Question

我要尝试的是成功下载文件后应从文件路径自动打开它，但是现在这里的问题是，当我尝试执行此操作时，我需要从回收者视图适配器类中触发该路径它产生一个异常看一下我的适配器类：在这里，我使用的是带有适配器的类，该适配器将基本上从url下载文件，但是当我尝试激发从下载类打开文件的意图时，它只会出错，这是错误的。

public class Filelistadapter extends RecyclerView.Adapter<Filelistadapter.ProjectViewHolder>{
    private String url;

    private ArrayList<Taskmsg> dataList;


    Context mContext;


    public Filelistadapter(ArrayList<Taskmsg> dataList, Context mContext) {
        this.dataList = dataList;
        this.mContext=mContext;

    }

    @Override
    public ProjectViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
        View view = layoutInflater.inflate(R.layout.file_item, parent, false);
        return new ProjectViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ProjectViewHolder holder, int position) {
        String fname=dataList.get(position).getFilename();
        holder.txtfilename.setText(fname);
        holder.download.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                url="http://pms.cloudester.com/task_doc/"+fname;
                new DownloadFile().execute(url);

            }
        });


    }



    @Override
    public int getItemCount() {

        return dataList.size();

    }

    class ProjectViewHolder extends RecyclerView.ViewHolder {

        TextView txtfilename;
        Button download;
        ProjectViewHolder(View itemView) {
            super(itemView);
            txtfilename = (TextView) itemView.findViewById(R.id.tvfilename);
            download=itemView.findViewById(R.id.actionButton);

        }
    }

    private class DownloadFile extends AsyncTask<String, String, String> {

        private ProgressDialog progressDialog;
        private String fileName;
        private String folder;
        private boolean isDownloaded;

        /**
         * Before starting background thread
         * Show Progress Bar Dialog
         */
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            this.progressDialog = new ProgressDialog(mContext);
            this.progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
            this.progressDialog.setCancelable(false);
            this.progressDialog.show();
        }

        /**
         * Downloading file in background thread
         */
        @Override
        protected String doInBackground(String... f_url) {
            int count;
            try {
                URL url = new URL(f_url[0]);
                URLConnection connection = url.openConnection();
                connection.connect();
                // getting file length
                int lengthOfFile = connection.getContentLength();


                // input stream to read file - with 8k buffer
                InputStream input = new BufferedInputStream(url.openStream(), 8192);

                String timestamp = new SimpleDateFormat("yyyy.MM.dd.HH.mm.ss").format(new Date());

                //Extract file name from URL
                fileName = f_url[0].substring(f_url[0].lastIndexOf('/') + 1, f_url[0].length());

                //Append timestamp to file name
                fileName = timestamp + "_" + fileName;

                //External directory path to save file
                folder = Environment.getExternalStorageDirectory() + File.separator + "pms/";

                //Create androiddeft folder if it does not exist
                File directory = new File(folder);

                if (!directory.exists()) {
                    directory.mkdirs();
                }

                // Output stream to write file
                OutputStream output = new FileOutputStream(folder + fileName);

                byte data[] = new byte[1024];

                long total = 0;

                while ((count = input.read(data)) != -1) {
                    total += count;
                    // publishing the progress....
                    // After this onProgressUpdate will be called
                    publishProgress("" + (int) ((total * 100) / lengthOfFile));


                    // writing data to file
                    output.write(data, 0, count);
                }

                // flushing output
                output.flush();

                // closing streams
                output.close();
                input.close();
                return "Downloaded at: " + folder + fileName;
            } catch (Exception e) {
                Log.e("Error: ", e.getMessage());
            }
            return "Something went wrong";
        }

        /**
         * Updating progress bar
         */
        protected void onProgressUpdate(String... progress) {
            // setting progress percentage
            progressDialog.setProgress(Integer.parseInt(progress[0]));
        }


        @Override
        protected void onPostExecute(String message) {
            // dismiss the dialog after the file was downloaded
            this.progressDialog.dismiss();

            // Display File path after downloading
            Toast.makeText(mContext,
                    message, Toast.LENGTH_LONG).show();
        }
    }
}

Answer 1

您有两个错误

在按钮内部单击此按钮，否则将始终获得上一个位置的名称

字符串fname = dataList.get（position）.getFilename（）;

然后在需要时执行所需的方法更改类型

Intent testIntent = new Intent();
    testIntent.setType("application/pdf");
    testIntent.setAction(Intent.ACTION_VIEW);
    Uri uri = Uri.fromFile(folder+filename);
    testIntent.setDataAndType(uri, "application/pdf");
    startActivity(testIntent);

如何从Recycler View适配器类打开任何类型的文件？

1 个答案: