本文使用DownloadManager下载，包含下载安装全过程。

1.下载

通过DownloadManager下载到安装包目录下/files/Download：

public void downloadApk(String url, String appname) {

    DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));

    request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI); //设置在什么网络情况下进行下载 默认所有的 //

    request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE); //设置通知栏

    request.setTitle(appname);

    request.setDescription(appname + "正在下载");

    request.setAllowedOverRoaming(false);

    request.setDestinationInExternalFilesDir(App.me(), Environment.DIRECTORY_DOWNLOADS, appname + ".apk");

   DownloadManager downManager = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);

    Long id = downManager.enqueue(request);//下载任务的id 建议存储用来查询任务

}

2.下载完成接收

定义广播接收器：

public class DownLoadCompleteReceiver extends BroadcastReceiver {

        @Override

        public void onReceive(Context context, Intent intent) {

            if (intent.getAction().equals(DownloadManager.ACTION_DOWNLOAD_COMPLETE)) {

                long id = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1);

                queryDownTask(DownloadManager.STATUS_SUCCESSFUL, id);//查询任务

            } else if (intent.getAction().equals(DownloadManager.ACTION_NOTIFICATION_CLICKED)) {//通知栏点击

            }

        }

    }

广播接收器注册：

我采用的动态注册，记得unRegisterReceiver(receiver)取消注册哦~

IntentFilter filter =new IntentFilter();

filter.addAction(DownloadManager.ACTION_NOTIFICATION_CLICKED);

filter.addAction(DownloadManager.ACTION_DOWNLOAD_COMPLETE);

context.registerReceiver(downLoadCompleteReceiver, filter);

查询下载任务：

private void queryDownTask(int status, long id) {

        DownloadManager.Query query = new DownloadManager.Query();

        query.setFilterByStatus(status);

        query.setFilterById(id);

        Cursor cursor = downManager.query(query);

        while (cursor.moveToNext()) {

            String downId = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_ID));

            String title = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_TITLE));

            String address = "";

            //注意：这样7.0以上取出来的是file:///开头

            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {

                address = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI));

            } else {

                address = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_FILENAME));

            }

            String statuss = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_STATUS));

            String size = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_BYTES_DOWNLOADED_SO_FAR));

            String sizeTotal = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_TOTAL_SIZE_BYTES));

            Map<String, String> map = new HashMap<String, String>();

            map.put("downid", downId);

            map.put("title", title);

            map.put("address", address);

            map.put("status", statuss);

          //开始根据address进行安装----

        }

        cursor.close();

    }

3.安装

在7.0以上的安装需要获取安装未知应用权限，还需要通过FileProvider拿到content:/开始的地址。

（1）打开安装未知来源权限

（2）安装