Android学习笔记-- Notifying the User
1.Toast 式的Notification
Toast Notification 是一种弹出式提示，它仅仅是自动显示一个消息，并自动消失，它不能接收任何的事件，不可以对其进行中继处理。Toast 可以在Activity 或者 Service中创建。如果在一个Service中创建一个Toast,它会在当前活动中的Activity显示。只有在自定义Toast的情况下才能调用Toast的构造函数来新建一个提示窗口，不是自定义时要用Toast.makeText(context, text, duration)获取一个Toast实例。
//默认的Toast提示
toastNotificationBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Context context = getApplicationContext();
CharSequence text = "Hello toast";
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, text, duration);
// 设置相对位置
toast.setGravity(Gravity.TOP | Gravity.LEFT, 0, 0);
toast.show();
}
});
//自定义的Toast提示
Button customToastNotificationBtn = (Button) findViewById(R.id.customToastNotificationBtn);
customToastNotificationBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
LayoutInflater inflater = getLayoutInflater();
View layout = inflater
.inflate(
R.layout.customer_toast_layout,
(ViewGroup) findViewById(R.layout.customer_toast_layout));
ImageView image = (ImageView) layout.findViewById(R.id.image);
image.setImageResource(R.drawable.icon);
TextView text = (TextView) layout.findViewById(R.id.text);
text.setText("Hello! This is a custom toast!");
Toast toast = new Toast(getApplicationContext());
toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
toast.setDuration(Toast.LENGTH_LONG);
toast.setView(layout);
toast.show();
}
});
2.Status bar 中显示的 Notification如下：
必要的配置：
1)要有一个图标资源
2)要有一个标题和展开消息时的消息内容
3)PendingIntent, 在点击消息内容时，就会激活PendingIntent。
可选的配置：
1)在status bar中显示的内容
2)可播放一段音频文件
3)振动设置
4)LED灯设置
实现步骤：
1)取得NotificationManager的实例
String ns = Context.NOTIFICATION_SERVICE; NotificationManager mNotificationManager = (NotificationManager) getSystemService(ns);
2)初始化Notification
int icon = R.drawable.notification_icon; CharSequence tickerText = "Hello"; long when = System.currentTimeMillis(); Notification notification = new Notification(icon, tickerText, when);
3)定义展开时的内容和Intent
Context context = getApplicationContext(); CharSequence contentTitle = "My notification"; CharSequence contentText = "Hello World!"; Intent notificationIntent = new Intent(this, MyClass.class); PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0); notification.setLatestEventInfo(context, contentTitle, contentText, contentIntent);
4)把消息显示到Status Bar上面
private static final int HELLO_ID = 1; mNotificationManager.notify(HELLO_ID, notification);
最终例子如下：
//默认的提示
barNotification.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
int icon = R.drawable.icon;//icon from resources
CharSequence tickerText = "Hello";//ticker-text
long when = System.currentTimeMillis();//notification time
Context context = getApplicationContext();//application context
CharSequence contentTitle = "My notification";//expanded message title
CharSequence contentText = "Hello World!";//expanded message text
Intent notificationIntent = new Intent(getApplicationContext(),BarNotificationActivity.class);
PendingIntent contentIntent = PendingIntent.getActivity(getApplicationContext(), 0, notificationIntent, 0);
Notification notification = new Notification(icon, tickerText, when);
notification.setLatestEventInfo(context, contentTitle, contentText, contentIntent);
NotificationManager notificationManager = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(HELLO_ID, notification);
}
});
//自定义的提示
barNotificationCustom.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
RemoteViews contentView = new RemoteViews(getPackageName(),R.layout.customer_toast_layout);
contentView.setImageViewResource(R.id.image, R.drawable.icon);
contentView.setTextViewText(R.id.text, "Hello, this message is in a custom expanded view");
Notification notification = new Notification(R.drawable.icon,"Hello",System.currentTimeMillis());
notification.contentView = contentView;
Intent notificationIntent = new Intent(getApplicationContext(),BarNotificationActivity.class);
PendingIntent contentIntent = PendingIntent.getActivity(getApplicationContext(), 0, notificationIntent, 0);
notification.contentIntent = contentIntent;
NotificationManager manager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
manager.notify(CUSTOM_VIEW_ID, notification);
}
});
3. 更新Status bar的提示
可以更新已经存在的notification用来显示最新的内容，这样就比创建一个新的notification实例更好。
由于每个Notifycation都有一个标识号，我们可以通过NotificationManager来获取到它，并调用setLatestEventInfo()来更新提示的内容，然后调用notify() 来触发它。但是对于自定义的 expanded view,用这些方法来更新提示是不起作用的。
5.给提示添加声音
notification.defaults |= Notification.DEFAULT_SOUND;
notification.sound = Uri.parse("file:///sdcard/notification/ringer.mp3");
6.给提示添加振动效果
notification.defaults |= Notification.DEFAULT_VIBRATE;
long[] vibrate = {0,100,200,300};
notification.vibrate = vibrate;
7.添加闪灯效果
notification.defaults |= Notification.DEFAULT_LIGHTS; notification.ledARGB = 0xff00ff00; notification.ledOnMS = 300; notification.ledOffMS = 1000; notification.flags |= Notification.FLAG_SHOW_LIGHTS;
8.其他效果
通过给Notification添加fields和flags,还可以实现更多的效果。这些属性如下：
"FLAG_AUTO_CANCEL" flag , 这个flags field将使Notification在用户选择了该提示之后自动消失。
"FLAG_INSISTENT" flag , 不继重复播放音频直到用户响应。
"FLAG_ONGOING_EVENT" flag
LevelListDrawable that is used for the notification icon. You can animate the icon in the status bar by changing this value to correlate with the drawable's defined in a LevelListDrawable. See the
LevelListDrawable reference for more information.