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Android 进价5_自定义广播 通过广播更新ListView的适配器 下载管理

  1、在处理下载管理时,服务在后台运行,下载完成后要更新listview列表的按钮,将“下载”改成“打开”这样一个功能。

  在Activity里面写一个静态内部类,继承广播。其中属性text_button的值就是按钮显示的文字。通过mAdapter.notifyDataSetChanged()更新列表数据显示。

    public static class DownloadFinishReceiver extends BroadcastReceiver{        public static final String DOWNLOAD_RECEIVER="com.DownloadFinishReceiver";                @Override        public void onReceive(Context context, Intent intent) {            try {                if (intent.getAction().equals(DOWNLOAD_RECEIVER)) {                    //传递的下载地址                    String url = intent.getStringExtra("url");                    for(Apply apply : mApplies) {                        if (apply.getDownload_backup().equals(url)) {                            apply.setText_button("打开");                        }                    }                    mAdapter.notifyDataSetChanged();                }            } catch (Exception e) {                e.printStackTrace();            }        }    }

  2、在后台服务service里面注册和销毁广播

    private DownloadFinishReceiver finishReceiver;    public void onCreate() {        System.out.println("创建服务");        IntentFilter intentFilter = new IntentFilter(DownloadFinishReceiver.DOWNLOAD_RECEIVER);        finishReceiver =  new DownloadFinishReceiver();        registerReceiver(finishReceiver, intentFilter);        super.onCreate();    }    public void onDestroy() {        unregisterReceiver(finishReceiver);        super.onDestroy();    }

  3、一旦下载完成,就发送广播。

Intent intent = new Intent(DownloadFinishReceiver.DOWNLOAD_RECEIVER);intent.putExtra("url", "http://www.baidu.com/pic/qqq.png");sendBroadcast(intent);

 

Android 进价5_自定义广播 通过广播更新ListView的适配器 下载管理