android2.3 api demo 学习系列（21）--App/Notification/Incoming Message

现在我们开始学习android的Status Bar Notifications相关内容

1、首先我们来实现一个Notification：在status bar添加一个图片和信息，并让手机震动。用户打开status bar看到更详细的信息，点击该Notification打开一个activity

首先我们来看实现代码：

 protected void showNotification() {        // look up the notification manager service        NotificationManager nm = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);        // The details of our fake message        CharSequence from = "angie";        CharSequence message = "今天加班记得订饭啊。。。";        // The PendingIntent to launch our activity if the user selects this notification        PendingIntent contentIntent = PendingIntent.getActivity(this, 0,                new Intent(this, IncomingMessageView.class), 0);        // The ticker text, this uses a formatted string so our message could be localized        String tickerText = getString(R.string.app_notification_incomingmessage_view_msg1, message);        // construct the Notification object.        Notification notif = new Notification(R.drawable.main, tickerText,                System.currentTimeMillis());        // Set the info for the views that show in the notification panel.        notif.setLatestEventInfo(this, from, message, contentIntent);        // after a 100ms delay, vibrate for 250ms, pause for 100 ms and        // then vibrate for 500ms.        notif.vibrate = new long[] { 100, 250, 100, 500};        // Note that we use R.layout.incoming_message_panel as the ID for        // the notification.  It could be any integer you want, but we use        // the convention of using a resource id for a string related to        // the notification.  It will always be a unique number within your        // application.        nm.notify(R.string.app_notification_incomingmessage_view_msg1, notif);    }

apidemo里面有详细的注释说明，能很轻松的理解代码的意图。

我们来看下效果图：

相关知识：

1、sdk中关于notification的说明

我们可以使用activity和service来创建一个notification，由于activity可以和用户交互，一般我们更多的是service来使用notification提醒用户。

我们通过Notification的实例来配置notification的图片，信息，intent以及一些其他的附加信息。android的系统是使用NotificationManager来执行和管理Notification，我们不能直接的实例化NotificationManager，必须通过getSystemService()来获取它的引用。将我们得Notification通过notify（）传递进去。下面我们来看下创建一个notification的步骤

1)获得NotificationManager引用:

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

2)实例化 Notification:

int icon = R.drawable.notification_icon;CharSequence tickerText = "Hello";long when = System.currentTimeMillis();Notification notification = new Notification(icon, tickerText, when);

3) 定义notification的 message 和PendingIntent:

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)将notification递交给NotificationManager

private static final int HELLO_ID = 1;mNotificationManager.notify(HELLO_ID, notification);

2、管理notification 我们通过 NotificationManager.

notify(int, Notification)交付我们得notification给NotificationManager。全第一个参数为notification的唯一标示，第二个参数为notification对象。我们可以通过第一个参数来修改删除notification。

3、修改更新notification。通过再次调用setLateEventInfo方法可以修改除了上下文中得标题文字外的所有notification属性。修改后再次notify（）就ok 4、自定义notification的layout

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/layout"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:padding="10dp" >    <ImageView android:id="@+id/image"        android:layout_width="wrap_content"        android:layout_height="fill_parent"        android:layout_alignParentLeft="true"        android:layout_marginRight="10dp" />    <TextView android:id="@+id/title"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_toRightOf="@id/image"        style="@style/NotificationTitle" />    <TextView android:id="@+id/text"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_toRightOf="@id/image"        android:layout_below="@id/title"        style="@style/NotificationText" /></RelativeLayout>

我们注意到textview的style属性，在版本2.3之前我们可以这么定义

<?xml version="1.0" encoding="utf-8"?><resources>    <style name="NotificationText">      <item name="android:textColor">?android:attr/textColorPrimary</item>    </style>    <style name="NotificationTitle">      <item name="android:textColor">?android:attr/textColorPrimary</item>      <item name="android:textStyle">bold</item>    </style>    <!-- If you want a slightly different color for some text,         consider using ?android:attr/textColorSecondary --></resources>

2.3之后：

<?xml version="1.0" encoding="utf-8"?><resources>    <style name="NotificationText" parent="android:TextAppearance.StatusBar.EventContent" />    <style name="NotificationTitle" parent="android:TextAppearance.StatusBar.EventContent.Title" /></resources>

代码中加载自定义样式

RemoteViews contentView = new RemoteViews(getPackageName(), R.layout.custom_notification_layout);contentView.setImageViewResource(R.id.image, R.drawable.notification_image);contentView.setTextViewText(R.id.title, "Custom notification");contentView.setTextViewText(R.id.text, "This is a custom layout");notification.contentView = contentView;

自定义notification中无需再调用setLatestEventInfo

Intent notificationIntent = new Intent(this, MyClass.class);PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0);notification.contentIntent = contentIntent;mNotificationManager.notify(CUSTOM_VIEW_ID, notification);

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