所谓矩阵键盘是指：用m条I/O线组成行输入口，用n条I/O线组成列输入口，来控制mXn个键盘，每个键盘都有自己的坐标（m，n）。-The so-called matrix the keyboard is to point to: use article m I/O it quad input port, with n I/O wire column input port, to control mXn a keyboard, each keyboard has its own coordinat