AlertDialog的java.lang.NullPointerException（Android）

Question

I am trying to implement Parse Cloud Backend for password resets. I am running into an NullPointerException when I try to get the value out of an editTextField from within an AlertDialog.

The AlertDialog can be found inside the textViewForgotPassword case inside the OnClick(). any ideas what I am missing?

public class MainActivity extends Activity implements OnClickListener {

private static final String TAG = "OwlSample";

EditText etSignInUsername;
EditText etSignInPassword;
EditText etForgotPassword;
TextView tvForgotPassword;

private Dialog progressDialog;
private AlertDialog passwordDialog;

Context context;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

    context = this;

    // sign in button
    findViewById(R.id.sign_in_button).setOnClickListener(this);
    findViewById(R.id.sign_up_button).setOnClickListener(this);

    // edittexts
    etSignInUsername = (EditText) findViewById(R.id.editTextSignInUsername);
    etSignInPassword = (EditText) findViewById(R.id.editTextSignInPassword);
    etForgotPassword = (EditText) findViewById(R.id.editTextForgotPassword);
    tvForgotPassword = (TextView) findViewById(R.id.textViewForgotPassword);

    tvForgotPassword.setOnClickListener(this);

    // Check if there is a currently logged in user
    // and they are linked to a Facebook account.
    final ParseUser currentUser = ParseUser.getCurrentUser();
    if ((currentUser != null)) {

        // you can add this line &&
        // ParseFacebookUtils.isLinked(currentUser)) to if statement
        // if you want to make sure the user is also linked to facebook
        // account
        // Go to the user info activity
        showPrimaryActivity();
    }

}

@Override
protected void onResume() {
    super.onResume();
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    ParseFacebookUtils.finishAuthentication(requestCode, resultCode, data);
}

private void showPrimaryActivity() {
    Intent intent = new Intent(context, NaviActivity.class);
    startActivity(intent);
    finish();
}

private void resetPassword(String email) {

    ParseUser.requestPasswordResetInBackground(email,
            new RequestPasswordResetCallback() {
                public void done(ParseException e) {
                    if (e == null) {
                        // An email was successfully sent with reset
                        // instructions.
                    } else {
                        // Something went wrong. Look at the ParseException
                        // to see what's up.
                        Log.e("PARSE EXCEPTION:", "PARSE CAUSE:", e.getCause());
                    }
                }
            });

}

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub
    switch (v.getId()) {
    case R.id.sign_in_button:
        Log.e(TAG, "Tapped sign in");

        String username = etSignInUsername.getText().toString()
                .toLowerCase().trim();
        String password = etSignInPassword.getText().toString().trim();

        try {
            if (username.isEmpty() || password.isEmpty()) {
                if (username.isEmpty()) {
                    etSignInUsername.setHintTextColor(getResources()
                            .getColor(R.color.red));
                    etSignInUsername.setHint("Enter Username");
                }
                if (password.isEmpty()) {
                    etSignInPassword.setHintTextColor(getResources()
                            .getColor(R.color.red));
                    etSignInPassword.setHint("Enter Password");
                }

            }
        } finally {
            if (!username.isEmpty() || !password.isEmpty()) {
                ParseUser.logInInBackground(username, password,
                        new LogInCallback() {
                            public void done(ParseUser user,
                                    ParseException e) {
                                if (user != null) {
                                    showPrimaryActivity();
                                    // Hooray! The user is logged in.
                                } else {

                                    etSignInUsername.getText().clear();
                                    etSignInUsername
                                            .setHintTextColor(getResources()
                                                    .getColor(R.color.red));
                                    etSignInUsername
                                            .setHint("Invalid Username or Pass");

                                    etSignInPassword.getText().clear();
                                    etSignInPassword
                                            .setHintTextColor(getResources()
                                                    .getColor(R.color.red));
                                    etSignInPassword
                                            .setHint("Invalid Username or Pass");
                                    Log.e("LOGIN FAILED",
                                            "FAILED TO LOG IN");
                                    // Signup failed. Look at the
                                    // ParseException to see what happened.
                                }
                            }
                        });
            }

        }
        break;

    case R.id.sign_up_button:
        Intent intent1 = new Intent(this, SignUpActivity.class);
        startActivity(intent1);
        Log.e(TAG, "Tapped sign up");
        break;

    case R.id.textViewForgotPassword:
        Log.e(TAG, "Tapped forgot password");
        // prompt user with dialog to enter email

        LayoutInflater li = LayoutInflater.from(this);
        View dialogView = li.inflate(R.layout.forgot_password_dialog_view,
                null);

        AlertDialog.Builder builder1 = new AlertDialog.Builder(MainActivity.this);
        builder1.setView(dialogView);

        builder1.setCancelable(true);
        builder1.setPositiveButton("Yes",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {

                        String forgotPasswordEmail = etForgotPassword
                                .getText().toString().trim();
                        //resetPassword(forgotPasswordEmail);


                    }
                });
        builder1.setNegativeButton("No",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.cancel();
                    }
                });

        AlertDialog alertDialog = builder1.create();
        alertDialog.show();

        Button nButton = alertDialog
                .getButton(DialogInterface.BUTTON_NEGATIVE);
        if (nButton != null) {
            nButton.setTextSize(20);
            nButton.setTextColor(getResources().getColor(R.color.gray_35));
        }

        Button pButton = alertDialog
                .getButton(DialogInterface.BUTTON_POSITIVE);
        if (pButton != null) {
            pButton.setTextSize(20);
            pButton.setTextColor(getResources().getColor(R.color.gray_35));
        }

        break;

    }

}

}

STACKTRACE

    08-09 19:09:14.420: E/AndroidRuntime(6530): FATAL EXCEPTION: main
08-09 19:09:14.420: E/AndroidRuntime(6530): Process: com.owl.main, PID: 6530
08-09 19:09:14.420: E/AndroidRuntime(6530): java.lang.NullPointerException
08-09 19:09:14.420: E/AndroidRuntime(6530):     at com.owl.main.MainActivity$3.onClick(MainActivity.java:193)
08-09 19:09:14.420: E/AndroidRuntime(6530):     at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166)
08-09 19:09:14.420: E/AndroidRuntime(6530):     at android.os.Handler.dispatchMessage(Handler.java:102)
08-09 19:09:14.420: E/AndroidRuntime(6530):     at android.os.Looper.loop(Looper.java:136)
08-09 19:09:14.420: E/AndroidRuntime(6530):     at android.app.ActivityThread.main(ActivityThread.java:5105)
08-09 19:09:14.420: E/AndroidRuntime(6530):     at java.lang.reflect.Method.invokeNative(Native Method)
08-09 19:09:14.420: E/AndroidRuntime(6530):     at java.lang.reflect.Method.invoke(Method.java:515)
08-09 19:09:14.420: E/AndroidRuntime(6530):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792)
08-09 19:09:14.420: E/AndroidRuntime(6530):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:608)

Answer 1

Fixed:

The key is to reference/define the editText from within the view it is defined.

LayoutInflater li = LayoutInflater.from(this);
View dialogView = li.inflate(R.layout.forgot_password_dialog_view,
                    null);

etForgotPassword = (EditText) dialogView.findViewById(R.id.editTextForgotPassword);