DownloadManager manager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
    Uri uri = Uri.parse("https://www.netkiller.cn/linux/images/cover.png");
    DownloadManager.Request request = new DownloadManager.Request(uri);
    request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE);
    long reference = manager.enqueue(request);		
		
		

		
fun installApk(apkPath: Uri?) {
    val intent = Intent()
    intent.action = Intent.ACTION_VIEW
    intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK
    intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
    intent.setDataAndType(apkPath, "application/vnd.android.package-archive")
    builder.context.startActivity(intent)
}		
		
		

		

    public void download(String url) {
        try {
            //下载路径，如果路径无效了，可换成你的下载路径
//            String url = "https://www.netkiller.cn/linux/images/cover.png";
            String fileName = "test.jpg";
            if (!url.contains("https")) {
                url = url.replaceFirst("http", "https");
            }
            //创建下载任务,downloadUrl就是下载链接
            DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
            //指定下载路径和下载文件名
//            request.setDestinationInExternalPublicDir(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), url.substring(url.lastIndexOf("/") + 1));
//            request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE);
//            request.setTitle("Image Download");
//            request.setDescription("Image download using DownloadManager.");
//            request.setDestinationInExternalPublicDir(getExternalFilesDir(Environment.DIRECTORY_PICTURES) + "", "sample2.jpg");
            request.setDestinationInExternalPublicDir(Environment.DIRECTORY_PICTURES, fileName);
            request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE);
            request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
            //request.allowScanningByMediaScanner();

            //获取下载管理器
            DownloadManager downloadManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
            //将下载任务加入下载队列，否则不会进行下载
            long reference = downloadManager.enqueue(request);
            broadcast(reference);


        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void broadcast(final long downloadId) {

        // 注册广播监听系统的下载完成事件。
        IntentFilter intentFilter = new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE);
        BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                try {
//                long ID = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1);
                    long id = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, 0);
                    if (id == downloadId) {
                        Toast.makeText(getApplicationContext(), "任务:" + id + " 下载完成!", Toast.LENGTH_LONG).show();
                        Log.d(TAG, "任务:" + id + " 下载完成!");
                    }
                    if (DownloadManager.ACTION_DOWNLOAD_COMPLETE.equals(intent.getAction())) {
                        DownloadManager downloadManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
//                        Uri uri = downloadManager.getUriForDownloadedFile(id);
//                        Log.d(TAG, uri.toString());
                        DownloadManager.Query query = new DownloadManager.Query();
//                    //在广播中取出下载任务的id
                        query.setFilterById(id);
                        Cursor cursor = downloadManager.query(query);
                        if (cursor.moveToFirst()) {

//                        int fileNameIdx = cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_FILENAME);
                            //获取文件下载路径
                            int fileUriIdx = cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI);

//                        String fileName = cursor.getString(fileNameIdx);

                            String fileUri = cursor.getString(fileUriIdx);
                            Log.d(TAG, "fileUri: " + fileUri);


//                        //如果文件名不为空，说明已经存在了，拿到文件名想干嘛都好
                            if (fileUri != null) {
//                            Intent intent = new Intent();
                                intent.setAction("image");
                                intent.putExtra("image", fileUri);
                                context.sendBroadcast(intent);
                            }
                        }
                        cursor.close();
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        };

        registerReceiver(broadcastReceiver, intentFilter);

    }