const int WM_SYSKEYUP = 0x105;
73 
74         private int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)
75         {
76             if ((nCode >= 0) && (KeyDownEvent != null || KeyUpEvent != null || KeyPressEvent != null))
77             {
78                 KeyboardHookStruct MyKeyboardHookStruct = (KeyboardHookStruct)Marshal.PtrToStructure(lParam, typeof(KeyboardHookStruct));
79 
80                 //键盘压下事件
81                 if (KeyDownEvent != null && (wParam == WM_KEYDOWN || wParam == WM_SYSKEYDOWN))
82                 {
83                     Keys keyData = (Keys)MyKeyboardHookStruct.vkCode;
84                     KeyEventArgs e = new KeyEventArgs(keyData);
85                     KeyDownEvent(this, e);
86                 }
87             }
88 
89             return CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);
90         }
91 
92         ~KeyboardHook()
93         {
94             Stop();
95         }
96     }

     编译成dll，然后将其加载到你的CAD项目中，在CAD中要实现的代码很容易。

  1         private KeyboardHook k_hook;
  2         Document doc = AsApp.DocumentManager.MdiActiveDocument;
  3         Database db = AsApp.DocumentManager.MdiActiveDocument.Database;
  4         Editor ed = AsApp.DocumentManager.MdiActiveDocument.Editor;
  5         ObjectId entId = ObjectId.Null;
  6 
  7         [CommandMethod("MoveEnt", CommandFlags.UsePickSet)]
  8         public void MoveEnt()
  9         {
 10 
 11             PromptSelectionResult res = ed.SelectImplied();
 12             if (PromptStatus.OK != res.Status) return;
 13 
 14             ObjectIdCollection ids = new ObjectIdCollection(res.Value.GetObjectIds());
 15             if (ids.Count <= 0) return;
 16 
 17             //注册键盘事件
 18             try
 19             {
 20                 k_hook = new KeyboardHook();
 21                 k_hook.KeyDownEvent += new KeyEventHandler(hook_KeyDown);
 22                 k_hook.Start();
 23             }
 24             catch(System.Exception ex)
 25             {
 26                 ed.WriteMessage("\n注册键盘事件错误信息：" + ex.Message);
 27                 return;
 28             }
 29 
 30             Transaction tr = db.TransactionManager.StartTransaction();
 31             using (tr)
 32             {
 33                 BlockTable bt = (BlockTable)tr.GetObject(db.BlockTableId, OpenMode.ForRead);
 34                 BlockTableRecord btr = (BlockTableRecord)tr.GetObject(db.CurrentSpaceId, OpenMode.ForRead);
 35 
 36                 //先仅考虑一个实体
 37                 entId = ids[0];
 38             }
 39         }
 40 
 41         private void hook_KeyDown(object sender, KeyEventArgs e)
 42         {
 43             if (ObjectId.Null == entId) return;
 44             Transaction tr = db.TransactionManager.StartTransaction();
 45             try
 46             {
 47                 using (tr)
 48                 {
 49                     using (DocumentLock docLock = doc.LockDocument())
 50                     {
 51                         BlockTable bt = (BlockTable)tr.GetObject(db.BlockTableId, OpenMode.ForRead);
 52                         BlockTableRecord btr = (BlockTableRecord)tr.GetObject(db.CurrentSpaceId, OpenMode.ForRead);
 53                         Entity ent = tr.GetObject(entId, OpenMode.ForWrite) as Entity; //待移动的实体
 54 
 55                         Point3d entPos = Point3d.Origin;
 56                         if (ent is Circle) //移动一个圆
 57                         {
 58                             Circle c = ent as Circle;
 59                             entPos = c.Center;
 60                         }
 61                         if (e.KeyCode == Keys.Up) //向上移
 62                         { 
 63                             Matrix3d matrix = Matrix3d.Displacement(new Vector3d(0, 10, 0));
 64                             ent.TransformBy(matrix);
 65                         }
 66                         else if (e.KeyCode == Keys.Down)
 67                         {
 68                             Matrix3d matrix = Matrix3d.Displacement(new Vector3d(0, -10, 0));
 69                             ent.TransformBy(matrix);
 70                         }
 71                         else if (e.KeyCode == Keys.Left)
 72                         {
 73                             Matrix3d matrix = Matrix3d.Displacement(new Vector3d(-10, 0, 0));
 74                             ent.TransformBy(matrix);
 75                         }
 76                         else if (e.KeyCode == Keys.Right)
 77                         {
 78                             Matrix3d matrix = Matrix3d.Displacement(new Vector3d(10, 0, 0));
 79                             ent.TransformBy(matrix);
 80                         }
 81                         else if (e.KeyCode == Keys.Escape)
 82                         {
 83                             ed.WriteMessage("\n按键操作取消");
 84                             k_hook.Stop();
 85                         }
 86                         else
 87                         {
 88                             ed.WriteMessage("\n可以通过上下键来控制实体的移动！");
 89                         }
 90 
 91                         //提交
 92                         tr.Commit();
 93                         ed.UpdateScreen();
 94                     }
 95                 }
 96             }
 97             catch (Autodesk.AutoCAD.Runtime.Exception ex)
 98             {
 99                 ed.WriteMessage(" \n异常：" + ex.Message);
100             }
101         }
102 
103         ~KeyMoveEn()
104         {
105             k_hook.Stop();
106         }

     运行以后便是上面的贴图展现出来的效果。(看了上面的效果，感觉是不是可以实现一个CAD版本的俄罗斯方块游戏)