[英]Update value in Firebase Realtime Database (Offline) - Android
I need update one value which is the sum of executed tests in my Android application. 我需要更新一个值,该值是我的Android应用程序中已执行测试的总和。 I thought, that I can add each device and value of executed tests for this devices. 我以为我可以添加每个设备以及为此设备执行的测试的值。 Next I would like to get sum for all devices. 接下来,我想获取所有设备的总和。
Now I have: 我现在有:
import android.content.Intent;
import android.provider.Settings;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
public class MainActivity extends AppCompatActivity {
private Button startTestButton;
private FirebaseDatabase database;
private DatabaseReference myRef;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setTitle("Test");
Answers.getInstance().reset();
database = FirebaseDatabase.getInstance();
myRef = FirebaseDatabase.getInstance().getReference();
myRef.child("test").child("devices").child(Settings.Secure.ANDROID_ID).setValue(1);
startTestButton = findViewById(R.id.buttonStartTest);
startTestButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
openQuestion1Activity();
}
});
}
public void openQuestion1Activity(){
Intent intent = new Intent(this, Question1.class);
startActivity(intent);
}
}
I need offline database and sync values when I have internet connection. 连接互联网后,我需要脱机数据库并同步值。 How can I do this? 我怎样才能做到这一点? Can I please for example? 我可以举个例子吗?
将FirebaseDatabase.getInstance().setPersistenceEnabled(true)
放在应用程序中首次调用FirebaseDatabase.getInstance()
之前。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.