1、Android O(8.0)通知的改变

NotificationChannel是android8.0新增的特性，如果App的targetSDKVersion>=26，没有设置channel通知渠道的话，就会导致通知无法展示。

Android O 引入了 通知渠道(Notification Channels)，以提供统一的系统来帮助用户管理通知，如果是针对 android O 为目标平台时，必须实现一个或者多个通知渠道，以向用户显示通知。比如聊天软件，为每个聊天组设置一个通知渠道，指定特定声音、灯光等配置。

2、Android Channel通知的兼容支配

创建NotificationChannel

创建NotificationChannel对象，指定Channel的id、name和通知的重要程度

使用NotificationMannager的createNotificationChannel方法来添加Channel。

private NotificationManager getNotificationManager() {

if (mNotificationManager == null) {

mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

}

return mNotificationManager;

}

@NonNull

private NotificationCompat.Builder getNotificationBuilder() {

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

NotificationChannel channel = new NotificationChannel("channel_id", "channel_name",

NotificationManager.IMPORTANCE_DEFAULT);

//是否绕过请勿打扰模式

channel.canBypassDnd();

//闪光灯

channel.enableLights(true);

//锁屏显示通知

channel.setLockscreenVisibility(VISIBILITY_SECRET);

//闪关灯的灯光颜色

channel.setLightColor(Color.RED);

//桌面launcher的消息角标

channel.canShowBadge();

//是否允许震动

channel.enableVibration(true);

//获取系统通知响铃声音的配置

channel.getAudioAttributes();

//获取通知取到组

channel.getGroup();

//设置可绕过 请勿打扰模式

channel.setBypassDnd(true);

//设置震动模式

channel.setVibrationPattern(new long[]{100, 100, 200});

//是否会有灯光

channel.shouldShowLights();

getNotificationManager().createNotificationChannel(channel);

}

NotificationCompat.Builder notification = new NotificationCompat.Builder(this, "channel_id");

notification.setContentTitle("新消息来了");

notification.setContentText("周末到了，不用上班了");

notification.setSmallIcon(R.mipmap.ic_launcher);

notification.setAutoCancel(true);

return notification;

}

设置通知重要性级别

该级别必须要在 NotificationChannel 的构造函数中指定，总共要五个级别；范围是从 NotificationManager.IMPORTANCE_NONE(0) ~ NotificationManager.IMPORTANCE_HIGH(4)

，如果要支持 Android 7.1(API 25)及以下的设备，还得调用NotificationCompat 的 setPriority 方法来设置，如下所示

builder.setPriority(NotificationCompat.PRIORITY_DEFAULT);

Android 8.0 及以上是使用NotificationManager.IMPORTANCE_，Android 7.1 及以下是使用NotificationCompat.PRIORITY_它们都是定义的常量；下面我们以表格的形式更好的展示出来。

用户通知级别

Android8.0及以上

Android7.0及以下

紧急级别(发出通知声音并显示为提示通知)

IMPORTANCE_HIGH

PRIORITY_HIGH或者PRIORITY_MAX

高级别(发出通知声音并且通知栏有通知)

IMPORTANCE_DEFAULT

PRIORITY_DEFAULT

中等级别(没有通知声音但通知栏有通知)

IMPORTANCE_LOW

PRIORITY_LOW

低级别(没有通知声音也不会出现在状态栏上)

IMPORTANCE_MIN

PRIORITY_MIN

上面这些通知级别用户都是可以在 Channel 设置中更改

3、Android Channel通知的应用与管理(更新、删除)

4、自定义Channel通知栏

private void sendCustomNotification() {

NotificationCompat.Builder builder = getNotificationBuilder();

RemoteViews remoteViews = new RemoteViews(getPackageName(), R.layout.layout_custom_notifition);

remoteViews.setTextViewText(R.id.notification_title, "custom_title");

remoteViews.setTextViewText(R.id.notification_content, "custom_content");

Intent intent = new Intent(this, MainActivity.class);

PendingIntent pendingIntent = PendingIntent.getActivity(this, -1,

intent, PendingIntent.FLAG_UPDATE_CURRENT);

remoteViews.setOnClickPendingIntent(R.id.turn_next, pendingIntent);

builder.setCustomContentView(remoteViews);

getNotificationManager().notify(3, builder.build());

}

android:layout_width="match_parent"

android:layout_height="match_parent">

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:orientation="vertical">

android:id="@+id/notification_title"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="通知栏标题"

android:textSize="24sp"/>

android:id="@+id/notification_content"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="通知栏内容"/>

android:id="@+id/turn_next"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentRight="true"

android:text="跳转"/>

5、封装的代码

public class NotificationUtils extends ContextWrapper {

public static final String CHANNEL_ID = "default";

private static final String CHANNEL_NAME = "Default Channel";

private static final String CHANNEL_DESCRIPTION = "this is default channel!";

private NotificationManager mManager;

public NotificationUtils(Context base) {

super(base);

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

createNotificationChannel();

}

}

@TargetApi(Build.VERSION_CODES.O)

private void createNotificationChannel() {

NotificationChannel channel = new NotificationChannel(CHANNEL_ID, CHANNEL_NAME, NotificationManager.IMPORTANCE_DEFAULT);

//是否绕过请勿打扰模式

channel.canBypassDnd();

//闪光灯

channel.enableLights(true);

//锁屏显示通知

channel.setLockscreenVisibility(VISIBILITY_SECRET);

//闪关灯的灯光颜色

channel.setLightColor(Color.RED);

//桌面launcher的消息角标

channel.canShowBadge();

//是否允许震动

channel.enableVibration(true);

//获取系统通知响铃声音的配置

channel.getAudioAttributes();

//获取通知取到组

channel.getGroup();

//设置可绕过 请勿打扰模式

channel.setBypassDnd(true);

//设置震动模式

channel.setVibrationPattern(new long[]{100, 100, 200});

//是否会有灯光

channel.shouldShowLights();

getManager().createNotificationChannel(channel);

}

private NotificationManager getManager() {

if (mManager == null) {

mManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

}

return mManager;

}

/**

* 发送通知

*/

public void sendNotification(String title, String content) {

NotificationCompat.Builder builder = getNotification(title, content);

getManager().notify(1, builder.build());

}

private NotificationCompat.Builder getNotification(String title, String content) {

NotificationCompat.Builder builder = null;

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

builder = new NotificationCompat.Builder(getApplicationContext(), CHANNEL_ID);

} else {

builder = new NotificationCompat.Builder(getApplicationContext());

builder.setPriority(PRIORITY_DEFAULT);

}

//标题

builder.setContentTitle(title);

//文本内容

builder.setContentText(content);

//小图标

builder.setSmallIcon(R.mipmap.ic_launcher);

//设置点击信息后自动清除通知

builder.setAutoCancel(true);

return builder;

}

/**

* 发送通知

*/

public void sendNotification(int notifyId, String title, String content) {

NotificationCompat.Builder builder = getNotification(title, content);

getManager().notify(notifyId, builder.build());

}

/**

* 发送带有进度的通知

*/

public void sendNotificationProgress(String title, String content, int progress, PendingIntent intent) {

NotificationCompat.Builder builder = getNotificationProgress(title, content, progress, intent);

getManager().notify(0, builder.build());

}

/**

* 获取带有进度的Notification

*/

private NotificationCompat.Builder getNotificationProgress(String title, String content,

int progress, PendingIntent intent) {

NotificationCompat.Builder builder = null;

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

builder = new NotificationCompat.Builder(getApplicationContext(), CHANNEL_ID);

} else {

builder = new NotificationCompat.Builder(getApplicationContext());

builder.setPriority(PRIORITY_DEFAULT);

}

//标题

builder.setContentTitle(title);

//文本内容

builder.setContentText(content);

//小图标

builder.setSmallIcon(R.mipmap.ic_launcher);

//设置大图标，未设置时使用小图标代替，拉下通知栏显示的那个图标

//设置大图片 BitmpFactory.decodeResource(Resource res,int id) 根据给定的资源Id解析成位图

builder.setLargeIcon(BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher));

if (progress > 0 && progress < 100) {

//一种是有进度刻度的(false),一种是循环流动的(true)

//设置为false，表示刻度，设置为true，表示流动

builder.setProgress(100, progress, false);

} else {

//0,0,false,可以将进度条隐藏

builder.setProgress(0, 0, false);

builder.setContentText("下载完成");

}

//设置点击信息后自动清除通知

builder.setAutoCancel(true);

//通知的时间

builder.setWhen(System.currentTimeMillis());

//设置点击信息后的跳转(意图)

builder.setContentIntent(intent);

return builder;

}

}