Question

i got some problem to show correctly a ProgressDialog during an image upload.
I’ve made the HTTPRequest in a AsynkTask and i update the progress bar using doInBackground() and progressUpdate() method, but something’s wrong. When i start the Task from the main activity the ProgressDialog does’t start but it shows itself only after the end of the upload.

Here is the code of the Task:

public class HTTPReqPostTask extends AsyncTask<Void, Integer, String>
{
private funzioni func = new funzioni();
private static final String TAG = "MotoRnUpload";
private ProgressBar progress;
private final Foto img;
private final Album al;
private final URL endpoint;
private String result;
private byte[] bytes;
private ProgressDialog dialog;
private Activity parent;

public HTTPReqPostTask(Activity act,final Foto f,final Album a,final URL u){
    parent = act;
    img = f;
    al = a;
    endpoint = u;
    result = null;
    bytes = func.imgToBytes2(img);        
}

@Override
protected void onPreExecute() {
    dialog = new ProgressDialog(parent);
    dialog.setMessage("Uploading...");
    dialog.setIndeterminate(false);
    dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
    dialog.setProgress(0);        
    dialog.show();        
}

/*
 * 
 */
@Override
protected String doInBackground(final Void... args)
{
final String CrLf = "\r\n";

int i=0,w,h; 
HttpURLConnection urlc = null;
DataOutputStream printout;
Bitmap b_img = BitmapFactory.decodeFile((img.getFile()).getAbsolutePath());

w = b_img.getWidth();
h = b_img.getHeight();

if(img.getRotationL() == 1 || img.getRotationR() == 1){
        int dim;
        dim = w;
        w = h;
        h = dim;
}

String message1="",message2="",message3="",message4="",message5="",message6="",message7="",message8="",
                message9="",message10="",message11="",message12="",message14="";
try
{
        urlc = (HttpURLConnection) endpoint.openConnection();
        try
        {
                urlc.setRequestMethod("POST");
                urlc.setRequestProperty("Connection", "Keep-Alive");
        } catch (ProtocolException e)
                {
                    Log.e(TAG, e.getMessage(),e.fillInStackTrace());
                }
        urlc.setDoOutput(true);
        urlc.setDoInput(true);
        urlc.setUseCaches(false);
        urlc.setAllowUserInteraction(false);

        message1 += "-----------------------------4664151417711" + CrLf;
        message1 += "Content-Disposition: form-data; name=\"uploadedfile\"; filename=\"test"+bytes.length+".jpg\"" + CrLf;
        message1 += "Content-Type: image/jpeg" + CrLf;
        message1 += CrLf;
        // the image is sent between the messages in the multipart message.
        message2 += CrLf + "-----------------------------4664151417711--" + CrLf;
        //dati normali
        message3 += "-----------------------------4664151417711" + CrLf;
        message3 += "Content-Disposition: form-data; name=\"nomeFoto\"" + CrLf +CrLf;
        //
        message4 += "-----------------------------4664151417711" + CrLf;
        message4 += "Content-Disposition: form-data; name=\"idCat\"" + CrLf +CrLf;
        //
        message5 += "-----------------------------4664151417711" + CrLf;
        message5 += "Content-Disposition: form-data; name=\"idAlbum\"" + CrLf +CrLf;
        //
        message6 += "-----------------------------4664151417711" + CrLf;
        message6 += "Content-Disposition: form-data; name=\"nomeAlbum\"" + CrLf +CrLf;
        //
        message7 += "-----------------------------4664151417711" + CrLf;
        message7 += "Content-Disposition: form-data; name=\"idUser\"" + CrLf +CrLf;
        //
        message8 += "-----------------------------4664151417711" + CrLf;
        message8 += "Content-Disposition: form-data; name=\"isPrivato\"" + CrLf +CrLf;
        //
        message9 += "-----------------------------4664151417711" + CrLf;
        message9 += "Content-Disposition: form-data; name=\"isNew\"" + CrLf +CrLf;
        //
        message10 += "-----------------------------4664151417711" + CrLf;
        message10 += "Content-Disposition: form-data; name=\"width\"" + CrLf +CrLf;
        //
        message11 += "-----------------------------4664151417711" + CrLf;
        message11 += "Content-Disposition: form-data; name=\"height\"" + CrLf +CrLf;
        //
        message12 += "-----------------------------4664151417711" + CrLf;
        message12 += "Content-Disposition: form-data; name=\"gps_lat\"" + CrLf +CrLf;
        //
        message14 += "-----------------------------4664151417711" + CrLf;
        message14 += "Content-Disposition: form-data; name=\"gps_lon\"" + CrLf +CrLf;
        //
        urlc.setRequestProperty("Content-Type", "multipart/form-data; boundary=---------------------------4664151417711");
        // might not need to specify the content-length when sending chunked data.
        //urlc.setRequestProperty("Content-Length", String.valueOf((message1.length() + String.valueOf(message2.length()) + String.valueOf(bytes.length) )));


        printout = new DataOutputStream (urlc.getOutputStream());
        //
        // invia il nome del file
        //
        printout.write(message3.getBytes());
        printout.writeBytes(img.getNome());
        printout.writeBytes(CrLf);
        //
        printout.write(message10.getBytes());
        printout.writeBytes(Integer.toString(w));
        printout.writeBytes(CrLf);
        //
        printout.write(message11.getBytes());
        printout.writeBytes(Integer.toString(h));
        printout.writeBytes(CrLf);
        //
        printout.write(message7.getBytes());
        printout.writeBytes(Integer.toString(img.getIdUser()));
        printout.writeBytes(CrLf);
        //
        printout.write(message9.getBytes());
        printout.writeBytes(Boolean.toString(al.isNew()));
        printout.writeBytes(CrLf);
        //
        if(img.hasGps()){
                printout.write(message12.getBytes());
                printout.writeBytes(img.getGpsLat());
                printout.writeBytes(CrLf);
                //
                printout.write(message14.getBytes());
                printout.writeBytes(img.getGpsLon());
                printout.writeBytes(CrLf);
                //
        }
        //
        if(al.isNew()){
                printout.write(message4.getBytes());
                printout.writeBytes(Integer.toString(al.getIdCat()));
                printout.writeBytes(CrLf);
                //
                printout.write(message6.getBytes());
                printout.writeBytes(al.getNome());
                printout.writeBytes(CrLf);
                //
                printout.write(message8.getBytes());
                printout.writeBytes(Boolean.toString(al.isPrivato()));
                printout.writeBytes(CrLf);
        }else{
                printout.write(message5.getBytes());
                printout.writeBytes(Integer.toString(al.getId()));
                printout.writeBytes(CrLf);
        }
        //
        // invia la foto
        //
        printout.write(message1.getBytes());

        // SEND THE IMAGE
        int size = 1024;    
        do{         
            publishProgress(i);
            if((i+size)>bytes.length){
                size = bytes.length - i;
            }
            printout.write(bytes, i, size);
            i+=size;                
        }while(i<bytes.length);
        publishProgress(bytes.length);
        //
        printout.write(message2.getBytes()); 
        printout.flush ();
        printout.close ();
        Log.i(TAG, "Immagine inviata");            
        //Get the response
        BufferedReader rd = new BufferedReader(new InputStreamReader(urlc.getInputStream()));
        StringBuffer sb = new StringBuffer();
        String line;
        while ((line = rd.readLine()) != null)
        {
            sb.append(line);
        }   
        rd.close();
        result = sb.toString();
} catch (Exception e)
{
    Log.e(TAG,e.toString(),e.fillInStackTrace());
}
return result;
}

@Override
protected void onProgressUpdate(final Integer... values) {
    dialog.setProgress(values[0]);
}

@Override
protected void onPostExecute(final String res) {
    dialog.dismiss();
}
}

This is the part of code that call the task from the main Activity class:

public void onClick(View view) {
    if(view.getId() == R.id.button1){
        try{
            String result;
            JSONObject info_upload;
            result = new HTTPReqPostTask(MainActivity.this,foto,alb,new               URL(urlUpload)).execute().get();
            info_upload = new JSONObject(result);
            if(info_upload.getString("stato").equals("fail")){
                funzioni.popUp(MainActivity.this,"Errore caricamento foto: "+info_upload.getString("info"));                    
            }else{
                funzioni.popUp(MainActivity.this,"Foto caricata correttamente su MotoRn");
                if(info_upload.getString("stato").equals("create")){
                    alb.setId(info_upload.getInt("id_album"));
                    alb.setIsNew(false);
                }
            }
        }catch(MalformedURLException mue){
            Log.e(TAG,mue.toString(),mue.fillInStackTrace());
            funzioni.popUp(MainActivity.this, mue.getMessage()+" : "+mue.getLocalizedMessage());
        }catch(Exception e){
            Log.e(TAG,e.toString(),e.fillInStackTrace());
            funzioni.popUp(MainActivity.this, e.getMessage()+" : "+e.getLocalizedMessage());
        }
    }else if(view.getId() == R.id.b_open ){
        startActivityForResult(new Intent(Intent.ACTION_PICK,
            android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI), SELECT_IMAGE_CODE);
    }
}

Thank you for the support 😉

Answer 1

try to pass the real context at that time and i believe you are trying to pass the result of the async task to the String variable “result”. The main thread has to wait until the async task has finished, so its hanging and thus cannot show the dialog.