Notification状态栏通知
1建造者模式构建通知类：Notification.Builder
2通知管理器(用于发出通知)：NotificationManager
3通知通道(API 26新增，用户可以选择性屏蔽通知)：NotificationChannel
4通知动作(用户点击滑动通知等)：PaddingIntent
发送通知的步骤
1】获取NotificationManager
2】创建Notification
3】 给Notification 设置参数
4 】使用NotificationManager 发送通知
Android 7.0 ****新内容
Notification.Builder.serPriority:设置通知优先级 Notification.Builder.setStyle:设置通知扩展布局 MessagingStyle:快速回复
Android 8.0 ****新内容
NotificationChannel：用户可以自定义通知的显示，以及关闭某个通知的提示音震动等，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。
重点参链接：
https://www.jianshu.com/p/fa08c846a3de
https://www.jianshu.com/p/bdc132bdb0fa
坑1：手机不展示通知栏
查看是否添加对android 8.0手机的适配（对notification.builder设置channelID）
// 兼容 API 26，Android 8.0
if (Build.VERSION.*SDK_INT *>= Build.VERSION_CODES.*O*){
// 第三个参数表示通知的重要程度，默认则只在通知栏闪烁一下
NotificationChannel notificationChannel = new NotificationChannel("TestId", "TestIdName", NotificationManager.*IMPORTANCE_DEFAULT*);
// 注册通道，注册后除非卸载再安装否则不改变
notificationManager2.createNotificationChannel(notificationChannel);
builder2.setChannelId("TestId");
}
坑2：发送多条消息时，消息数总有一条，且只展示最后一条
发送消息方法：manager.notify(int id,Notification nofi) 中的id是一固定值，应该是变动（比如i++形式）
notificationManager1.notify(a,builder1.build()); a++;
坑3：部分手机（如小米）发送大于等于3条通知后，消息被折叠，并且消息的图标和格式等都无效了。--Android 7.0以上的版本
//小米手机超过3条消息会被合并
if (Build.VERSION.*SDK_INT *>= Build.VERSION_CODES.*KITKAT_WATCH*) {
builder1.setGroupSummary(false);
builder1.setGroup("group"); }
坑4：NotificationCompat.Builder(一个参数)已经弃用，需要换成（两个参数的）
final NotificationCompat.Builder builder3=new NotificationCompat.Builder(this,"Test ");
三种Notification
λ 普通Notification
λ 折叠Notification
是自定义视图的Notification，用来显示长文本和一些自定义布局的场景（比如音乐播放器的视图）要使用RemoteView创建自定义视图。
关键代码：builder.build() 之前执行
RemoteViews remoteViews=new RemoteViews(getPackageName(),R.layout.notification_folded);final Notification notification2=builder2.build();notification2.bigContentView=remoteViews;
λ 悬挂式Notification/横幅式Notification
前两种通知只有在下拉通知栏的时候才会展示，不会直接显示在屏幕上方（但是现在大多手机厂商支持通过开关对以上两种通知进行顶部悬浮展示）
关键是：对builder 设置 setFullScreenIntent()
builder3.setFullScreenIntent(pendingIntent3,true);
/////////////////////////////////
/****普通通知**///获取状态通知栏管理
final NotificationManager notificationManager1=(NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE) ;
final Notification.Builder builder1=new Notification.Builder(this);
Intent intent=new Intent(Intent.ACTION_VIEW, Uri.parse("http://baidu.com"));
PendingIntent pendingIntent=PendingIntent.getActivity(this,0,intent,0);
//为builder添加属性
builder1.setContentIntent(pendingIntent);
builder1.setSmallIcon(R.drawable.come_111_se_icon);
builder1.setLargeIcon(BitmapFactory.decodeResource(getResources(),R.drawable.come_112_se_icon));
builder1.setAutoCancel(true);builder1.setContentTitle("普通通知，百度一下");
builder1.setDefaults(Notification.DEFAULT_ALL);
//小米手机超过3条 消息会被合并
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT_WATCH) {
builder1.setGroupSummary(false);
builder1.setGroup("group");
}
// 兼容 API 26，Android 8.0
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
// 第三个参数表示通知的重要程度，默认则只在通知栏闪烁一下
NotificationChannel notificationChannel = new NotificationChannel("TestId", "TestIdName", NotificationManager.IMPORTANCE_DEFAULT);
// 注册通道，注册后除非卸载再安装否则不改变
notificationManager1.createNotificationChannel(notificationChannel);
builder1.setChannelId("TestId");
}
btn1_ordinary.setOnClickListener(new View.OnClickListener() {
@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
@Override public void onClick(View v) {
notificationManager1.notify(a,builder1.build());
a++;
}
});
////////////////////////////////
/****折叠式通知**/
final NotificationManager notificationManager2=(NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE) ;
Notification.Builder builder2=new Notification.Builder(this);
Intent intent2=new Intent(Intent.ACTION_VIEW, Uri.parse("http://baidu.com"));
PendingIntent pendingIntent2=PendingIntent.getActivity(this,0,intent2,0);
builder2.setContentIntent(pendingIntent2)
.setSmallIcon(R.drawable.come_111_se_icon)
.setLargeIcon(BitmapFactory.decodeResource(getResources(),R.drawable.come_112_se_icon))
.setAutoCancel(true)
.setContentTitle("折叠式通知");
// 兼容 API 26，Android 8.0
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
// 第三个参数表示通知的重要程度，默认则只在通知栏闪烁一下
NotificationChannel notificationChannel = new NotificationChannel("TestId", "TestIdName", NotificationManager.IMPORTANCE_DEFAULT);
// 注册通道，注册后除非卸载再安装否则不改变 notificationManager2.createNotificationChannel(notificationChannel);
builder2.setChannelId("TestId");
}
RemoteViews remoteViews=new RemoteViews(getPackageName(),R.layout.notification_folded);
final Notification notification2=builder2.build();
notification2.bigContentView=remoteViews;
btn2_folded.setOnClickListener(new View.OnClickListener() {
@Override public void onClick(View v) {
notificationManager2.notify(0,notification2);
}
});
////////////////////////////////
/****悬挂式通知**/
final NotificationManager notificationManager3=(NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE) ;
//
//final Notification.Builder builder3=new Notification.Builder(this);
final NotificationCompat.Builder builder3=new NotificationCompat.Builder(this,"Test ");
Intent intent3=new Intent();
intent3.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent3.setClass(this,CardViewActivity.class);
PendingIntent pendingIntent3=PendingIntent.getActivity(this,0,intent3,PendingIntent.FLAG_CANCEL_CURRENT);
builder3.setFullScreenIntent(pendingIntent3,true);
builder3.setSmallIcon(R.drawable.come_116_se_icon)
.setLargeIcon(BitmapFactory.decodeResource(getResources(),R.drawable.come_120_se_icon))
.setAutoCancel(true)
.setContentTitle("悬挂式通知")
.setPriority(NotificationManager.IMPORTANCE_DEFAULT);
// 兼容 API 26，Android 8.0
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
// 第三个参数表示通知的重要程度，默认则只在通知栏闪烁一下
NotificationChannel notificationChannel = new NotificationChannel("Test", "TestName", NotificationManager.IMPORTANCE_HIGH);
// 注册通道，注册后除非卸载再安装否则不改变
notificationManager3.createNotificationChannel(notificationChannel);
builder3.setChannelId("Test"); }
btn3_fluter.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
notificationManager3.notify(0,builder3.build());
} });
///////////////////////////////Notification
//获取状态通知栏管理
NotificationManager manager = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);NotificationCompat.Builder builder;
//判断是否是8.0Android.O
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
NotificationChannel chan1 = new NotificationChannel("static","Primary Channel", NotificationManager.IMPORTANCE_HIGH);
manager.createNotificationChannel(chan1);
builder = new NotificationCompat.Builder(MyIntentService.this, "static");} else {
builder = new NotificationCompat.Builder(MyIntentService.this);}
//对builder进行配置
builder.setContentTitle("xxx")
//设置通知栏标题
.setContentText("xxx")
//设置通知栏显示内容
.setPriority(NotificationCompat.PRIORITY_MAX)
//设置通知优先级
.setSmallIcon(R.mipmap.ic_launcher)
.setAutoCancel(true);
//设置这个标志当用户单击面板就可以将通知取消
//绑定intent，点击图标能够进入某activityIntent
mIntent=new Intent(MyIntentService.this, MainActivity.class);
PendingIntent mPendingIntent=PendingIntent.getActivity(MyIntentService.this, 0, mIntent,PendingIntent.FLAG_UPDATE_CURRENT);
builder.setContentIntent(mPendingIntent);
//绑定Notification，发送通知请求
manager.notify(0, builder.build());
///////////////////////////
