Question

我的应用将文件转换为字节。我想在进行转换时显示进度条。但是，仅在转换完成时才会显示进度条。这是代码：

 public static void fileToByte(Context context) {
    progressDialog = new ProgressDialog(context);
    progressDialog.setMessage("Loading..."); // Setting Message
    progressDialog.setTitle("ProgressDialog"); // Setting Title
    progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER); // Progress Dialog Style Spinner
    progressDialog.setCancelable(false);
    progressDialog.show();

    File file = new File(path);
    int size = (int) file.length();
    byte[] bytes = new byte[size];
    try {
        BufferedInputStream buf = new BufferedInputStream(new FileInputStream(file));
        buf.read(bytes, 0, bytes.length);
        buf.close();
        txt_out.setText(new String(bytes));
    }
    catch (FileNotFoundException e) {
        Toast.makeText(context, "File Not Found" + e, Toast.LENGTH_LONG);
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

更新：我使用Async并且它的工作在STYLE_SPINNER上没有旋转

 public class FileToByte extends AsyncTask<Void , Void, Void> {
    ProgressDialog progressDialog;
    byte[] bytes;
    @Override
    protected void onPreExecute() {
        progressDialog = new ProgressDialog(MainActivity.this);
        progressDialog.setMessage("Loading..."); // Setting Message
        progressDialog.setTitle("ProgressDialog"); // Setting Title
        progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER); // Progress Dialog Style Spinner
        progressDialog.setCancelable(false);
        progressDialog.show();
    }

    protected Void doInBackground(Void... voids) {
        File file = new File(path);
        int size = (int) file.length();
        bytes = new byte[size];
        try {
            BufferedInputStream buf = new BufferedInputStream(new FileInputStream(file));
            buf.read(bytes, 0, bytes.length);
            buf.close();
        }
        catch (FileNotFoundException e) {
            Toast.makeText(MainActivity.this, "File Not Found" + e, Toast.LENGTH_LONG);
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
        txt_out.setText(new String(bytes));
        progressDialog.dismiss();
    }
}

Answer 1

使用这个例子来做你需要的事情。

protected class AsyncLogin extends AsyncTask<String, JSONObject, Boolean> {

            String email=null;
            @Override
            protected Boolean doInBackground(String... params) {

                RestAPI api = new RestAPI();
                boolean userAuth = false;
                try {

                    // Call the User Authentication Method in API
                    JSONObject jsonObj = api.UserAuthentication(params[0],
                            params[1]);

                    //Parse the JSON Object to boolean
                    JSONParser parser = new JSONParser();
                    userAuth = parser.parseUserAuth(jsonObj);
                    email=params[0];
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    Log.d("AsyncLogin", e.getMessage());

                }
                return userAuth;
            }

            @Override
            protected void onPreExecute() {
                super.onPreExecute();
                progressBar = new ProgressDialog(getContext());
                progressBar.setCancelable(true);
                progressBar.setMessage("Please Wait...");
                progressBar.setProgressStyle(ProgressDialog.STYLE_SPINNER);
                progressBar.setIndeterminate(true);
                progressBar.show();
                //Toast.makeText(context, "Please Wait...", Toast.LENGTH_SHORT).show();
            }

            @Override
            protected void onPostExecute(Boolean result) {
                //Check user validity
                if (result) {
                    FragmentManager frag = getFragmentManager();
                    FragmentTransaction ftran = frag.beginTransaction();
                    Fragment fragprofil = new Profils();
                    ftran.replace(R.id.main_content, fragprofil);
                    ftran.commit();
                    progressBar.cancel();
                }
                else
                {
                    Toast.makeText(context, "Not valid email/password ",Toast.LENGTH_SHORT).show();
                    progressBar.cancel();
                }

            }


        }

致电使用：

new AsyncLogin().execute(email, password);

在Android中创建一个进度条

1 个答案: