2015-11-14 53 views
0

我有以下assynctask實施。它的使用非常簡單,並且按照預期工作。獲取一個url,發佈到它,獲取它的內容,將它們寫入一個文件。困難的部分現在開始android異步任務返回類型和鎖定

問題: 我需要多次重複使用這段代碼多個不同的文件。如何將文件作爲變量傳遞給url的assynctask調用?

//class to call a url and save it to a local file 
     private class url_to_file extends AsyncTask<String, Integer, String> { 

      protected String[] doInBackground(String... input) { 
       //function to call url and postback contents 
       return callpost(input[0]); 
      } 

      protected void onProgressUpdate(Integer... progress) { 
       //Yet to code 
      } 

      protected void onPostExecute(String result) { 
       //function to write content to text file 
       writeStringAsFile(result, "file.xml" ,getApplicationContext()); 

      } 
     } 

編輯: Purelly作爲參考,我用它來讀取,從文件和呼叫URL寫函數

//saves a txt (etc, xml as well) file to directory,replacing previous. if directory is left empty, save to assets 
    public static void writeStringAsFile(final String fileContents, String fileName ,Context context) { 
     try { 
      FileWriter out = new FileWriter(new File(context.getFilesDir(), fileName)); 
      out.write(fileContents); 
      out.close(); 
     } catch (IOException e) { 
     } 
    } 

    //read file, returns its contents 
    public static String readFileAsString(String fileName,Context context) { 
     StringBuilder stringBuilder = new StringBuilder(); 
     String line; 
     BufferedReader in = null; 

     try { 
      in = new BufferedReader(new FileReader(new File(context.getFilesDir(), fileName))); 
      while ((line = in.readLine()) != null) stringBuilder.append(line); 

     } catch (FileNotFoundException e) { 
     } catch (IOException e) { 
     } 

     return stringBuilder.toString(); 
    } 

    //calls a page. Returns its contents 
    public String callpost (String... strings) 
    { 
     StringBuilder content = new StringBuilder(); 
     try 
     { 
      // create a url object 
      URL url = new URL(strings[0]); 

      // create a urlconnection object 
      URLConnection urlConnection = url.openConnection(); 

      // wrap the urlconnection in a bufferedreader 
      BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream())); 

      String line; 

      // read from the urlconnection via the bufferedreader 
      while ((line = bufferedReader.readLine()) != null) 
      { 
       content.append(line + "\n"); 
      } 
      bufferedReader.close(); 
     } 
     catch(Exception e) 
     { 
      e.printStackTrace(); 
     } 

     return content.toString(); 
    } 

編輯: 刪除第二個問題,因爲它沒有任何關係,其餘的和會搞亂人們看到了線程

+0

Q1:也許創建一個構造函數和傳遞需要的值... [詳細](http://stackoverflow.com/a/11335798/4577762) - Q2:你想要某種甩幹過程酒吧,直到它完成? [更多](http://stackoverflow.com/questions/18069678/how-to-use-asynctask-to-display-a-progress-bar-that-c​​ounts-down) - 這最後一個鏈接,我沒有完全檢查。你還需要檢查所有的任務。 – FirstOne

+0

Q1我可以看到它爲我的需要工作,字符串屬性和設置功能將歸結爲相同的成就。將嘗試接下來的事情。至於第二季度,我對這個視覺部分並不那麼挑剔,我會弄清楚。問題是我怎麼能讓主線程瞭解所有的通話都已完成,並且可以繼續。 – Elentriel

回答

0

榮譽@FirstOne對他的幫助了在評論

,這使得它對於m Ë

//class to call a url and save it to a local file 
      private class url_to_file extends AsyncTask<String, Integer, String> { 
       protected String file; 
       public void setFile(String input) 
       { 
       file=input; 
       } 

       protected String[] doInBackground(String... input) { 
        //function to call url and postback contents 
        return callpost(input[0]); 
       } 

       protected void onProgressUpdate(Integer... progress) { 
        //Yet to code 
       } 

       protected void onPostExecute(String result) { 
        //function to write content to text file 
        writeStringAsFile(result, file ,getApplicationContext()); 

       } 
      }