前言
Android设备连接物理键盘其实是个挺小众的需求，其实Android设备本身就是支持物理键盘，dispatchKeyEvent()这个方法就可以监听物理键盘，这里提供一个封装的类，解析键盘事件。有很多事件，具体可以去看KeyEvent这个类的源码，我这里只处理的数字键盘。
实现方式
1.键盘事件解析类
public class DispatchKeyResolver {
public OnKeyInputListener keyInputListener;
public void resolveKeyEvent(KeyEvent event) {
getInputChar(event);
}
public void getInputChar(KeyEvent event) {
int keyCode = event.getKeyCode();
char aChar;
if(keyCode >= KeyEvent.KEYCODE_0 && keyCode <= KeyEvent.KEYCODE_9) {
//数字
aChar = (char) ('0' + keyCode - KeyEvent.KEYCODE_0);
} else if(keyCode >= KeyEvent.KEYCODE_NUMPAD_0 && keyCode <= KeyEvent.KEYCODE_NUMPAD_9) {
//数字
aChar = (char) ('0' + keyCode - KeyEvent.KEYCODE_NUMPAD_0);
} else {
//其他符号
switch(keyCode) {
case KeyEvent.KEYCODE_PERIOD:
aChar = '.';
break;
case KeyEvent.KEYCODE_NUMPAD_DOT:
aChar = '.';
break;
default:
return;
}
}
keyInputListener.onKeyInput(aChar);
}
public void setKeyInputListener(OnKeyInputListener keyInputListener) {
this.keyInputListener = keyInputListener;
}
public interface OnKeyInputListener {
void onKeyInput(char aChar);
}
}
2.设置监听
DispatchKeyResolver dr = new DispatchKeyResolver();
//设置事件回调
dr.setKeyInputListener(...)
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
//物理键确定，并且是按下的行为（避免两次响应）
if(event.getKeyCode() == KeyEvent.KEYCODE_ENTER && event.getAction() == KeyEvent.ACTION_DOWN){
dr.resolveKeyEvent(event)
}
return super.dispatchKeyEvent(event);
}
