在RecyclerView中的特定位置更新SeekBar [英] Update SeekBar at particular position within a RecyclerView

问题描述

我正在创建一个用于下载歌曲的应用程序.在我的应用程序中，有一个RecyclerView带有歌曲列表，每首歌曲下方都有一个SeekBar，它显示了下载进度.当我按下下载按钮时，它可以正常工作，但是会更新错误的SeekBar.我想在特定位置更新特定的SeekBar.这是我的RecyclerView适配器:

I am creating an application for downloading songs. In my application, there is a RecyclerView with a list of songs and with every song there is a SeekBar below that shows the download progress. When I hit the download button, it works fine but it updates the wrong SeekBar. I want to update a particular SeekBar at a particular position. Here is my adapter for the RecyclerView:

@Override
    public SongListAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        itemViewLayout = LayoutInflater.from(parent.getContext()).inflate(R.layout.song_list_single_list, null);
        holder = new ViewHolder(itemViewLayout);
        return holder;
    }

    @Override
    public void onBindViewHolder(SongListAdapter.ViewHolder holder, final int position) {
        mSongListModel = mSongListArray.get(position);
        holder.downloadLink.setText(mSongListModel.getDownloadLink());
        holder.downloadButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new DownloadFileAsync().execute(String.valueOf(position));
            }
        });
    }

    @Override
    public int getItemCount() {
        return mSongListArray.size();
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            System.out.println("Permission: " + permissions[0] + "was " + grantResults[0]);
            //resume tasks needing this permission
            //downloadStreamingAudio();
        }
    }

    public class ViewHolder extends RecyclerView.ViewHolder {

        private TextView downloadLink;
        private SeekBar downloadProgress;
        private TextView downloadButton;

        public ViewHolder(View itemView) {
            super(itemView);
            downloadLink = (TextView) itemView.findViewById(R.id.downloadLink);
            downloadButton = (TextView) itemView.findViewById(R.id.downloadButton);
            downloadProgress = (SeekBar) itemViewLayout.findViewById(R.id.downloadProgress);
        }
    }

    class DownloadFileAsync extends AsyncTask<String, String, String> {
        ProgressDialog pDialog;
        Uri uri;
        String timeStamp;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(c);
            pDialog.setMessage("Downlaoding Audio...");
            pDialog.setCancelable(true);
            pDialog.show();
        }

        @Override
        protected String doInBackground(String... params) {

            try {
                if (isStoragePermissionGranted()) {
                    File root = Environment.getExternalStorageDirectory();

                    File dir = new File(root.getAbsolutePath() + "/AppDownloads/");

                    timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
                    System.out.println("Time Stamp::----" + timeStamp);

                    try {
                        if (dir.exists() == false) {
                            dir.mkdirs();
                        }

                        RootFile = new File(dir, timeStamp + ".mp3");

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

                InputStream input = null;
                OutputStream output = null;
                HttpURLConnection connection = null;
                int count;

                System.out.println("DownloadUrl::::----"+mSongListArray.get(Integer.parseInt(params[0])).getDownloadLink());
                URL url = new URL(mSongListArray.get(Integer.parseInt(params[0])).getDownloadLink());
                connection = (HttpURLConnection) url.openConnection();
                connection.connect();
                // this will be useful so that you can show a tipical 0-100% progress bar
                int lenghtOfFile = connection.getContentLength();

                // downlod the file
                input = new BufferedInputStream(url.openStream());
                output = new FileOutputStream(RootFile);

                byte data[] = new byte[1024];

                long total = 0;

                while ((count = input.read(data)) != -1) {
                    total += count;
                    // publishing the progress....
                    //publishProgress((int)(total*100/lenghtOfFile));
                    updateDownloadProgress((int) (total * 100 / lenghtOfFile));
                    output.write(data, 0, count);
                }

                output.flush();
                output.close();
                input.close();

            } catch (Exception e)

            {

                Log.d("Error....", e.toString());
            }

            return null;
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
            if (pDialog.isShowing())

                pDialog.dismiss();

            Toast.makeText(c, "Download Complete", Toast.LENGTH_LONG).show();
        }
    }

    public boolean isStoragePermissionGranted() {
        if (Build.VERSION.SDK_INT >= 23) {
            if (c.checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
                    == PackageManager.PERMISSION_GRANTED) {
                System.out.println("Permission is granted");
                return true;
            } else {

                System.out.println("Permission is revoked");
                ActivityCompat.requestPermissions((Activity) c, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
                return false;
            }
        } else {
            System.out.println("Permission is granted");
            return true;
        }
    }

    private void updateDownloadProgress(int progress) {
        holder.downloadProgress.setProgress(progress);

    }

这是我的RecyclerView的布局文件:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    android:padding="10dp">

    <LinearLayout
        android:id="@+id/LinearLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <TextView
            android:id="@+id/downloadLink"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:padding="10dp" />

        <TextView
            android:id="@+id/downloadButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/custom_button"
            android:text="DOWNLOAD"
            android:textSize="15sp" />

        <TextView
            android:id="@+id/playButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:background="@drawable/custom_button"
            android:text="PLAY"
            android:textSize="15sp"
            android:visibility="gone" />
    </LinearLayout>

    <SeekBar
        android:id="@+id/downloadProgress"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/LinearLayout"
        android:layout_marginTop="10dp" />
</RelativeLayout>

关于如何实现这一目标的任何建议?

Any suggestions on how to achieve this?

推荐答案

您的程序是紧密耦合的.我建议您将程序分为3个阶段. 然后在onProgressUpdated

Your program is tightly-coupled. I recommend you to split program into 3 peaces. And Call notifyItemChanged at onProgressUpdated

下面的代码是示例.

RecyclerView.Adapter像这样:

RecyclerView.Adapter like this:

public class SongListAdapter extends RecyclerView.Adapter<SongListAdapter.ViewHolder> {
    ...

    private final Listener mListener;
    private final Map<Integer, Integer> progressMap = new HashMap<>();

    ...

    interface Listener {
        void onClickDownload(int position, SongListModel songListModel);
    }

    public SongListAdapter(Listener listener) {
        mListener = listener;
    }

    @Override
    public void onBindViewHolder(SongListAdapter.ViewHolder holder, final int position) {
        ...
        int progress = progressMap.containsKey(position) ? progressMap.get(position) : 0;
        holder.downloadProgress.setProgress(progress);
        holder.downloadButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SongListModel songListModel = mSongListArray.get(position);
                mListener.onClickDownload(position, songListModel);
            }
        });
    }
    ...

    public void setProgress(int position, int progress) {
        progressMap.put(position, progress);
    }
    ...
}

像这样的DownloadFileAsync:

DownloadFileAsync like this:

public class DownloadFileAsync extends AsyncTask<String, String, String> {

    ...
    private final Callback mCallback;
    private final int mPosition;
    private final SongListModel mSongListModel;

    interface Callback {
        void onDownloadStarting();
        void onProgressUpdated(int progress, int position, SongListModel songListModel);
        void onDownloadCompleted();
    }

    public DownloadFileAsync(Callback callback, int position, SongListModel songListModel) {
        mCallback = callback;
        mPosition = position;
        mSongListModel = songListModel;
    }

    @Override
    protected void onPreExecute() {
        mCallback.onDownloadStarting();
    }

    @Override
    protected String doInBackground(String... params) {
        try {
            ...
            while ((count = input.read(data)) != -1) {
                ...
                mCallback.onProgressUpdated((int) (total * 100 / lenghtOfFile), mPosition, mSongListModel);
                ...
                if (isCancelled()) {
                    break;
                }
            }
            ...
        }
        return null;
    }

    ...

    @Override
    protected void onPostExecute(String s) {
        mCallback.onDownloadCompleted(s);
    }
}

这样的活动:

public class MainActivity extends AppCompatActivity
        implements SongListAdapter.Listener, DownloadFileAsync.Callback {
    ...

    private RecyclerView mRecyclerView;
    private SongListAdapter mAdapter;
    private DownloadFileAsync mDownloadFileAsync;
    private ProgressDialog pDialog;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ...
        mRecyclerView = (RecyclerView)findViewById(...);
        mAdapter = new SongListAdapter(this);
        mRecyclerView.setAdapter(adapter);
        ...
    }

    @Override
    public void onClickDownload(int position, SongListModel songListModel) {
        if (mDownloadFileAsync != null) {
            //TODO currentry downloading. Insert error handing.
            return;
        }

        mDownloadFileAsync = new DownloadFileAsync(this, position, songListModel);
        mDownloadFileAsync.execute();
    }


    @Override
    public void onDownloadStarting() {
        pDialog = new ProgressDialog(this);
        pDialog.setMessage("Downlaoding Audio...");
        pDialog.setCancelable(true);
        pDialog.show();
    }

    @Override
    public void onProgressUpdated(int progress, int position, SongListModel songListModel) {
        mAdapter.setProgress(position, progress);

        SongListAdapter.ViewHolder holder = mRecyclerView.findViewHolderForAdapterPosition(position);
        if (holder != null) {
            holder.downloadProgress.setProgress(progress);
        }
    }

    @Override
    public void onDownloadCompleted(String s) {
        mDownloadFileAsync = null;
        if (pDialog.isShowing()) {
            pDialog.dismiss();
        }
        Toast.makeText(this, "Download Complete", Toast.LENGTH_LONG).show();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();

        // If you want to stop downloading when activity is closing, call cancel method.
        if (mDownloadFileAsync != null) {
            mDownloadFileAsync.cancel(true);
        }
    }

    ...
}

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