Question

我在Dropbox帐户中有多个文件。我正在成功下载文件。但是我希望显示进度条的百分比所以当所有文件都被下载时。进度条结束。我正在使用AsyncTask下载文件。这是我的代码。

public void onPreExecute(){

        mDialog = new ProgressDialog(mContext);
        mDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        mDialog.setMax(100);
        mDialog.show();
    }

    public void downloadFiles(String filename){
        Log.i("Item Name",filename);
        File dir = null;
        Boolean isSDPresent = android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);


        if(isSDPresent){

        File sdCard = Environment.getExternalStorageDirectory();
         dir = new File (sdCard.getAbsolutePath() + "/AllSecure");
        if (!dir.exists()) {
            dir.mkdirs();
        }
        }else{

            dir = mContext.getDir("users", Context.MODE_PRIVATE); //Creating an internal dir;
            if(!dir.exists())
            {
                 dir.mkdirs();
            }     

        }

        File file = new File(dir, filename);
        try {
            FileOutputStream mFileOutputStream=new FileOutputStream(file);

            DropboxFileInfo mDropboxFileInxfo=mApi.getFile(PHOTO_DIR + filename, null, mFileOutputStream, null);

            } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            } catch (DropboxException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            }
    }


    protected String doInBackground(String... params) {

         SessionUtil ses = new SessionUtil(mContext);
            AndroidAuthSession session = ses.buildSession();
            mApi = new DropboxAPI<AndroidAuthSession>(session);


        Entry entries = null;

        try {
            System.out.println("mApi is " + mApi);
            entries = mApi.metadata(PHOTO_DIR, 10000, null, true, null);
        } catch (DropboxException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

        for (Entry e : entries.contents) {
            if (!e.isDeleted) {
                //Log.i("Is Folder",String.valueOf(e.isDir));
                downloadFiles(e.fileName());
                 mFileLen = entries.bytes;
                Log.i("Item Name",e.fileName());
            }
        }



       return null;
    }

    protected void onProgressUpdate(Integer... progress) {

    }

    @Override
    protected void onPostExecute(String result) {
        mDialog.dismiss();



    }

Answer 1

在Dropbox API中有一个名为ProgressListener的有用的抽象类，我像这样使用它

DBApi.getFile(dropPath, null, outputStream, new ProgressListener(){
                    @Override
                    public long progressInterval() {
                        return 500;
                    }
                    @Override
                    public void onProgress(long arg0, long arg1) {
                        int totalSize=(int) arg1;
                        int downloadedSize=(int) arg0;
                        //Here you can interact with progressbar
                    }
                });

Answer 2

有很多样品可供选择。请查看此 tutorial

enter image description here

Answer 3

您可以使用进度条。代码可能如下所示：

private ProgressBar mProgressBar;
public void onPreExecute(){
    mProgressBar.setVisibility(ProgressBar.VISIBLE);
    }

    public void downloadFiles(String filename){
        Log.i("Item Name",filename);
        File dir = null;
        Boolean isSDPresent = android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);


        if(isSDPresent){

        File sdCard = Environment.getExternalStorageDirectory();
         dir = new File (sdCard.getAbsolutePath() + "/AllSecure");
        if (!dir.exists()) {
            dir.mkdirs();
        }
        }else{

            dir = mContext.getDir("users", Context.MODE_PRIVATE); //Creating an internal dir;
            if(!dir.exists())
            {
                 dir.mkdirs();
            }     

        }

        File file = new File(dir, filename);
        try {
            FileOutputStream mFileOutputStream=new FileOutputStream(file);

            DropboxFileInfo mDropboxFileInxfo=mApi.getFile(PHOTO_DIR + filename, null, mFileOutputStream, null);

            } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            } catch (DropboxException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            }
    }


    protected String doInBackground(String... params) {

         SessionUtil ses = new SessionUtil(mContext);
            AndroidAuthSession session = ses.buildSession();
            mApi = new DropboxAPI<AndroidAuthSession>(session);


        Entry entries = null;

        try {
            System.out.println("mApi is " + mApi);
            entries = mApi.metadata(PHOTO_DIR, 10000, null, true, null);
        } catch (DropboxException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        int size = entries.contents.size();
        int i = 0 ;
        for (Entry e : entries.contents) {
            if (!e.isDeleted) {
                //Log.i("Is Folder",String.valueOf(e.isDir));
                downloadFiles(e.fileName());
                 mFileLen = entries.bytes;
                Log.i("Item Name",e.fileName());
            }
            publishProgress(i * 100/size);
            i++;

        }



       return null;
    }

    protected void onProgressUpdate(Integer... progress) {
        mProgressBar.setProgress(values[0]);

    }

    @Override
    protected void onPostExecute(String result) {
        mProgressBar.setVisibility(ProgressBar.INVISIBLE);



    }

Answer 4

您需要在doInBackground中调用publishProgress方法。您需要将进度作为publishProgress方法的参数传递。

例如：

protected String doInBackground(String... params) {

         SessionUtil ses = new SessionUtil(mContext);
            AndroidAuthSession session = ses.buildSession();
            mApi = new DropboxAPI<AndroidAuthSession>(session);


        Entry entries = null;

        try {
            System.out.println("mApi is " + mApi);
            entries = mApi.metadata(PHOTO_DIR, 10000, null, true, null);
        } catch (DropboxException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

        int max = entries.contents.size(); // 2 variables need to calculate progress
        int current = 0;

        for (Entry e : entries.contents) {
            if (!e.isDeleted) {
                //Log.i("Is Folder",String.valueOf(e.isDir));
                downloadFiles(e.fileName());
                 mFileLen = entries.bytes;
                Log.i("Item Name",e.fileName());

                current++; //calculate your progress
                publishProgress(100 * current / max); //then pass it
            }
        }



       return null;
    }

调用publishProgress后将调用onProgressUpdate。

您需要像这样处理进度更新

protected void onProgressUpdate(Integer... progress) {
     Integer p = progress[0];
     mDialog.setProgress(p);
     mDialog.setMessage(String.format("%d%%", p)); //if you need to see progress percentage in dialog's text
}

Android - 通过更新进度条下载文件

4 个答案: