Question

我为我的学校开发了一个应用程序。如果单击“登录”按钮，登录屏幕应显示ProgressDialog。它运行正常，但今天我得到了这个错误（使用Stacktrace）

  android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
        at android.view.ViewRootImpl.setView(ViewRootImpl.java:536)
        at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:259)
        at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
        at android.app.Dialog.show(Dialog.java:286)
        at de.eichsfeld.logik.LoginActivity$1LoginTask.onPreExecute(LoginActivity.java:107)
        at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:587)
        at android.os.AsyncTask.execute(AsyncTask.java:535)
        at de.eichsfeld.logik.LoginActivity$1.onClick(LoginActivity.java:193)
        at android.view.View.performClick(View.java:4438)
        at android.view.View$PerformClick.run(View.java:18422)
        at android.os.Handler.handleCallback(Handler.java:733)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5001)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
        at dalvik.system.NativeStart.main(Native Method)

我不确定这意味着什么。我谷歌一些similair问题，但新的Progressdialog（）中的getApplicationContext（）或getParent（）不适合我。

所以我希望你能帮助我！

登录异步任务的源代码：

class LoginTask extends AsyncTask< String , String , String >
        {
            int success;
            String uname;
            String password;

            @Override
            protected void onPreExecute()
            {
                super.onPreExecute();
                pDialog = new ProgressDialog(LoginActivity.this);
                pDialog.setMessage("Du wirst eingeloggt..");
                pDialog.setIndeterminate(false);
                pDialog.setCancelable(true);
                pDialog.show();
            }

            @Override
            protected String doInBackground( String ... args )
            {
                uname = inputUser.getText().toString();
                password = inputPassword.getText().toString();

                UserLoginFunctions userFunction = new UserLoginFunctions();

                // User wird eingeloggt
                JSONObject json = userFunction.loginUser(uname , password);

                Log.d("Antwort: " , json.toString());
                if (uname.trim().length() > 0
                        && password.trim().length() > 0)
                {
                    try
                    {
                        // war Login erfolgreich? wenn ja fhre
                        // weiterfhrende
                        // Funktionen nach dem Login aus
                        success = json.getInt(TAG_SUCCESS);

                        if (success == 1)
                        {
                            json_datenbank = json.getString(KEY_DATENBANK);
                            System.out.println(json_datenbank);
                            String json_vorname = json
                                    .getString(KEY_VORNAME);
                            String json_nachname = json
                                    .getString(KEY_NACHNAME);
                            String json_pushbenachrichtigung = json.getString(KEY_PUSHBENACHRICHTIGUNG);

                            // speicher alles in einer SharedPreferences
                            sessionmanager.erzeugeLoginSession(
                                    json_datenbank , json_nachname ,
                                    json_vorname, json_pushbenachrichtigung);
                            // fhre die registrierung aus
                            gcmRegistrierung();

                            // MainFrame anzeigen
                            Intent mainView = new Intent(
                                    getApplicationContext() ,
                                    FragmentMananger.class);
                            // Alle anderen Views werden geschlossen
                            mainView.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                            startActivity(mainView);

                            // schliesse LoginScreen
                            finish();
                        }
                    }
                    catch (JSONException e)
                    {
                        throw new RuntimeException("Daten konnten nicht geparst werden! " + e.getMessage());
                    }

                }
                return null;
            }

            protected void onPostExecute( String file_url )
            {
                // schliesse den Progress Dialog
                pDialog.dismiss();

                if (success == 0)
                {
                    // Logindaten sind falsch
                    alert.showAlertDialog(
                            LoginActivity.this ,
                            "Login fehlgeschlagen" ,
                            "Bitte Nutzername und Passwort korrekt eingeben" ,
                            false);
                }
            }
        }

Answer 1

您可以将上下文传递到异步任务：

LoginTask.class

        private Context mcontext;
        public LoginTask (Context context) {
            // TODO Auto-generated constructor stub
            this.mcontext= context;
        }

        @Override
        protected void onPreExecute()
        {
            super.onPreExecute();
            pDialog = new ProgressDialog(mcontext.getApplicationContext());
            pDialog.setMessage("Du wirst eingeloggt..");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();
        }

caller.class： -

        new LoginTask(getActivity()).execute(params..);

无法添加Window - 令牌null不适用于应用程序（异步任务）

1 个答案: