android - 上载图片时，ProgressDialog不显示

Question

我有一个用于将图像上传到服务器的类。
上传时，我想显示一个progressDialog来显示上传进度。
但是进度条没有显示出来。
这是我的ImageUploader类:

package com.OBO.Bandenanalyse;

//Imagine Imports here    

public class ImageUploader {
private Context context;
private ProgressDialog dialog;

public ImageUploader(Context ctx) {
    this.context = ctx;
    ((Activity) context).runOnUiThread(new Runnable() {
        @Override
        public void run() {
            dialog = new ProgressDialog(context);
            dialog.setCancelable(false);
            dialog.setMessage("Uploading Image... Please wait!");
            dialog.show();
        }
    });
}

private static String serverResponseMessage = "";
private static int serverResponseCode = 0;

public int uploadFile(final String sourceFileUri, final String serverFile) {

    Debug.out("SourceFileUri: " + sourceFileUri);
    Debug.out("ServerFile: " + serverFile);
    Thread thread = new Thread() {
        @Override
        public void run() {
            String upLoadServerUri = serverFile;
            String fileName = sourceFileUri;
            HttpURLConnection conn = null;
            DataOutputStream dos = null;
            String lineEnd = "\r\n";
            String twoHyphens = "--";
            String boundary = "*****";
            int bytesRead, bytesAvailable, bufferSize;
            byte[] buffer;
            int maxBufferSize = 1 * 1024 * 1024;
            File sourceFile = new File(sourceFileUri);
            if (!sourceFile.isFile()) {
                Log.e("uploadFile", "Source File Does not exist");
            }
            try { // open a URL connection to the Servlet
                Debug.out("in the try");
                FileInputStream fileInputStream = new FileInputStream(
                        sourceFile);
                URL url = new URL(upLoadServerUri);
                conn = (HttpURLConnection) url.openConnection(); // Open a
                                                                    // HTTP
                                                                    // connection
                                                                    // to
                                                                    // the
                                                                    // URL
                conn.setDoInput(true); // Allow Inputs
                conn.setDoOutput(true); // Allow Outputs
                conn.setUseCaches(false); // Don't use a Cached Copy
                conn.setRequestMethod("POST");
                conn.setRequestProperty("Connection", "Keep-Alive");
                conn.setRequestProperty("ENCTYPE", "multipart/form-data");
                conn.setRequestProperty("Content-Type",
                        "multipart/form-data;boundary=" + boundary);
                conn.setRequestProperty("uploaded_file", fileName);
                dos = new DataOutputStream(conn.getOutputStream());
                Debug.out("Set Properties and Datastream");
                dos.writeBytes(twoHyphens + boundary + lineEnd);
                dos.writeBytes("Content-Disposition: form-data; name=\"uploaded_file\";filename=\""
                        + fileName + "\"" + lineEnd);
                dos.writeBytes(lineEnd);
                Debug.out("Writes data");
                bytesAvailable = fileInputStream.available(); // create a
                                                                // buffer of
                                                                // maximum
                                                                // size

                bufferSize = Math.min(bytesAvailable, maxBufferSize);
                buffer = new byte[bufferSize];
                Debug.out("Buffer done");
                // read file and write it into form...
                bytesRead = fileInputStream.read(buffer, 0, bufferSize);
                Debug.out("Read Bytes");
                while (bytesRead > 0) {
                    dos.write(buffer, 0, bufferSize);
                    bytesAvailable = fileInputStream.available();
                    bufferSize = Math.min(bytesAvailable, maxBufferSize);
                    bytesRead = fileInputStream.read(buffer, 0, bufferSize);
                }

                // send multipart form data necesssary after file data...
                dos.writeBytes(lineEnd);
                dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
                Debug.out("After sendData");
                // Responses from the server (code and message)
                serverResponseCode = conn.getResponseCode();
                serverResponseMessage = conn.getResponseMessage();
                Debug.out("Server Response: " + serverResponseCode);
                Log.i("uploadFile", "HTTP Response is : "
                        + serverResponseMessage + ": " + serverResponseCode);
                Debug.out("HTTP Response is : " + serverResponseMessage
                        + ": " + serverResponseCode);
                // close the streams //
                fileInputStream.close();
                dos.flush();
                dos.close();
                dialog.dismiss();
            }

            catch (MalformedURLException ex) {
                dialog.dismiss();
                ex.printStackTrace();
                // Toast.makeText(UploadImageDemo.this,
                // "MalformedURLException", Toast.LENGTH_SHORT).show();
                Log.e("Upload file to server", "error: " + ex.getMessage(),
                        ex);
            } catch (Exception e) {
                dialog.dismiss();
                e.printStackTrace();
                // Toast.makeText(UploadImageDemo.this, "Exception : " +
                // e.getMessage(), Toast.LENGTH_SHORT).show();
                Log.e("Upload file to server Exception",
                        "Exception : " + e.getMessage(), e);
            }

        }
    };
    thread.start();
    try {
        thread.join();
        Debug.out("done uploading");
        dialog.dismiss();
    } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    Debug.out("Message: " + serverResponseMessage.toString());
    return serverResponseCode;
}

}

我在AsyncTask中调用该函数，因为我也需要做其他事情。我这样做是这样的:

private class MyAsyncTask extends AsyncTask<Mail, Integer, Double>{
    /**
     * Private boolean to check if a tire is repairable or not.</br>
     */
    boolean _repairable = Step4._isRepairable;

    /**
     * Private integer which counts how many times we've tried to send the Email.
     */
    private int _counter = 0;

    private ProgressDialog dialog;

    @Override
    protected void onPreExecute(){
        super.onPreExecute();
        if(isPhotoTaken()){
            ImageUploader uploader = new ImageUploader(_context);
            uploader.uploadFile(getPhotoPath(), "http://obo.nl/android-upload-image.php");              
        }
    }

    /**
     * Method used to start {@link #postData(Mail)} on a background thread.
     * 
     * @return null
     */
    @Override
    protected Double doInBackground(Mail... params) {
        postData(params[0]);
        return null;
    }

    /**
     * Method used to send the mail through a JSON Request in combination with the website.
     * If there is no Internet connection the program will try to send the mail every 10 seconds.
     * 
     * @param valueIWantToSend
     */
    public void postData(Mail valueIWantToSend) {
        if(AppStatus.haveNetworkConnection(_context)){
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost("http://obo.nl/android-mailing.php");
            try {
                List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
                nameValuePairs.add(new BasicNameValuePair("from", valueIWantToSend.getFrom()));
                nameValuePairs.add(new BasicNameValuePair("to", valueIWantToSend.getTo()));
                nameValuePairs.add(new BasicNameValuePair("subject", valueIWantToSend.getSubject()));
                nameValuePairs.add(new BasicNameValuePair("message", valueIWantToSend.getBody()));
                nameValuePairs.add(new BasicNameValuePair("localized", getResources().getConfiguration().locale.getDisplayName()));
                if(PathToPDF(_repairable).contains("Goed_Gekeurd_NL")){
                    nameValuePairs.add(new BasicNameValuePair("outputResult", SERVER_BANDENANALYSE_GOED_GEKEURD_PATH));
                } else if(PathToPDF(_repairable).contains("Afgekeurd_NL")){
                    nameValuePairs.add(new BasicNameValuePair("outputResult", SERVER_BANDENANALYSE_AFGEKEURD_PATH));
                } else if(PathToPDF(_repairable).contains("Goed_Gekeurd_FR")){
                    nameValuePairs.add(new BasicNameValuePair("outputResult", SERVER_ANALYSEPNEUS_GOED_GEKEURD_PATH));
                } else if(PathToPDF(_repairable).contains("Afgekeurd_FR")){
                    nameValuePairs.add(new BasicNameValuePair("outputResult", SERVER_ANALYSEPNEUS_AFGEKEURD_PATH));
                } else if(PathToPDF(_repairable).contains("Goed_Gekeurd_DE")){
                    nameValuePairs.add(new BasicNameValuePair("outputResult", SERVER_REIFENANALYSE_GOED_GEKEURD_PATH));
                } else if(PathToPDF(_repairable).contains("Afgekeurd_DE")){
                    nameValuePairs.add(new BasicNameValuePair("outputResult", SERVER_REIFENANALYSE_AFGEKEURD_PATH));
                } else if(PathToPDF(_repairable).contains("Goed_Gekeurd_EN")){
                    nameValuePairs.add(new BasicNameValuePair("outputResult", SERVER_TYREANALYSE_GOED_GEKEURD_PATH));
                } else if(PathToPDF(_repairable).contains("Afgekeurd_EN")){
                    nameValuePairs.add(new BasicNameValuePair("outputResult", SERVER_TYREANALYSE_AFGEKEURD_PATH));
                }
                if(isPhotoTaken()){

//ImageUploader uploader = new ImageUploader(_context);
//uploader.uploadFile(getPhotoPath()，“http://obo.nl/android-upload-image.php”);
nameValuePairs.add(new BasicNameValuePair(“photo”，getPhotoPath()));
}
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
ResponseHandler responseHandler = new BasicResponseHandler();
字符串响应= httpclient.execute(httppost，responseHandler);

                //This is the response from a php application
                String reverseString = response;
                Log.i("info", reverseString);

                } catch (ClientProtocolException e) {

                } catch (IOException e) {

                }
        } else {
            if(_counter == 0){
                _counter++;
                _activity.runOnUiThread(new Runnable(){
                    public void run(){
                        Toast.makeText(_context, getString(R.string.noInternetEmailNotSend), Toast.LENGTH_LONG).show();
                    }
                });

            }
            try {
                Thread.sleep(10000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            postData(valueIWantToSend);
        }
    }

}

此外，_context在 Activity 的onCreate中设置如下:

_context = this;

在PostData方法中发生的事情是发送邮件，并将所拍摄的照片作为附件(但这并不是很有趣，因为它工作得很好)。

那么，对话框怎么不显示呢？

Answer 1

您没有在ImageUploader方法中启动线程。将您的方法更改为此:

public ImageUploader(Context ctx) {
this.context = ctx;
((Activity) context).runOnUiThread(new Runnable() {
    @Override
    public void run() {
        dialog = new ProgressDialog(context);
        dialog.setCancelable(false);
        dialog..setProgressStyle(ProgressDialog.STYLE_SPINNER);
        dialog.setMessage("Uploading Image... Please wait!");
        dialog.show();
    }
}).start();
}