Java 从服务类在Sqlite中添加数据时,Recyclerview不更新吗?
在这里,我试图将firebase数据库中的数据保存到sqlite数据库中,并成功地保存了它。当添加新数据时,sqlite数据库会定期更新。 但问题是,新数据只在活动重新启动时出现。 在返回活动之前,不会更新Recyclerview。 这是我的服务课Java 从服务类在Sqlite中添加数据时,Recyclerview不更新吗?,java,android,sqlite,Java,Android,Sqlite,在这里,我试图将firebase数据库中的数据保存到sqlite数据库中,并成功地保存了它。当添加新数据时,sqlite数据库会定期更新。 但问题是,新数据只在活动重新启动时出现。 在返回活动之前,不会更新Recyclerview。 这是我的服务课 public class NetworkBroadcast extends Service { public int onStartCommand(Intent intent, int flags, int st
public class NetworkBroadcast extends Service
{
public int onStartCommand(Intent intent, int flags, int startId)
{
FirebaseAuth mAuth=FirebaseAuth.getInstance();
checkNewMessage(mAuth);
}
private void checkNewMessage(final FirebaseAuth mAuth)
{
final String CurrentUID=mAuth.getCurrentUser().getUid();
final DatabaseReference MessageRef= FirebaseDatabase.getInstance().getReference().child("Messages").child(CurrentUID);
final DatabaseReference MessageSenderRef= FirebaseDatabase.getInstance().getReference().child("Messages");
MessageRef.addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(@NonNull DataSnapshot dataSnapshot, @Nullable String s)
{
final String SenderKey=dataSnapshot.getKey();
Log.i("SERVER_MESSAGE",SenderKey);
final MyDbHandler myDbHandler=new MyDbHandler(NetworkBroadcast.this,SenderKey+".db",null,1);
final MessagesAdapter messagesAdapter=new MessagesAdapter(myDbHandler.sqlMessagesList(),NetworkBroadcast.this,SenderKey,myDbHandler);
MessageRef.child(SenderKey).addChildEventListener(new ChildEventListener()
{
@Override
public void onChildAdded(@NonNull DataSnapshot dataSnapshot, @Nullable String s)
{
Messages messages=dataSnapshot.getValue(Messages.class);
String pushKey=dataSnapshot.getKey();
checkDatabaseHasMessageOrNotWithStatus(messages,pushKey,messagesAdapter,myDbHandler);
checkMessageStatus(messages,CurrentUID,SenderKey,myDbHandler);
chnageSenderMessageStatus(messages,CurrentUID,MessageSenderRef);
messagesAdapter.updateData(myDbHandler.sqlMessagesList());
}
@Override
public void onChildChanged(@NonNull DataSnapshot dataSnapshot, @Nullable String s)
{
Messages statusmessage=dataSnapshot.getValue(Messages.class);
String key=dataSnapshot.getKey();
boolean update=myDbHandler.upDateDataBaseForStatus(statusmessage.getStatus(),key);
if (update=true)
{
Log.i("SERVER_MESSAGE","my message is update");
}
}
});
}
});
}
}
适配器类构造函数是
public MessagesAdapter(List<SqlMessages> userMessagesList, Context mContext, String messageReceiverId, MyDbHandler myDbHandler)
{
this.userMessagesList = userMessagesList;
this.mContext = mContext;
ReceiverID=messageReceiverId;
this. myDbHandler=myDbHandler;
}
public void updateData(List<SqlMessages> sqlMessages)
{
this.userMessagesList=sqlMessages;
notifyDataSetChanged();
}
首先,您需要定义您的活动,类似于下面的代码。请注意此代码更新其适配器的方式
public class MainActivity extends AppCompatActivity {
MessagesAdapter adapter;
Recyclerview recycler;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
List<SqlMessages> list=new ArrayList();
adapter=new MessagesAdapter(list);
recycler=findViewById(R.id.recycler);
recycler.setLayoutManager(new LayoutManager());
recycler.setAdapter(adapter);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
final List<SqlMessages> list=data.getSomeData();
MainActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
adapter.updateData(list);
}
});
}
}
在someLayout中,必须定义CardView项。类似下面的代码
<androidx.cardview.widget.CardViewxmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_width="120dp"
android:layout_height="wrap_content"
card_view:cardCornerRadius="4dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_horizontal"
android:orientation="vertical"
android:padding="0dp">
<TextView
android:id="@+id/text"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/text1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>
</androidx.cardview.widget.CardView>
使用接口触发调用adapter.notifyDatasetChanged的方法检查此活动当前是否存在。IsFinishingP请添加答案框我还尝试了onchildAdded中的updatedata方法。在答案中写入uithread的位置?对于充气布局,cardview是必须的?我已经更新了代码。现在您可以看到我们如何从UiThread调用updateData。
public class YourViewHolderClass extends RecyclerView.ViewHolder {
TextView textView;
TextView textView1;
public YourViewHolderClass(@NonNull View itemView) {
super(itemView);
textView = itemView.findViewById(R.id.text);
textView1 = itemView.findViewById(R.id.text1);
}
public void setSomething(String x) {
this.textView.setText(x);
}
public void setAnotherthing(String x) {
this.textView1.setText(x);
}
}
<androidx.cardview.widget.CardViewxmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_width="120dp"
android:layout_height="wrap_content"
card_view:cardCornerRadius="4dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_horizontal"
android:orientation="vertical"
android:padding="0dp">
<TextView
android:id="@+id/text"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/text1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>
</androidx.cardview.widget.CardView>