Service与Activity之间通信

https://blog.youkuaiyun.com/xiaanming/article/details/9750689#commentBox

这个讲的太好了直接看这个吧

新建一个msgService类继承Serivice

import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;

public class MsgService extends Service {
    //进度条的最大值
    public static final int MAX_PROGRESS = 100;
    //进度条的进度值
    private int progress = 0;

    /**
     * 增加get()方法，供Activity调用
     *
     * @return 下载进度
     */
    public int getProgress() {
        return progress;
    }

    /**
     * 模拟下载任务，每秒钟更新一次
     */
    public void startDownLoad() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                while (progress < MAX_PROGRESS) {
                    progress += 5;
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }).start();
    }

    /**
     * 返回一个Binder对象
     */
    @Override
    public IBinder onBind(Intent intent) {
        return new MsgBinder();
    }

    public class MsgBinder extends Binder {
        /**
         * 获取当前Service的实例
         *
         * @return
         */
        public MsgService getService() {
            return MsgService.this;
        }
    }

}

Activity

import androidx.appcompat.app.AppCompatActivity;

import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.Toast;


public class MainActivity extends AppCompatActivity {
    private MsgService msgService;
    private int progress = 0;
    private ProgressBar mProgressBar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //绑定service
        Intent intent = new Intent(this, MsgService.class);
        bindService(intent, conn, Context.BIND_AUTO_CREATE);
        mProgressBar = findViewById(R.id.progressBar1);
        Button mButton = findViewById(R.id.button1);
        mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //开始下载
                msgService.startDownLoad();
                //监听进度
                listenProgress();
            }
        });

    }

    //造ServiceConnection　对象　重写内部方法
    ServiceConnection conn = new ServiceConnection() {

        @Override
        public void onServiceDisconnected(ComponentName name) {
        }

        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            //返回一个MsgService对象
            Log.i("godv", "onServiceConnected" + service);
            msgService = ((MsgService.MsgBinder) service).getService();

        }
    };


    /**
     * 监听进度，每秒钟获取调用MsgService的getProgress()方法来获取进度，更新UI
     */
    public void listenProgress() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                while (progress < MsgService.MAX_PROGRESS) {
//                    progress = msgService.getProgress();
//                    mProgressBar.setProgress(progress);
                    try {
                        Thread.sleep(1000);
                        MainActivity.this.runOnUiThread(new Runnable() {
                            @Override
                            public void run() {
                                Toast.makeText(MainActivity.this, "godv", Toast.LENGTH_SHORT).show();
                            }
                        });

                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }).start();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unbindService(conn);
    }
}

注册

<service android:name="com.example.service_count.MsgService" />