Ich versuche mich einzuloggen. seine Arbeit, aber wenn es keine Internetverbindung gibt, zerstören die meine Apps

Question

das ist meine Login-Aktivität, die ich gemacht habe, gibt es ein Problem darin, wenn Internet-Verbindung verfügbar ist funktioniert es richtig, aber wenn es keine Internetverbindung gibt es abgestürzte Nachricht bitte helfen mir dieses Problem

zu lösen verwendet i Json

public class LoginActivity extends Activity implements OnClickListener{ 

private EditText etUser,etPassword; 
private ImageView bLogin,bCancel,bRegister; 
private Spinner spPermission; 
private static String[] PERMISSIONS = {"Admin","Donor","Accepter"}; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    // TODO Auto-generated method stub 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.login_layout); 

    etUser = (EditText)findViewById(R.id.etUserName); 
    etPassword = (EditText)findViewById(R.id.etPassword); 
    etUser.setText(""); 
    etPassword.setText(""); 

    spPermission = (Spinner)findViewById(R.id.spPermission); 

    ArrayAdapter<String> permAdapter = new ArrayAdapter<String>(LoginActivity.this,android.R.layout.simple_spinner_item,PERMISSIONS); 
    permAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
    spPermission.setAdapter(permAdapter); 

    bLogin = (ImageView)findViewById(R.id.imLogin); 
    bCancel= (ImageView)findViewById(R.id.imCancel); 
    bRegister = (ImageView)findViewById(R.id.imRegister); 

    bLogin.setOnClickListener(this); 
    bCancel.setOnClickListener(this); 
    bRegister.setOnClickListener(this); 
} 

@Override 
public void onClick(View view) { 

    switch(view.getId()) 
    { 
    case R.id.imLogin: 
     String uName = etUser.getText().toString(); 
     String password = etPassword.getText().toString(); 
     String type = spPermission.getSelectedItem().toString(); 
     String message = "POST"; 

     LoginTask task = new LoginTask(this); 
     task.execute(message,uName,password,type); 

     break; 
    case R.id.imCancel: 
     finish(); 
     break; 
    case R.id.imRegister: 
     startActivity(new Intent(getApplicationContext(), Registration.class)); 
     break; 
    default: 
     break; 
    } 

} 

public class LoginTask extends AsyncTask<String, Void, String>{ 

    private Context context; 
    private JSONParser jsonParser = new JSONParser(); 
    private JSONObject json; 
    private String login_url = //"http://192.168.1.3/login.php"; 
      "http://10.0.2.2/login.php"; 
    private String s; 
    private String USER_TYPE; 

    public LoginTask(Context c) 
    { 
     context = c; 
    } 
    @Override 
    protected String doInBackground(String... params) 
    { 

     String message = params[0]; 
     if(message.equals("POST")) 
     { 
      List<NameValuePair> list = new ArrayList<NameValuePair>(); 
      final String uName = params[1]; 
      final String uPass = params[2]; 
      final String uType = params[3]; 
      USER_TYPE = uType; 
      list.add(new BasicNameValuePair("username", uName)); 
      list.add(new BasicNameValuePair("password",uPass)); 
      list.add(new BasicNameValuePair("type", uType)); 

      json = jsonParser.makeHttpRequest(login_url, params[0], list); 
     } 
     try 
     { 
      s = json.getString("message"); 
     } catch (JSONException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
     return s; 
    } 
    @Override 
    protected void onPostExecute(String result) 
    { 
     try { 
      int success = json.getInt("success"); 
      if(success==1) 
      { 
       Toast.makeText(context, result, Toast.LENGTH_LONG).show(); 
       Intent i = new Intent(context.getApplicationContext(),MainView.class); 
       i.putExtra("type", USER_TYPE); 
       context.startActivity(i); 
      } 
      else 
       //Toast.makeText(context, result, Toast.LENGTH_LONG).show(); 
       Toast.makeText(context, "Sorry No connection", Toast.LENGTH_LONG).show(); 

     } catch (JSONException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 

    } 
} 

} 

Answer 1

Änderung youur doInBackground() Methode:

@Override 
protected String doInBackground(String... params) { 

    String message = params[0]; 
    if (message.equals("POST")) { 
     try { 
      List<NameValuePair> list = new ArrayList<NameValuePair>(); 
      final String uName = params[1]; 
      final String uPass = params[2]; 
      final String uType = params[3]; 
      USER_TYPE = uType; 
      list.add(new BasicNameValuePair("username", uName)); 
      list.add(new BasicNameValuePair("password", uPass)); 
      list.add(new BasicNameValuePair("type", uType)); 

      json = jsonParser.makeHttpRequest(login_url, params[0], list); 
     } 

     s = json.getString("message"); 
    }catch(Exception ex){ 
     ex.printStackTrace(); 
    }catch(JSONException e){ 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 
    return s; 
} 

} 

Answer 2

vor dem Aufruf von Ihrem Internet-con asyntask überprüfen bindung, wie folgend

Ort, um diese in einem gewissen Konstanten Klasse

public static boolean isConnectingToInternet(){ 
    ConnectivityManager connectivity = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); 
    if (connectivity != null) 
    { 
     NetworkInfo[] info = connectivity.getAllNetworkInfo(); 
     if (info != null) 
      for (int i = 0; i < info.length; i++) 
       if (info[i].getState() == NetworkInfo.State.CONNECTED) 
       { 
        return true; 
       } 

    } 
    return false; 
} 

und während mit folgenden

if(Constants.isConnectingToInternet()) {LoginTask task = new LoginTask(this); 
    task.execute(message,uName,password,type);} 

asyntask Check-Konnektivität Aufruf wird es auf jeden Fall funktionieren.

Answer 3

Sie Klasse wie sein

public class LoginActivity extends Activity implements OnClickListener{ 

    private EditText etUser,etPassword; 
    private ImageView bLogin,bCancel,bRegister; 
    private Spinner spPermission; 
    private static String[] PERMISSIONS = {"Admin","Donor","Accepter"}; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     // TODO Auto-generated method stub 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.login_layout); 
    Constants.context=this; 
     etUser = (EditText)findViewById(R.id.etUserName); 
     etPassword = (EditText)findViewById(R.id.etPassword); 
     etUser.setText(""); 
     etPassword.setText(""); 

     spPermission = (Spinner)findViewById(R.id.spPermission); 

     ArrayAdapter<String> permAdapter = new ArrayAdapter<String>(LoginActivity.this,android.R.layout.simple_spinner_item,PERMISSIONS); 
     permAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
     spPermission.setAdapter(permAdapter); 

     bLogin = (ImageView)findViewById(R.id.imLogin); 
     bCancel= (ImageView)findViewById(R.id.imCancel); 
     bRegister = (ImageView)findViewById(R.id.imRegister); 

     bLogin.setOnClickListener(this); 
     bCancel.setOnClickListener(this); 
     bRegister.setOnClickListener(this); 
    } 

    @Override 
    public void onClick(View view) { 

     switch(view.getId()) 
     { 
     case R.id.imLogin: 
      String uName = etUser.getText().toString(); 
      String password = etPassword.getText().toString(); 
      String type = spPermission.getSelectedItem().toString(); 
      String message = "POST"; 
    if(Constants.isConnectingToInternet()) {LoginTask task = new LoginTask(this); 
task.execute(message,uName,password,type);} 


      break; 
     case R.id.imCancel: 
      finish(); 
      break; 
     case R.id.imRegister: 
      startActivity(new Intent(getApplicationContext(), Registration.class)); 
      break; 
     default: 
      break; 
     } 

    } 

    public class LoginTask extends AsyncTask<String, Void, String>{ 

     private Context context; 
     private JSONParser jsonParser = new JSONParser(); 
     private JSONObject json; 
     private String login_url = //"http://192.168.1.3/login.php"; 
       "http://10.0.2.2/login.php"; 
     private String s; 
     private String USER_TYPE; 

     public LoginTask(Context c) 
     { 
      context = c; 
     } 
     @Override 
     protected String doInBackground(String... params) 
     { 

      String message = params[0]; 
      if(message.equals("POST")) 
      { 
       List<NameValuePair> list = new ArrayList<NameValuePair>(); 
       final String uName = params[1]; 
       final String uPass = params[2]; 
       final String uType = params[3]; 
       USER_TYPE = uType; 
       list.add(new BasicNameValuePair("username", uName)); 
       list.add(new BasicNameValuePair("password",uPass)); 
       list.add(new BasicNameValuePair("type", uType)); 

       json = jsonParser.makeHttpRequest(login_url, params[0], list); 
      } 
      try 
      { 
       s = json.getString("message"); 
      } catch (JSONException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
      return s; 
     } 
     @Override 
     protected void onPostExecute(String result) 
     { 
      try { 
       int success = json.getInt("success"); 
       if(success==1) 
       { 
        Toast.makeText(context, result, Toast.LENGTH_LONG).show(); 
        Intent i = new Intent(context.getApplicationContext(),MainView.class); 
        i.putExtra("type", USER_TYPE); 
        context.startActivity(i); 
       } 
       else 
        //Toast.makeText(context, result, Toast.LENGTH_LONG).show(); 
        Toast.makeText(context, "Sorry No connection", Toast.LENGTH_LONG).show(); 

      } catch (JSONException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 

     } 
    } 

    } 

und Ihre Konstanten Klasse

public class Constants { 
    public static final Context context=null; 
    public static boolean isConnectingToInternet(){ 
     ConnectivityManager connectivity = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); 
     if (connectivity != null) 
     { 
      NetworkInfo[] info = connectivity.getAllNetworkInfo(); 
      if (info != null) 
       for (int i = 0; i < info.length; i++) 
        if (info[i].getState() == NetworkInfo.State.CONNECTED) 
        { 
         return true; 
        } 

     } 
     return false; 
    } 
}