EditText getText()返回空字符串

Question

我有一个带按钮的活动,当用户点击按钮时,AlertDialog会显示2 EditText,您可以在其中输入电子邮件和密码进行登录.当我尝试从EditText获取文本时,我总是只得到空字符串.布局login_alert是AlertDialog的布局.这里的代码:

    View view = getLayoutInflater().inflate(R.layout.login_alert, null, false);
    String email = ((EditText) view.findViewById(R.id.emailEditText)).getText().toString();
    String password = ((EditText) view.findViewById(R.id.passwordEditText)).getText().toString();

    System.out.println("DEBUG: "+email+", "+password); // Empty strings

编辑: 活动代码:

    public class MainActivity extends FragmentActivity {

    public static final String mAPP_ID = "...";
    public static final String USER_DB_URL = "...";

    AssetsExtracter mTask;

    private MainFragment mainFragment;
    private List<User> usersList = new ArrayList<User>();
    private User currentUser = null;

    private Button labLoginButton;
    private EditText emailET;
    private EditText passwordET;

    private ProgressDialog dialog;
    private View alertView; /* THIS IS THE SOLUTION */

    boolean userIsLogged = false;

    static {
        IMetaioSDKAndroid.loadNativeLibs();
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

        setContentView(R.layout.activity_main);

        /*View view = getLayoutInflater().inflate(R.layout.login_alert, null, false); BEFORE*/
            alertView = getLayoutInflater().inflate(R.layout.login_alert, null, false);
        emailET = (EditText) view.findViewById(R.id.emailEditText);
        passwordET = (EditText) view.findViewById(R.id.passwordEditText);

        labLoginButton = (Button) findViewById(R.id.loginLabButton);
        updateLoginButton();

        dialog = new ProgressDialog(this);
        dialog.setMessage("Signin in...");

        if (savedInstanceState == null) {
            // Add the fragment on initial activity setup
            mainFragment = new MainFragment();
            getSupportFragmentManager().beginTransaction()
                    .add(android.R.id.content, mainFragment).commit();
        } else {
            // Or set the fragment from restored state info
            mainFragment = (MainFragment) getSupportFragmentManager()
                    .findFragmentById(android.R.id.content);
        }

        mTask = new AssetsExtracter();
        mTask.execute(0);

    }

    /* THIS METHOD IS CALLED BY THE LOGIN BUTTON IN THE MAIN ACTIVITY LAYOUT */
    public void onLabLoginButtonClick(View v) {
        if (userIsLogged) {
            currentUser = null;
            userIsLogged = false;
            updateLoginButton();
            Toast.makeText(this, "Disconnected from Lab", Toast.LENGTH_SHORT)
                    .show();
        } else {
            /*View messageView = getLayoutInflater().inflate(
                    R.layout.login_alert, null, false); BEFORE */

            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setIcon(R.drawable.icon_launcher);
            builder.setTitle(R.string.login_string);
            builder.setView(alertView); /* USING THE GLOBAL VARIABLE */
            builder.setPositiveButton("Sign me", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface d, int which) {
                    dialog.show();

                    // Download user and return a List of User
                    DownloadFilesAsyncTask task = new DownloadFilesAsyncTask(USER_DB_URL) {
                        @Override
                        protected void onPostExecute(final List<User> result) {
                            usersList = result;
                            loginCheckRoutine(); //HERE I MANAGE THE LOGIN AND GETTING EMPTY STRING
                        }
                    };
                    task.execute();
                }
            });
            builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {
                    // TODO Auto-generated method stub

                }
            });
            builder.create();
            builder.show();
        }
    }

    public void updateLoginButton() {
        if (userIsLogged) {
            labLoginButton.setText(R.string.logout_string);
        } else {
            labLoginButton.setText(R.string.login_string);
        }
    }

    public void loginCheckRoutine() {


        String email = emailET.getText().toString();
        String password = passwordET.getText().toString();

        System.out.println("DEBUG: " + email + ", " + password); // EMPTY

        // controllo nella lista se c'è l'utente coi dati inseriti
        for (int i = 0; i < usersList.size(); i++) {
            if (usersList.get(i).getEmail().equals(email)
                    && password.equals("admin")) {
                currentUser = usersList.get(i);
                userIsLogged = true;
                updateLoginButton();
                dialog.dismiss();
                break;
            }
        }
        if (!userIsLogged) {
            userIsLogged = false;
            updateLoginButton();
            dialog.dismiss();
            Toast.makeText(MainActivity.this, "Login Failed",
                    Toast.LENGTH_SHORT).show();
        }
    }

}

问题已解决,解决方案: 在onCreate()中,我在View变量中膨胀alert_dialog布局.我将View变量设置为global(在onCreate()之前),然后在onLabLoginButtonClick()中我不再对视图进行充气,但是我在onCreate()中使用了全局实例化.希望它清楚.谢谢你们!

Answer 1

你getText 刚刚初始化.直到您在xml中有文本,您将无法获得文本.在onclick的alertdialog按钮获取文本.

宣布

EdiText ed1,ed2; // before onCreate if in activity and onCraeteView in fragment

作为实例变量

View view = getLayoutInflater().inflate(R.layout.login_alert, null, false);
ed1= (EditText) view.findViewById(R.id.emailEditText))
ed2 = (EditText) view.findViewById(R.id.emailEditText);

然后在Alert对话框上单击按钮

  String email = ed1.getText().toString();
  String password= ed2.getText().toString()

Answer 2

单击警告对话框的登录按钮时必须获取文本

上面提到的代码，当您显示警报对话框时，您会收到文本，它始终返回始终为空的字符串，您应该先按照以下步骤进行操作，然后创建一个自定义警报框布局，其中包含两个编辑文本和一个按钮，用户将文本写入编辑文本以进行登录并提供密码和然后在调用登录按钮单击侦听器时单击登录按钮，您可以轻松获取编辑文本的文本