bindService获取后台服务

package com.example.mybindservicetest; import androidx.appcompat.app.AppCompatActivity; import android.content.ComponentName; 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.Toast; import java.util.Random; public class MainActivity extends AppCompatActivity { private MyService service = null; private boolean isBound = false; // // private final Random generator = new Random(); private Button btn; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); btn=(Button) findViewById(R.id.button); Intent intent = new Intent(this, MyService.class); bindService(intent, conn, BIND_AUTO_CREATE); btn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { int num=service.getRandomNumber(); Toast.makeText(MainActivity.this,"获取到彩票号为:"+num,Toast.LENGTH_LONG).show(); } }); } private ServiceConnection conn = new ServiceConnection() { @Override public void onServiceConnected(ComponentName name, IBinder binder) { isBound = true; MyService.myBinder myBinder = (MyService.myBinder)binder; service = myBinder.getService(); Log.i("DemoLog", "ActivityA onServiceConnected"); // int num = service.getRandomNumber(); // Log.i("DemoLog", "ActivityA 中调用 TestService的getRandomNumber方法, 结果: " + num); } @Override public void onServiceDisconnected(ComponentName name) { isBound = false; Log.i("DemoLog", "ActivityA onServiceDisconnected"); } }; @Override protected void onDestroy() { super.onDestroy(); Log.i("DemoLog", "ActivityA -> onDestroy"); } }