亲测有用，原文下载地址：

原文地址：https://blog.csdn.net/weixin_36554045/article/details/79108796

下面是原文：

创建一个广播类

public class UpdataBroadcastReceiver extends BroadcastReceiver {    @SuppressLint("NewApi")    public void onReceive(Context context, Intent intent) {        long myDwonloadID = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1);        SharedPreferences sPreferences = context.getSharedPreferences("downloadcomplete", 0);        long refernece = sPreferences.getLong("refernece", 0);        if (refernece == myDwonloadID) {            String serviceString = Context.DOWNLOAD_SERVICE;            DownloadManager dManager = (DownloadManager) context.getSystemService(serviceString);            Intent install = new Intent(Intent.ACTION_VIEW);            Uri downloadFileUri = dManager.getUriForDownloadedFile(myDwonloadID);            install.setDataAndType(downloadFileUri, "application/vnd.android.package-archive");            install.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);            context.startActivity(install);        }    }}

在AndroidManifest.xml中去注册广播

最后就是我们的下载方法

1.下载APP更新时

private void downloadAPK(String url) {    DownloadManager dManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);    Uri uri = Uri.parse(url);    DownloadManager.Request request = new DownloadManager.Request(uri);    // 设置下载路径和文件名    request.setDestinationInExternalPublicDir("xxx(路径)", "xxx.apk");    request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);    request.setMimeType("application/vnd.android.package-archive");    // 设置为可被媒体扫描器找到    request.allowScanningByMediaScanner();    // 设置为可见和可管理    request.setVisibleInDownloadsUi(true);    long refernece = dManager.enqueue(request);    // 把当前下载的ID保存起来    SharedPreferences sPreferences = getSharedPreferences("downloadcomplete", 0);    sPreferences.edit().putLong("refernece", refernece).commit();}

2.下载其他文件时

private void imageDownload(String downloadUrl) {    DownloadManager dManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);    Uri uri = Uri.parse(downloadUrl);    DownloadManager.Request request = new DownloadManager.Request(uri);    String[] urlname = downloadUrl.split("/");    // 设置下载路径和文件名    request.setDestinationInExternalPublicDir("xxx(路径)", urlname[urlname.length - 1]);    // request.setDescription("DOTA2资料库新版本下载");    request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);    //request.setMimeType("application/vnd.android.package-archive");    // 设置为可被媒体扫描器找到    request.allowScanningByMediaScanner();    // 设置为可见和可管理    request.setVisibleInDownloadsUi(true);    long refernece = dManager.enqueue(request);}