java - 如何循环ArrayList并将每个值发送到下载管理器？

Question

我试图将 for 循环内的 ArrayList(VideoUrlArrayList) 值发送到 Android 下载管理器，但我不断收到以下错误:

error: incompatible types: String cannot be converted to Uri

并指向这一行:

DownloadManager.Request request = new DownloadManager.Request(VideoUrlArrayList.get(i));
fileName = VideoUrlArrayList.get(i).substring(VideoUrlArrayList.get(i).lastIndexOf("/"));

如果我删除将 URL 发送到下载管理器的代码部分，Toast 将正确显示 arrayList(VideoUrlArrayList) 值!

你们能帮我解决这个问题并成功地将我的ArrayList的值发送到下载管理器吗？(此外，我想使用VideoUrlArrayList中存储的url中的原始文件名)。谢谢

MainAcitivity.java:

public class MainActivity extends AppCompatActivity {

    private DownloadManager downloadManager;
    private long refid;
    private String fileName;
    ArrayList<Long> list = new ArrayList<>();
    ArrayList<String> VideoUrlArrayList =new ArrayList<String>();


@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        downloadManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);

        registerReceiver(onComplete,
                new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));



        TextView btnMultiple = (TextView) findViewById(R.id.multiple);


        if(!isStoragePermissionGranted())
        {


        }




btnMultiple.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {



                list.clear();

                EditText editText1 = (EditText) findViewById(R.id.editText);
                String linesArray[] = editText1.getText().toString().split("\n");



                for (int i = 0; i < linesArray.length; i++) {
                    String currLine = linesArray[i];

                    VideoUrlArrayList.add(currLine);

                }


                for (int i = 0; i < VideoUrlArrayList.size(); i++) {


                    //Toast.makeText(getApplicationContext(), "Array Text: " + VideoUrlArrayList.get(i), Toast.LENGTH_LONG).show();

                    DownloadManager.Request request = new DownloadManager.Request(VideoUrlArrayList.get(i));
                    fileName = VideoUrlArrayList.get(i).substring(VideoUrlArrayList.get(i).lastIndexOf("/"));

                    request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE);
                    request.setAllowedOverRoaming(false);

                    //Set the title of this download, to be displayed in notifications (if enabled).
                    request.setTitle("Demo Downloading " + fileName);

                    //Set a description of this download, to be displayed in notifications (if enabled)
                    request.setDescription("Downloading " + fileName);

                    //Set whether this download should be displayed in the system's Downloads UI. True by default.
                    request.setVisibleInDownloadsUi(true);

                    //Set the local destination for the downloaded file to a path within the public external storage directory (as returned by getExternalStoragePublicDirectory(String)).
                    request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, fileName);

                    refid = downloadManager.enqueue(request);


                    Log.e("OUTNM", "" + refid);

                    list.add(refid);


                }




            }
        });

                   //the rest of code after this

}

Answer 1

制作这一行:

DownloadManager.Request request = new DownloadManager.Request(VideoUrlArrayList.get(i));

至:

DownloadManager.Request request = new DownloadManager.Request(Uri.parse(VideoUrlArrayList.get(i)));

DoesnloadManager.Request() 接受 Uri 而不是字符串。所以需要将其解析为Uri。