如何从类 FirebaseMessagingService 更改 MainActivity 中的 TextView tx

Question

我做过研究，但没有成功。任何人都可以帮我如何从类FirebaseMessagingService更改 MainActivity 中的TextView txtView.该程序似乎没有错误，但是在Firebase控制台之后，应用程序被txt.setText(a(关闭(销毁(;

主要活动.java ：

package com.islk.gcmexample;
import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import com.google.firebase.iid.FirebaseInstanceId;
import java.util.ArrayList;
import java.util.Arrays;
public class MainActivity extends AppCompatActivity {
ListView listView ;
ArrayAdapter<String> adapter;
ArrayList<String> arrayList;
public static Context contextA;
private static final String TAG = "MainActivity";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
contextA = this;
setContentView(R.layout.activity_main);
TextView txtView = (TextView) findViewById(R.id.textView);
txtView.setText("Hello i1");
listView = (ListView) findViewById(R.id.list);
String[] values = new String[] { "Android List View",
"Adapter implementation",
"Simple List View In Android",
"Create List View Android",
"Android Example",
"List View Source Code",
"List View Array Adapter",
"Android Example List View"
};
arrayList = new ArrayList<>(Arrays.asList(values));
adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, android.R.id.text1, arrayList);
listView.setAdapter(adapter);
arrayList.add("iSLK");
adapter.notifyDataSetChanged();
setNotificationData(getIntent().getExtras());
Utils.showToast(MainActivity.this, "FB: hello");
Button btnShowToken = (Button) findViewById(R.id.button_show_token);
btnShowToken.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String token = FirebaseInstanceId.getInstance().getToken();
Log.d(TAG, "Token: " + token);
listView.setAdapter(null);
Toast.makeText(MainActivity.this, token, Toast.LENGTH_SHORT).show();
jano();
}
});
}
private void jano(){
TextView txtView = (TextView) findViewById(R.id.textView);
txtView.setText("Hello i2");
}


}

FirebaseMessagingService.java ：

package com.islk.gcmexample;
import android.app.Activity;
import android.util.Log;
import android.widget.TextView;
import com.google.firebase.messaging.RemoteMessage;
import static com.islk.gcmexample.MainActivity.contextA;
public class FirebaseMessagingService extends com.google.firebase.messaging.FirebaseMessagingService{
private static final String TAG = "MyFirebaseMsgService";
TextView txt = (TextView) ((Activity)contextA).findViewById(R.id.textView);
@Override
public void onMessageReceived(RemoteMessage remoteMessage) {
Log.d(TAG, "FB: From: " + remoteMessage.getFrom());
sendNotification(remoteMessage);
if (remoteMessage.getData().size() > 0) {
Log.d(TAG, "FB: Message data payload: " + remoteMessage.getData());
if (/* Check if data needs to be processed by long running job */ true) {
} else {
}
}
// Check if message contains a notification payload.
if (remoteMessage.getNotification() != null) {
Log.d(TAG, "FB: Message Notification Body: " + remoteMessage.getNotification().getBody());
}
}
private void sendNotification(RemoteMessage remoteMessage) {
setTextViewToModify("Hello i3");
}
public void setTextViewToModify (String a){
txt.setText(a);
}
}

MyFirebaseInstanceIDService.java ：

package com.islk.gcmexample;
import android.util.Log;
import com.google.firebase.iid.FirebaseInstanceId;
import com.google.firebase.iid.FirebaseInstanceIdService;
public class MyFirebaseInstanceIDService extends FirebaseInstanceIdService {
private static final  String TAG = "MyFirebaseInsIDService";
@Override
public void onTokenRefresh() {
//Get update token
String refreshedToken = FirebaseInstanceId.getInstance().getToken();
Log.d(TAG, "New Token :" + refreshedToken);
//sendRegistrationToServer(refreshedToken);

// You can save the token into third party server to do anything you want
}
}

activity_main.xml ：

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="@+id/button_show_token"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Token and Clear Alarms EVENTS"
tools:layout_editor_absoluteX="16dp"
tools:layout_editor_absoluteY="2dp" />
<ListView
android:id="@+id/list"
android:layout_height="wrap_content"
android:layout_width="match_parent"
tools:layout_editor_absoluteX="16dp"
tools:layout_editor_absoluteY="50dp" >
</ListView>
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:text="TextView"
app:layout_constraintEnd_toEndOf="parent"
tools:layout_editor_absoluteY="16dp" />

</android.support.constraint.ConstraintLayout>

提前谢谢你。

Answer 1

您可以使用 LocalBroadcastManager 将任何值从服务发送到主活动。

Intent intent = new Intent("filter_string");
intent.putExtra("key", "My Data");
// put your all data using put extra 
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);

在您的主要活动中

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LocalBroadcastManager lbm = LocalBroadcastManager.getInstance(this);
lbm.registerReceiver(receiver, new IntentFilter("filter_string"));
}
public BroadcastReceiver receiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
if (intent != null) {
String str = intent.getStringExtra("key");
}
}
};
Hopefully this will solve your problem.