var keymap = (UE.keymap = {
  Backspace: 8,
  Tab: 9,
  Enter: 13,

  Shift: 16,
  Control: 17,
  Alt: 18,
  CapsLock: 20,

  Esc: 27,

  Spacebar: 32,

  PageUp: 33,
  PageDown: 34,
  End: 35,
  Home: 36,

  Left: 37,
  Up: 38,
  Right: 39,
  Down: 40,

  Insert: 45,

  Del: 46,

  NumLock: 144,

  Cmd: 91,

  "=": 187,
  "-": 189,

  b: 66,
  i: 73,
  //回退
  z: 90,
  y: 89,
  //粘贴
  v: 86,
  x: 88,

  s: 83,

  n: 78
});