应用程序适用于版本2.2和2.3，但在最新版本上失败

Question

我正在开发一个Android应用程序而且我遇到了问题; 我有兼容性错误;我的应用程序与版本2.2和2.3一起正常工作，但在比2.3更新的版本中，只有第一个类正确执行（只包含一个图像和progressBar），之后，我得到一个android运行时错误 那么你们中的任何人都可以帮助我吗？

MainActivty.java：

    public class MainActivity extends Activity {
    int myProgress=0;
    ProgressDialog pg;
    ProgressBar b;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main); 
        b=(ProgressBar)findViewById(R.id.progressBar1);
        Test t= new Test();
        t.execute();} 
    private class Test extends AsyncTask<Void, Integer, String> {
    @Override
    protected void onPreExecute(){
        super.onPreExecute();
        myProgress=0;
    }
    @Override
    protected String doInBackground(Void... arg0) {
        String ch = "non connecter";
        ConnectivityManager cm =(ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo netInfo = cm.getActiveNetworkInfo();
                if (netInfo != null && netInfo.isConnected()) {
                    while(myProgress<100){     
                        myProgress++;
                        b.setProgress(myProgress);
                        SystemClock.sleep(30);  
                        ch="connecter";
                        }
                }
                else{
                        ch="non connecter";
                }
                return ch;
            }
    @Override
    protected void onPostExecute(String result) {
        if(result.equals("non connecter")){             
            AlertDialog.Builder adb = new AlertDialog.Builder(MainActivity.this);
            adb.setMessage("Problème de connexion !!");
            adb.setPositiveButton("Ok",new DialogInterface.OnClickListener() { 
                public void onClick(DialogInterface dialog, int which) {
                    System.exit(0);
                }
                });
            adb.show();
            }

            else{
                startActivity(new Intent(MainActivity.this, Choix.class));
                finish();

            }
        }   
}
}

Choix.java：

 public class Choix extends Activity {
    JSONArray ja1 = null;
    String ch2="";String ch3="";
    TextView t1,t2;
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.choix_espace); 
        Button b_p=(Button)findViewById(R.id.b_par);
        Button b_en=(Button)findViewById(R.id.b_prof);
        Button b_el=(Button)findViewById(R.id.b_el);
        Button b_ad=(Button)findViewById(R.id.b_admin);
        try{
            URL url2 = new URL("http://192.168.1.3/web_service/ecole.php");
            HttpURLConnection httpconn2 = (HttpURLConnection)url2.openConnection();

            if (httpconn2.getResponseCode() == HttpURLConnection.HTTP_OK){
                try{ BufferedReader input = new BufferedReader(new InputStreamReader(httpconn2.getInputStream()),8192);
                 String line1 = null;
                 while ((line1 = input.readLine()) != null){
                     ja1 = new JSONArray(line1);}
                 for (int i = 0; i < ja1.length(); i++) {
                     JSONObject jo1 = null;
                     jo1 = (JSONObject) ja1.getJSONObject(i);
                     ch2 = jo1.getString("nom_ecole");
                     ch3 = jo1.getString("annee_scolaire");
                 }
                 }
                finally{
                    httpconn2.disconnect();
                }
                }

            }catch (JSONException e) {
                System.out.print("vérifier !");e.printStackTrace();} catch (MalformedURLException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}
        t1=(TextView)findViewById(R.id.nom);
        t1.setText(Farsi.Convert(ch2));
        t1.setTextColor(getResources().getColor(R.color.blue));
        t2=(TextView)findViewById(R.id.ann);
        t2.setText(Farsi.Convert(ch3));
        t2.setTextColor(getResources().getColor(R.color.blue));
        b_p.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                Intent i = new Intent(Choix.this,Identi.class);
                i.putExtra("id","parent");
                Choix.this.startActivity(i);
            }
        });
        b_en.setOnClickListener(new OnClickListener() {
            public void onClick(View v){
                Intent i = new Intent(Choix.this,Identi.class);
                i.putExtra("id","enseignant");
                Choix.this.startActivity(i);
            }
        });
        b_el.setOnClickListener(new OnClickListener() {
            public void onClick(View v){
                Intent i = new Intent(Choix.this,Identi.class);
                i.putExtra("id","eleve");
                Choix.this.startActivity(i);
            }
        });
        b_ad.setOnClickListener(new OnClickListener() {
            public void onClick(View v){
                Intent i = new Intent(Choix.this,Identi.class);
                i.putExtra("id","admin");
                Choix.this.startActivity(i);
            }
        });}
}

Answer 1

对于choix.java类，您需要执行ASYNC任务中的所有网络操作。你是在主线程上做的。将网络代码放入ASYNC任务。