如何使用来自SQL Server 2008的动态数据填充微调器

Question

I am making an android application in which I want to populate a spinner with an array of string values, coming from SQLServer 2008. I am having a problem in which it says that the spinner cannot be populated from a thread different from the main thread.

       Thread waitth = new Thread() {
         public void run() {
             try {
                    System.out.println("3");

                 String details="mani";
                        System.out.println("4");
                        URLConnection con = getServletConnection();
                        System.out.println("5");
                        ObjectOutputStream oos = new ObjectOutputStream(con.getOutputStream());
                        System.out.println("7");
                        oos.writeObject(details);
                        System.out.println("8");
                        oos.flush();
                        oos.close();
                        // receive result from servlet
                        InputStream inputStream = con.getInputStream();
                        ObjectInputStream inputFromServlet = new ObjectInputStream(
                                inputStream);
                        result = (String[]) inputFromServlet.readObject();
                        //System.out.println(result);
                        inputFromServlet.close();
                        inputStream.close();
                        System.out.println();
                        System.out.println("got it");

                    System.out.println("450200");


                    ArrayList<String> aus=new ArrayList<String>();
                    for(int i=0;i<result.length;i++)
                    aus.add(result[i]);
                 ArrayAdapter<String> adapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_spinner_item, aus);
                    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                   s1=(Spinner)findViewById(R.id.spinner1);

                        s1.setAdapter(adapter);




             }  
            catch (Exception ex) {
              ex.printStackTrace();
            }
         }
            };
            waitth.start();


    }


    private URLConnection getServletConnection() throws MalformedURLException,
       IOException {
    URL urlServlet = new URL("http://ipaddress/spinnerfordata");//servlet
    URLConnection con = urlServlet.openConnection();
    con.setUseCaches (false); 
       con.setDefaultUseCaches(false);
    con.setDoInput(true);
    con.setDoOutput(true);
    con.setUseCaches(false);
    con.setRequestProperty("Content-Type","application/x-java-serialized-object");
    System.out.println("9");
    return con;

  }

Logcat error:

      08-02 18:49:08.439: W/System.err(918):                      android.view.ViewRootImpl$CalledFromWrongThreadException  : Only the original thread that created a view hierarchy can touch its views.
08-02 18:49:08.454: W/System.err(918):  at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:4746)
08-02 18:49:08.454: W/System.err(918):  at android.view.ViewRootImpl.focusableViewAvailable(ViewRootImpl.java:2588)
08-02 18:49:08.454: W/System.err(918):  at android.view.ViewGroup.focusableViewAvailable(ViewGroup.java:608)
08-02 18:49:08.454: W/System.err(918):  at android.view.ViewGroup.focusableViewAvailable(ViewGroup.java:608)
08-02 18:49:08.454: W/System.err(918):  at android.view.ViewGroup.focusableViewAvailable(ViewGroup.java:608)
08-02 18:49:08.454: W/System.err(918):  at android.view.ViewGroup.focusableViewAvailable(ViewGroup.java:608)
08-02 18:49:08.454: W/System.err(918):  at android.view.View.setFlags(View.java:8412)
08-02 18:49:08.464: W/System.err(918):  at android.view.View.setFocusable(View.java:5769)
08-02 18:49:08.464: W/System.err(918):  at android.widget.AdapterView.checkFocus(AdapterView.java:718)
08-02 18:49:08.464: W/System.err(918):  at android.widget.AbsSpinner.setAdapter(AbsSpinner.java:115)
08-02 18:49:08.464: W/System.err(918):  at android.widget.Spinner.setAdapter(Spinner.java:380)
08-02 18:49:08.464: W/System.err(918):  at com.example.manispinner.MainActivity$1.run(MainActivity.java:73)

Answer 1

you are trying to update the UI from a non-UI thread, you cannot do that as the error says. anything relating to the UI needs to be done on the UI thread

Answer 2

1. Get the data using an API, from the server, either xml or json
2. Parse the data.

3. store it in an array.

    Do all the above in AsyncTask. 

4. Finally populate it to the spinner.

Find an example project at GitHub Spinner-Dynamic