自定义Notification并利用Handler更新Notification

在消息通知的时候,我们经常用到两个控件Notification和Toast。特别是重要的和需要长时间显示的信息,用Notification最合适不过了。他可以在顶部显示一个图标以标示有了新的通知,当我们拉下通知栏的时候,可以看到详细的通知内容。

最典型的应用就是未看短信和未接来电的显示,还有QQ企鹅,我们一看就知道有一个未接来电或者未看短信,正在挂QQ。同样,我们也可以自定义一个Notification来定义我们自己的程序想要传达的信息。

Notification我把他分为两种,一种是默认的显示方式,另一种是自定义的。

默认的Notification设置方式见我的早一篇博文
http://www.liuzhaocn.com//?p=364

在这里我主要介绍自定义Notification的用法,自定义Notification原理很简单,就是把通知区域自己写一个View,在代码里把Notification的contantview设置为我们自定义的view即可。

例如,这里有一个View

XML语言: notification.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<LinearLayout android:id=“@+id/noti_lay”
xmlns:android=“http://schemas.android.com/apk/res/android”
android:layout_width=“wrap_content”
android:layout_height=“fill_parent”
android:orientation=“vertical”
>
    <LinearLayout android:id=“@+id/top_lay”
        xmlns:android=“http://schemas.android.com/apk/res/android”
        android:layout_width=“wrap_content”
        android:layout_height=“wrap_content”
        android:orientation=“horizontal”
        >
        <ImageView android:id=“@+id/down_iv”
            android:layout_width=“30sp”  �
            android:layout_height=“30sp”
            android:src=“@drawable/downnoti”
            />
        <TextView android:id=“@+id/down_tv”
            android:layout_width=“wrap_content”  �
            android:layout_height=“fill_parent”
            android:textSize=“20sp”
            android:textColor=“#000000”
            />
    </LinearLayout>
    <LinearLayout android:id=“@+id/progress_lay”
        xmlns:android=“http://schemas.android.com/apk/res/android”
        android:layout_width=“wrap_content”
        android:layout_height=“fill_parent”
        android:orientation=“horizontal”
        >
        <TextView android:id=“@+id/down_rate”
            android:layout_width=“wrap_content”  �
            android:layout_height=“fill_parent”
            android:textSize=“20sp”
            android:textColor=“#000000”
            />
        <ProgressBar android:id=“@+id/pb”
            android:layout_width=“260dip”
            android:layout_height=“wrap_content”
            style=“?android:attr/progressBarStyleHorizontal”
            android:layout_gravity=“center_vertical”/>
    </LinearLayout>
</LinearLayout>

把他放在layout文件夹下。
这就是在通知区域要显示的东西,显示效果如下:
自定义Notification并利用Handler更新Notification

操作Notification的代码:

Java语言: Codee#17015
public Notification downloadNotification;
public NotificationManager downloadNM;

//……..

/**
                 * 添加顶部下载通知
                 * liuzhao
                 */
                downloadNM = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
                downloadNotification = new Notification(R.drawable.downnoti,apkname+“下载…”,System.currentTimeMillis());
                downloadNotification.contentView = new RemoteViews(getPackageName(),R.layout.notification);
                //设置进度条的最大进度和初始进度
                downloadNotification.contentView.setProgressBar(R.id.pb, 100,0, false);
                //显示下载的包名
                downloadNotification.contentView.setTextViewText(R.id.down_tv, apkname);
                //显示下载的进度
                downloadNotification.contentView.setTextViewText(R.id.down_rate, “0%”);
              �
                Intent notificationIntent = new Intent(tykmAndroid.this,tykmAndroid.class);
                PendingIntent contentIntent = PendingIntent.getActivity(tykmAndroid.this,0,notificationIntent,0);
                downloadNotification.contentIntent = contentIntent;
                //显示通知
                downloadNM.notify(downNotiID, downloadNotification);
              �
                //…….

以上是让通知显示出来,下边要根据下载的进度,改变进度条的进度:
下载进程中的核心代码:

Java语言: 下载进程

InputStream is = conn.getInputStream();
                            FileOutputStream fos = new FileOutputStream(file);
                            byte[] bt = new byte[1024];
                            int i = 0;
                            int progresCount = 0;
                            int times = 0;
                            while ((i = is.read(bt)) > 0) {
                                fos.write(bt, 0, i);
                                tykmAndroid.flagloading=1;
                                firstCat.flagloading=1;
                                long tempFileLength = file.length();
                                if((times == 512)||(tempFileLength == length)){
                                    //更新通知中的进度条
                                    int progress = (int)(tempFileLength*100/length);
                                    if(progresCount<progress){
                                       
                                        progresCount=progress;
                                        System.out.println("progresCount="+progresCount);
                                       
                                        //利用Handler在主线程中更新
                                        Message msg = new Message();
                                        msg.what = 6001;
                                        Bundle b = new Bundle();
                                        b.putInt("progressValue", progresCount);
                                        b.putString("apkName", filename);
                                        msg.setData(b);
                                        tykmAndroid.tykmAndroid_Entity.handler.sendMessage(msg);
                                       
                                    }
                                    times=0;
                                    continue;
                                }
                                times++;
                            }
                            fos.flush();
                            fos.close();
                            is.close();
                            conn.disconnect();

这里没有直接对通知进行更新,而是用了一个handler,让UI线程去更新。
UI线程中的Handler是这样写的:


case 6001://下载的时候更新Notification
                Bundle b = msg.getData();
                //得到进度条的当前值
                int progressCount = b.getInt("progressValue");
                //得到包名
                String apkName = b.getString("apkName");
               
                //下载未完成,显示进度条
                if(progressCount !=100 ){
                    //设置进度条
                    downloadNotification.contentView.setProgressBar(R.id.pb, 100, progressCount, false);
                    //设置百分比
                    downloadNotification.contentView.setTextViewText(R.id.down_rate, ""+progressCount+"%");
                    //更新进度条
                }
                //下载完成,显示下载完成
                else{
                    downloadNotification.contentView.removeAllViews(R.id.progress_lay);
                    PendingIntent contentIntent = PendingIntent.getActivity(tykmAndroid.tykmAndroid_Entity, 0, getIntent(), 0);
                    downloadNotification.setLatestEventInfo(tykmAndroid.tykmAndroid_Entity,apkName,"下载完成",contentIntent);
                }
                downloadNM.notify(downNotiID, downloadNotification);
                break;

这里有一段代码:
在Download线程里面:
if((times == 512)||(tempFileLength == length)){
这是防止频繁地更新通知,而导致系统变慢甚至崩溃。
非常重要。。。。。

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