android中（activity中）按键事件的处理

package com.example.yaokong;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.KeyEvent;
import android.view.SurfaceView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public String coder(String message){
        // 依次替换 AA、CC、EE
        String str = message.replaceAll("EE", "EEOE")
                .replaceAll("AA", "EEOA")
                .replaceAll("CC", "EEOC");
        str="AA"+str+"CC";
        return str;
    }
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        int code=event.getKeyCode();
        String str="";
        // 将键码发送到服务器
        switch (code){
            case 19:
                str= coder("key=24");//按键转码，上
                //connect.sendData(str);
                //sendData(str);
                Toast.makeText(this,str, Toast.LENGTH_SHORT).show();
                break;
            case 21:
                str= coder("key=27");//按键转码，左
                Toast.makeText(this,str, Toast.LENGTH_SHORT).show();
                // connect.sendData(str);
                //sendData(str);
                // executor.execute(new ReceiveThread());
                break;
            case 23:
                str= coder("key=28");//按键转码
                Toast.makeText(this,str, Toast.LENGTH_SHORT).show();
                //connect.sendData(str);
                //sendData(str);
                //executor.execute(new ReceiveThread());
                break;
            case 22:
                str= coder("key=26");//按键转码，右
                Toast.makeText(this,str, Toast.LENGTH_SHORT).show();
                //connect.sendData(str);
                //sendData(str);
                //executor.execute(new ReceiveThread());
                break;
            case 20:
                str= coder("key=25");//按键转码，下
                Toast.makeText(this,str, Toast.LENGTH_SHORT).show();
                // connect.sendData(str);
                // sendData(str);
                // executor.execute(new ReceiveThread());
                break;
            case 7:
                str= coder("key=21");//按键转码，主界面
                Toast.makeText(this,str, Toast.LENGTH_SHORT).show();
                //connect.sendData(str);
                //sendData(str);
                // executor.execute(new ReceiveThread());
                break;
            case 67:
                str= coder("key=20");//按键转码，返回
                Toast.makeText(this,str, Toast.LENGTH_SHORT).show();
                //connect.sendData(str);
                //sendData(str);
                // executor.execute(new ReceiveThread());
                break;

        }
        return super.onKeyDown(keyCode, event);
    }


}

如何将一个按键事件传到不同的页面进行处理？不知道暂时。

如何在多页面共用一个socket,暂时不知道。