Android打开一个下载的文件

Question

我正在编写一个代码，允许从服务器下载应用程序并自动打开它，但是在代码的最后一步调用Intent（安装）后面临异常

例外：

  

android.content.ActivityNotFoundException：找不到处理Intent的活动{act = android.intent.action.VIEW dat = file：/// file：/storage/emulated/0/Download/application.apk typ = application / apk}

请知道有问题的文件是一个名为application.apk的应用程序，我想在下载完成后直接打开安装页面。以下是代码：

    private void download(String url) {
        DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
        request.allowScanningByMediaScanner();
        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED); //Notify client once download is completed!
        final String filename= URLUtil.guessFileName(url, null, null);
        final String file_extension = filename.replace("bin","apk");
        request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, file_extension);
      final  DownloadManager dm = (DownloadManager)getSystemService(DOWNLOAD_SERVICE);
       final Long enq=  dm.enqueue(request);
        Toast.makeText(getApplicationContext(), "Downloading File", //To notify the Client that the file is being downloaded
                Toast.LENGTH_LONG).show();
/// OPEN File
        BroadcastReceiver receiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                String action = intent.getAction();
                if (DownloadManager.ACTION_DOWNLOAD_COMPLETE.equals(action)) {
                    long downloadId = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, 0);
                    DownloadManager.Query query = new DownloadManager.Query();
                    query.setFilterById(enq);
                    Cursor c = dm.query(query);
                    if (c.moveToFirst()) {
                        int columnIndex = c.getColumnIndex(DownloadManager.COLUMN_STATUS);
                        if (DownloadManager.STATUS_SUCCESSFUL == c.getInt(columnIndex)) {
                            String uriString = c.getString(c.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI));
                            //TODO : Use this local uri and launch intent to open file
                            Intent install = new Intent(Intent.ACTION_VIEW);
                            install.setDataAndType(Uri.fromFile(new File(uriString)), "application/apk");
                            webview_java.this.startActivity(install);
                        }
                    }
                }
            }
        };
        registerReceiver(receiver, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));
    }

我也尝试过startActivity而不是调用webview_java.this.startActivity但它会抛出同样的错误