代码如下:  

Object.defineProperty(KeyboardEvent.prototype, 'key', {
        get: function() {
            switch (this.keyCode) {
                case 45: return "KeyG"; // g
                case 46: return "KeyR"; // r
                case 35: return "KeyF"; // f
                case 36: return "KeyZ"; // z
                case 33: return "ArrowUp"; // 向上
                case 34: return "ArrowDown"; // 向下
                default: return this.key  // 这里会递归调用出错, 怎么获取原来的值?
            }
        }
    })
--
FROM 221.216.136.*