App版本更新兼容7.0

        最近在做App版本更新这块的功能，以前也做过，为节省时间，提高开发效率，第一反应就是把之前的代码找出来直接用。三下五除二就搞定了，直接打个包给到测试！果然，一切都太顺利了，只见测试胸有成竹的走过来，说道:你这个版本更新有问题，没法安装！心里咯噔一下，怎么可能，我自己都测试OK的！立马反应过来，那估计是系统问题吧，后来确认，人家测试直接用的7.0的手机测试的。唉，好吧，那就改呗！

       1.实现思路：

        思路很简单，先判断是否需要版本更新，需要更新则启动一个服务去下载最新的apk，并注册一个广播监听下载进度，下载完成则安装apk。

       2.代码实现：

（1）启动服务,若是6.0以上需要动态申请权限

 Intent intent=new Intent(this, DownloadApkService.class); intent.putExtra(DownloadApkService.DOWNLOAD_URL,"http://www.huiqu.co/public/download/apk/huiqu.apk"); startService(intent);

（2）在服务中下载

 public int onStartCommand(Intent intent, int flags, int startId) {        String downLoadUrl = intent.getStringExtra(DOWNLOAD_URL);        mReceiver = new ApkInstallReceiver();        registerReceiver(mReceiver, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));        if (DownLoadUtils.getInstance(this).canDownload()){            downloadApk(this,downLoadUrl,"app下载", appName);        }else {            DownLoadUtils.getInstance(this).skipToDownloadManager();        }        return Service.START_NOT_STICKY;    }

（3）下载完安装，这里是重点：

 public class ApkInstallReceiver extends BroadcastReceiver {        @Override        public void onReceive(Context context, Intent intent) {            if (intent.getAction().equals(DownloadManager.ACTION_DOWNLOAD_COMPLETE)) {                long downloadApkId = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1);                installApk(context);                DownloadApkService.this.stopSelf();            }        }        /**         * 安装apk         */        public void installApk(Context context) {            File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + DownloadApkService.DOWNLOADPATH + appName);            if (!file.exists()) {                Log.e(TAG, "file is not exists");                return;            }            Intent intent = new Intent(Intent.ACTION_VIEW);            String type = "application/vnd.android.package-archive";            Uri downloadUri = null;            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {                downloadUri = Uri.fromFile(file);            } else {                intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);                downloadUri = FileProvider.getUriForFile(context, context.getApplicationContext().getPackageName() + ".provider", file);            }            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);            intent.setDataAndType(downloadUri, type);            context.startActivity(intent);        }    }

3.查看AppUpdateDemo