Notifications Tutorial Part 1

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    android:padding="16dp"
    tools:context="com.codinginflow.notificationsexample.MainActivity">

    <EditText
        android:id="@+id/edit_text_title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Title" />

    <EditText
        android:id="@+id/edit_text_message"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Message" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="sendOnChannel1"
        android:text="Send on Channel 1" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="sendOnChannel2"
        android:text="Send on Channel 2" />

</LinearLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.codinginflow.notificationsexample">

    <application
        android:name=".App"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

App.java

package com.codinginflow.notificationsexample;

import android.app.Application;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.os.Build;


public class App extends Application {
    public static final String CHANNEL_1_ID = "channel1";
    public static final String CHANNEL_2_ID = "channel2";

    @Override
    public void onCreate() {
        super.onCreate();

        createNotificationChannels();
    }

    private void createNotificationChannels() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel1 = new NotificationChannel(
                    CHANNEL_1_ID,
                    "Channel 1",
                    NotificationManager.IMPORTANCE_HIGH
            );
            channel1.setDescription("This is Channel 1");

            NotificationChannel channel2 = new NotificationChannel(
                    CHANNEL_2_ID,
                    "Channel 2",
                    NotificationManager.IMPORTANCE_LOW
            );
            channel2.setDescription("This is Channel 2");

            NotificationManager manager = getSystemService(NotificationManager.class);
            manager.createNotificationChannel(channel1);
            manager.createNotificationChannel(channel2);
        }
    }
}

MainActivity.java

package com.codinginflow.notificationsexample;

import android.app.Notification;
import android.support.v4.app.NotificationCompat;
import android.support.v4.app.NotificationManagerCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

import static com.codinginflow.notificationsexample.App.CHANNEL_1_ID;
import static com.codinginflow.notificationsexample.App.CHANNEL_2_ID;

public class MainActivity extends AppCompatActivity {
    private NotificationManagerCompat notificationManager;
    private EditText editTextTitle;
    private EditText editTextMessage;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        notificationManager = NotificationManagerCompat.from(this);

        editTextTitle = findViewById(R.id.edit_text_title);
        editTextMessage = findViewById(R.id.edit_text_message);
    }

    public void sendOnChannel1(View v) {
        String title = editTextTitle.getText().toString();
        String message = editTextMessage.getText().toString();

        Notification notification = new NotificationCompat.Builder(this, CHANNEL_1_ID)
                .setSmallIcon(R.drawable.ic_one)
                .setContentTitle(title)
                .setContentText(message)
                .setPriority(NotificationCompat.PRIORITY_HIGH)
                .setCategory(NotificationCompat.CATEGORY_MESSAGE)
                .build();

        notificationManager.notify(1, notification);
    }

    public void sendOnChannel2(View v) {
        String title = editTextTitle.getText().toString();
        String message = editTextMessage.getText().toString();

        Notification notification = new NotificationCompat.Builder(this, CHANNEL_2_ID)
                .setSmallIcon(R.drawable.ic_two)
                .setContentTitle(title)
                .setContentText(message)
                .setPriority(NotificationCompat.PRIORITY_LOW)
                .build();

        notificationManager.notify(2, notification);
    }
}

This project works on its own but when I add the code to my existing project and click the button NOTHING happens! Idk why. No error, just nothing happens. I'm so confused.

Do you have everything right in your code? Maybe did you forget that activity_main.xml has the function onClick with that it starts the function sendChannel1. That was my problem and after fixing that my code worked fine.

This project works on its own but when I add the code to my existing project and click the button NOTHING happens! Idk why. No error, just nothing happens. I'm so confused.

Do you have everything right in your code? Maybe did you forget that activity_main.xml has the function onClick with that it starts the function sendChannel1. That was my problem and after fixing that my code worked fine.

i found the problem , it was that i didn't put name=.app in the manifest so the channels weren't created in the first place
thank you for responding

It doens't work for me I don't have to:
import android.support.v4.app.NotificationCompat;
import android.support.v4.app.NotificationManagerCompat;
and I think that is a probllem

on latest Versions you have to add this permission in the manifest