Android实现Service下载文件，Notification显示下载进度的示例

先放个gif。。最终效果如果：

主要演示了android从服务器下载文件，调用notification显示下载进度，并且在下载完毕以后点击通知会跳转到安装apk的界面，演示是在真实的网络环境中使用真实的url进行演示，来看看代码：

mainactivity代码非常简单，就是启动一个service：

public class mainactivity extends appcompatactivity {
 string download_url="http://shouji.360tpcdn.com/160329/a9037075b8d3aa98fbf6115c54a5b895/com.alensw.picfolder_4722404.apk";

 @override
 protected void oncreate(bundle savedinstancestate) {
  super.oncreate(savedinstancestate);
  setcontentview(r.layout.activity_main);

 }
 public void bt_start_service(view view){
  intent intent=new intent(this,downloadservice.class);
  intent.putextra("download_url",download_url);
  startservice(intent);
 }
}

downloadservice里面，在onstartcommand方法里面是关键代码，调用notifyutil这个工具类的“notify_progress”方法去显示一个通知，与此同时开始下载apk文件，downloadservice代码如下：

public class downloadservice extends service {
 string download_url;
 string savepath= environment.getexternalstoragedirectory()+"/liulan.apk";
 private int requestcode = (int) systemclock.uptimemillis();
 private notifyutil currentnotify;
 file mfile;
 @nullable
 @override
 public ibinder onbind(intent intent) {
  return null;
 }

 @override
 public void oncreate() {
  super.oncreate();


 }

 @override
 public int onstartcommand(intent intent, int flags, int startid) {
  mfile=new file(savepath);
  download_url=intent.getstringextra("download_url");
  log.e("test","执行onstartcommand");
  //设置想要展示的数据内容
  intent intent_noti = new intent();
  intent_noti.setaction(intent.action_view);
  //文件的类型，从tomcat里面找
  intent_noti.setdataandtype(uri.fromfile(mfile), "application/vnd.android.package-archive");
  pendingintent rightpendintent = pendingintent.getactivity(this,
    requestcode, intent_noti, pendingintent.flag_update_current);
  int smallicon = r.drawable.xc_smaillicon;
  string ticker = "正在更新快图浏览";
  //实例化工具类，并且调用接口
  notifyutil notify7 = new notifyutil(this, 7);
  notify7.notify_progress(rightpendintent, smallicon, ticker, "快图浏览升级程序", "正在下载中",
    false, false, false, download_url, savepath, new notifyutil.downloadlistener() {
     @override
     public void onsuccess(file file) {
      mfile=file;
      downloadservice.this.stopself();
     }

     @override
     public void onfailure(throwable t, int errorno, string strmsg) {

     }
    });
  currentnotify = notify7;
  return super.onstartcommand(intent, flags, startid);

 }
}

在调用“notify_progress”方法的时候，已经开始下载文件了，那么下载的代码是什么呢？如下：

public void notify_progress(pendingintent pendingintent, int smallicon,
        string ticker, string title, string content,
        boolean sound, boolean vibrate, boolean lights,
        string download_url, string savepath, final downloadlistener listener) {

  setcompatbuilder(pendingintent, smallicon, ticker, title, content, sound, vibrate, lights);
  /*
   * 因为进度条要实时更新通知栏也就说要不断的发送新的提示，所以这里不建议开启通知声音。
   * 这里是作为范例，给大家讲解下原理。所以发送通知后会听到多次的通知声音。
   */
  finalhttp fh = new finalhttp();
  httphandler<file> httphandler=fh.download(download_url, savepath, new ajaxcallback<file>() {
   @override
   public void onloading(long count, long current) {
    super.onloading(count, current);
    double a=count;
    double b=current;
    double currentpro=(double)((b/a)*100);
    cbuilder.setprogress(100, (int)currentpro, false);
    sent();
   }

   @override
   public void onsuccess(file file) {
    super.onsuccess(file);
    cbuilder.setcontenttext("下载完成").setprogress(0, 0, false);
    sent();
    listener.onsuccess(file);
   }

   @override
   public void onfailure(throwable t, int errorno, string strmsg) {
    super.onfailure(t, errorno, strmsg);
    listener.onfailure(t,errorno,strmsg);
   }

  });


 }

这里用到了

这个jar已经封装好下载的工具类，我们直接拿来用就行。下载成功之后会通过downloadlistener这个接口回调到downloadservice里面，最终运行效果就如最上面那个gif动态图运行效果一样。

项目下载地址：点击下载

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