android - 使用具有特定位置的 'circular progress' 从服务器下载音频文件

Question

我已经使用 websrvice 数据创建了一个音乐应用程序。我从网络服务获取所有数据并将其设置为 ListView ，现在我想下载音频并将其存储在 sdcard 中。

我想点击下载 imageview，我希望 imagview 更改为进度条和文件下载。下载文件后，我希望更改图像，但没有。

我该如何解决这个问题？

public class DownloadTask extends AsyncTask<String, Integer, String> 
{
        Context context;

        private static final int MEGABYTE = 1024 * 1024;
        AudioRecyleviewAdapter.DownloadTask downloadTask;
        String Name;
        ProgressDialog mProgressDialog;
        ProgressBar progressBar;
        ImageView imgdowload;
        int position;

        public DownloadTask(Context context) {
            this.context = context;
        }


        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            // mProgressDialog = new ProgressDialog(context);
            mProgressDialog = new ProgressDialog(context);
            mProgressDialog.setMessage("Downloading....");
            mProgressDialog.setIndeterminate(true);
            mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
            mProgressDialog.setCancelable(false);

            mProgressDialog.show();

            mProgressDialog.setOnCancelListener(new DialogInterface.OnCancelListener() {
                @Override
                public void onCancel(DialogInterface dialog) {

                    String sdcard_path = Environment.getExternalStorageDirectory().getPath();
                    File file = new File(sdcard_path + "/Petli Satsang/" + Name + ".mp3");
                    file.delete();
                    Toast.makeText(context, "Download In Background", Toast.LENGTH_SHORT).show();
                }
            });
        }

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

            String URL = str[0];
            Name = str[1];
            InputStream input = null;
            OutputStream output = null;
            HttpURLConnection connection = null;
            try {
                java.net.URL url = new URL(URL);
                connection = (HttpURLConnection) url.openConnection();
                connection.connect();
                if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
                    return "Server returned HTTP " + connection.getResponseCode()
                            + " " + connection.getResponseMessage();
                }
                int fileLength = connection.getContentLength();
                input = connection.getInputStream();
                String sdcard_path = Environment.getExternalStorageDirectory().getPath();
                File PapersDiractory = new File(sdcard_path + "/Petli Satsang/");
                PapersDiractory.mkdirs();
                File outputFile = new File(PapersDiractory, "" + Name);
                output = new FileOutputStream(outputFile);

                byte data[] = new byte[MEGABYTE];
                long total = 0;
                int count;
                while ((count = input.read(data)) != -1) {
                    if (isCancelled()) {
                        input.close();
                        return null;
                    }
                    total += count;
                    if (fileLength > 0) // only if total length is known
                        publishProgress((int) (total * 100 / fileLength));
                    int progress = (int) (total * 100 / fileLength);
                    Log.d("Progress = ", "" + (int) (total * 100 / fileLength));
                    output.write(data, 0, count);
                }
            } catch (Exception e) {
                return e.toString();
            } finally {
                try {
                    if (output != null)
                        output.close();
                    if (input != null)
                        input.close();
                } catch (IOException ignored) {
                }

                if (connection != null)
                    connection.disconnect();
            }
            return null;
        }

        @Override
        protected void onProgressUpdate(Integer... progress) {
            super.onProgressUpdate(progress);
            // if we get here, length is known, now set indeterminate to false
            mProgressDialog.setIndeterminate(false);
            mProgressDialog.setMax(100);
            mProgressDialog.setProgress(progress[0]);
            //progressBar.setProgress(Integer.parseInt(String.valueOf(progress[0])));

        }

        @Override
        protected void onPostExecute(String result) {
            mProgressDialog.dismiss();
            if (result != null)
                Toast.makeText(context, "Download error: " + result, Toast.LENGTH_LONG).show();
            else {
                int position = 0;
                Toast.makeText(context, "File downloaded", Toast.LENGTH_SHORT).show();
            }
        }
    }

//调用下载图片cilck函数的代码

 holder.download.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                File extStore = Environment.getExternalStorageDirectory();
                final File myFile = new File(extStore.getAbsolutePath() + "/Petli Satsang/" + detail.getTitle() + ".mp3");
                if (!myFile.exists()) {
                    if (isOnline()) {
                        DownloadTask downloadTask = new DownloadTask(context);
                        downloadTask.execute(Constant.ImagePath_audio1 + detail.getPath(), "" + detail.getTitle() + ".mp3");
                    } else {
                        try {
                            AlertDialog alertDialog = new AlertDialog.Builder(context).create();
                            alertDialog.setTitle("Info");
                            alertDialog.setMessage("Internet not available, Cross check your internet connectivity and try again");
                            alertDialog.setIcon(android.R.drawable.ic_dialog_alert);
                            alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog, int which) {
                                    dialog.cancel();
                                }
                            });
                            alertDialog.show();
                        } catch (Exception e) {
                            //Log.d(Constants.TAG, "Show Dialog: " + e.getMessage());
                        }
                    }
                } else {
                    Toast.makeText(context, "File already Exists in " + myFile, Toast.LENGTH_SHORT).show();
                }

Answer 1

在 AsyncTask 中使用 setter getter 或构造函数将您的 View 传递给 AsyncTask

    this.clickedRowView = clickedRowView;
    public DownloadTask(Context context,View clickedRowView) {
        this.context = context;
        this.clickedRowView = clickedRowView;
    }

像在 onclick 中调用你的 DownloadTask

//v comes from onClick method which points to holder.download view.
DownloadTask downloadTask = new DownloadTask(context,v);
v.setVisibility(View.INVISIBLE);//make Image View invisible and display progressbar

((RelativeLayout)v.getParent()).findViewById(R.id.progressBar).setVisibility(View.VISIBLE);// make progressbar to visible

现在你将你的 View 保存到异步任务中，现在你应该在下载成功或失败后更改你的 ImageView

    @Override
    protected void onPostExecute(String result) {
        mProgressDialog.dismiss();
        clickedImageView.setVisibility(View.VISIBLE);
        ((RelativeLayout)v.getParent()).findViewById(R.id.progressBar).setVisibility(View.INVISIBLE);// make progressbar to invisible **EDIT 1**
        if (result != null)
            Toast.makeText(context, "Download error: " + result, Toast.LENGTH_LONG).show();
        else {
            int position = 0;
            Toast.makeText(context, "File downloaded", Toast.LENGTH_SHORT).show();
        }
        if(clickedRowView != null){
             //You can reach your holder view in here! if this is image view just set image with ((ImageView)clickedRowView).setImageBitmap(...); etc..
        }
    }

编辑 1:如果你想让你的 Image View 不可见并使 Progress Bar 可见，你应该将它们放在同一个 ViewGroup 中并将 Visibility 设置为正确的状态。
并像这样更改包含 ImageView 的 xml 文件:

<RelativeLayout 
  android:id="@+id/imageAndProgressContainer"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content">
    <ImageView 
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="visible"/>
    <ProgressBar
        android:id="@+id/progressBar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="invisible"/>
  </RelativeLayout>