KeyExamine.cs

  //-------------------------------------------
  // KeyExamine.cs (C) 2001 by Charles Petzold
  //-------------------------------------------
  using System;
  using System.Drawing;
  using System.Windows.Forms;

  public class KeyExamine: Form 
  {
      public static void Main() 
      {
          Application.Run(new KeyExamine());
      }

      // Определение перечислений и структур
      // для хранения событий клавиш

      enum EventType
      {
          None,
          KeyDown,
          KeyUp,
          KeyPress
      }
      struct KeyEvent
      {
          public EventType evttype;
          public EventArgs evtargs;
      }

      // Хранилище для событий клавиш

      const int  iNumLines    = 25;
      int        iNumValid    = 0;
      int        iInsertIndex = 0;
      KeyEvent[] akeyevt = new KeyEvent[iNumLines];

      // Позиционирование текста

      int xEvent, xChar, xCode, xMods, xData, 
          xShift, xCtrl, xAlt, xRight;
     
      public KeyExamine() 
      {
          Text = "Key Examine";
          BackColor = SystemColors.Window;
          ForeColor = SystemColors.WindowText;

          xEvent = 0;
          xChar  = xEvent + 5 * Font.Height;
          xCode  = xChar  + 5 * Font.Height;
          xMods  = xCode  + 8 * Font.Height;
          xData  = xMods  + 8 * Font.Height;
          xShift = xData  + 8 * Font.Height;
          xCtrl  = xShift + 5 * Font.Height;
          xAlt   = xCtrl  + 5 * Font.Height;
          xRight = xAlt   + 5 * Font.Height;

          ClientSize  = new Size(xRight, Font.Height * (iNumLines + 1));
          FormBorderStyle = FormBorderStyle.Fixed3D;
          MaximizeBox = false;
      }
      protected override void OnKeyDown(KeyEventArgs kea)
      {
          akeyevt[iInsertIndex].evttype = EventType.KeyDown;
          akeyevt[iInsertIndex].evtargs = kea;
          OnKey();
      }
      protected override void OnKeyUp(KeyEventArgs kea)
      {
          akeyevt[iInsertIndex].evttype = EventType.KeyUp;
          akeyevt[iInsertIndex].evtargs = kea;
          OnKey();
      }
      protected override void OnKeyPress(KeyPressEventArgs kpea)
      {
          akeyevt[iInsertIndex].evttype = EventType.KeyPress;
          akeyevt[iInsertIndex].evtargs = kpea;
          OnKey();
      }
      void OnKey()
      {
          if(iNumValid < iNumLines)
          {
              Graphics grfx = CreateGraphics();
              DisplayKeyInfo(grfx, iInsertIndex, iInsertIndex);
              grfx.Dispose();
          }
          else
          {
              ScrollLines();
          }
          iInsertIndex = (iInsertIndex + 1) % iNumLines;
          iNumValid = Math.Min(iNumValid + 1, iNumLines);
      }
      protected virtual void ScrollLines()
      {
          Rectangle rect = new Rectangle(0, Font.Height, 
                                         ClientSize.Width,
                                         ClientSize.Height - Font.Height);

          // Здесь хорошо бы иметь возможность прокрутки!

          Invalidate(rect);
      }
      protected override void OnPaint(PaintEventArgs pea)
      {
          Graphics grfx = pea.Graphics;

          BoldUnderline(grfx, "Event",     xEvent, 0);
          BoldUnderline(grfx, "KeyChar",   xChar,  0);
          BoldUnderline(grfx, "KeyCode",   xCode,  0);
          BoldUnderline(grfx, "Modifiers", xMods,  0);
          BoldUnderline(grfx, "KeyData",   xData,  0);
          BoldUnderline(grfx, "Shift",     xShift, 0);
          BoldUnderline(grfx, "Control",   xCtrl,  0);
          BoldUnderline(grfx, "Alt",       xAlt,   0);

          if(iNumValid < iNumLines)
          {
              for (int i = 0; i < iNumValid; i++)
                  DisplayKeyInfo(grfx, i, i);
          }
          else
          {
              for (int i = 0; i < iNumLines; i++)
                  DisplayKeyInfo(grfx, i,(iInsertIndex + i) % iNumLines);
          }
      }
      void BoldUnderline(Graphics grfx, string str, int x, int y)
      {
          // Рисуем полужирный текст

          Brush brush = new SolidBrush(ForeColor);
          grfx.DrawString(str, Font, brush, x, y);
          grfx.DrawString(str, Font, brush, x + 1, y);

          // Подчеркивание текста

          SizeF sizef = grfx.MeasureString(str, Font);
          grfx.DrawLine(new Pen(ForeColor), x, y + sizef.Height,
                                        x + sizef.Width, y + sizef.Height);
      }
      void DisplayKeyInfo(Graphics grfx, int y, int i)
      {
          Brush br = new SolidBrush(ForeColor);
          y = (1 + y) * Font.Height;    // Преобразуем y в координаты пикселя

          grfx.DrawString(akeyevt[i].evttype.ToString(),
                          Font, br, xEvent, y);

          if(akeyevt[i].evttype == EventType.KeyPress)
          {
              KeyPressEventArgs kpea = 
                                 (KeyPressEventArgs) akeyevt[i].evtargs;

              string str = String.Format("\x202D{0} (0x{1:X4})",
                                        kpea.KeyChar, (int) kpea.KeyChar);
              grfx.DrawString(str, Font, br, xChar, y);
          }
          else
          {
              KeyEventArgs kea = (KeyEventArgs) akeyevt[i].evtargs;

              string str = String.Format("{0} ({1})", 
                                        kea.KeyCode, (int) kea.KeyCode);
              grfx.DrawString(str, Font, br, xCode, y);
              grfx.DrawString(kea.Modifiers.ToString(), Font, br, xMods, y);
              grfx.DrawString(kea.KeyData.ToString(), Font, br, xData, y);
              grfx.DrawString(kea.Shift.ToString(), Font, br, xShift, y);
              grfx.DrawString(kea.Control.ToString(), Font, br, xCtrl,  y);
              grfx.DrawString(kea.Alt.ToString(), Font, br, xAlt,   y);
          }
      }
  }