警报不会出现

Question

在活动构建期间满足某些条件时，将调用以下方法。我遇到的问题是虽然吐司确实出现，但警报仍然没有显示。我可以想到两个原因。我的警报构造不正确或UI未更新，因为UI事件不会触发警报创建。问题是什么？有没有什么方法可以在没有UI事件的情况下显示警报对话框？

private void displayAlertToRestorePreviousValues(final Map<String, String> values) {        
        Toast.makeText(getApplicationContext(), "begin building alert", Toast.LENGTH_LONG).show();
        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
        alertDialogBuilder.setTitle("Load Previous Values");
        alertDialogBuilder
        .setMessage("Click OK to load previous values")
        .setCancelable(false)
        .setPositiveButton("OK", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int id) {

                if (values != null) {
                    if (values.get("name") != null) {
                        nameField.setText(values.get("name"));
                    }
                    if (values.get("username") != null) {
                        usernameField.setText(values.get("username"));
                    }
                    if (values.get("email") != null) {
                        emailField.setText(values.get("email"));                    
                    }

                } else {
                    if (prevIntent.hasExtra("name")) {
                        nameField.setText(prevIntent.getStringExtra("name"));
                    }
                    if (prevIntent.hasExtra("username")) {
                        usernameField.setText(prevIntent.getStringExtra("username"));
                    }
                    if (prevIntent.hasExtra("email")) {
                        emailField.setText(prevIntent.getStringExtra("email"));
                    }
                }
            }
          });
        AlertDialog alertDialog = alertDialogBuilder.create();
        alertDialog.show();
        Toast.makeText(getApplicationContext(), "end building alert", Toast.LENGTH_LONG).show();
}

修改

我在下面发布我的完整活动代码。

public class RegistrationActivity extends Activity {

    private Typeface winInnwa;
    private Typeface english;

    private TextView registrationText;

    private TextView nameText;
    private EditText nameField;
    private TextView usernameText;
    private EditText usernameField;
    private TextView emailText;
    private EditText emailField;
    private TextView confirmText;
    private EditText confirmField;

    private Button next;
    private TextView error;

    private TextView regWarning;
    private TextView termsConditions;
    private RelativeLayout warnTerms;

    private boolean nameTouched;
    private boolean usernameTouched;
    private boolean emailTouched;
    private boolean confirmEmailTouched;

    private boolean slidedDown;
    private boolean isAtPage2;
    private boolean testedForPreviousValues;    

    private Intent prevIntent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_registration);

        prevIntent = getIntent();
        if (prevIntent.hasExtra("isAtPage2"))
            isAtPage2 = prevIntent.getBooleanExtra("isAtPage2", true);

        if (isAtPage2) {
            Intent intent = new Intent(this, Registration2Activity.class);
            startActivity(intent);
        }

        winInnwa = Typeface.createFromAsset(getAssets(), "fonts/WINNWAB.ttf");
        english = Typeface.createFromAsset(getAssets(), "fonts/ARIAL_0.TTF");

        registrationText = (TextView) findViewById(R.id.registration_text);
        registrationText.setTypeface(english);

        nameText = (TextView) findViewById(R.id.name_txt_reg);
        nameText.setTypeface(english);

        nameField = (EditText) findViewById(R.id.name_fld_reg);
        nameField.setTypeface(english);
        nameField.setOnFocusChangeListener(new NameFocusChangeListener());
        nameField.setOnTouchListener(new NameTouchListener());

        usernameText = (TextView) findViewById(R.id.username_txt_reg);
        usernameText.setTypeface(english);

        usernameField = (EditText) findViewById(R.id.username_fld_reg);
        usernameField.setTypeface(english);
        usernameField
                .setOnFocusChangeListener(new UsernameFocusChangeListener());
        usernameField.setOnTouchListener(new UsernameTouchListener());

        emailText = (TextView) findViewById(R.id.email_txt_reg);
        emailText.setTypeface(english);

        emailField = (EditText) findViewById(R.id.email_fld_reg);
        emailField.setTypeface(english);
        emailField.setOnFocusChangeListener(new EmailFocusChangeListener());
        emailField.setOnTouchListener(new EmailTouchListener());

        confirmText = (TextView) findViewById(R.id.re_enter_txt_reg);
        confirmText.setTypeface(english);

        confirmField = (EditText) findViewById(R.id.re_enter_fld_reg);
        confirmField.setTypeface(english);
        confirmField
                .setOnFocusChangeListener(new ConfirmEmailFocusChangeListener());
        confirmField.setOnTouchListener(new ConfirmEmailTouchListener());

        next = (Button) findViewById(R.id.next_btn);
        next.setTypeface(english);
        next.setOnClickListener(new OnNextHandler());

        error = (TextView) findViewById(R.id.error_messages);
        error.setTypeface(english);

        regWarning = (TextView) findViewById(R.id.reg_warning_txt);
        regWarning.setTypeface(winInnwa);

        termsConditions = (TextView) findViewById(R.id.terms_and_conditions_txt);
        termsConditions.setTypeface(english);
        SpannableString spannableStringAboutInnoLuck = new SpannableString(
                getResources().getString(R.string.terms_and_conditions));
        spannableStringAboutInnoLuck.setSpan(
                new TermsConditionsClickableSpan(), 0,
                spannableStringAboutInnoLuck.length(),
                Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        spannableStringAboutInnoLuck.setSpan(new ForegroundColorSpan(
                getResources().getColor(R.color.terms_and_conditions_yellow)),
                0, spannableStringAboutInnoLuck.length(),
                Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        termsConditions.setText(spannableStringAboutInnoLuck);
        termsConditions.setMovementMethod(LinkMovementMethod.getInstance());

        warnTerms = (RelativeLayout) findViewById(R.id.warning_terms_conditions);

        testForPreviousValues(savedInstanceState);
    }

    private void testForPreviousValues(Bundle savedInstanceState) {
        Toast.makeText(getApplicationContext(), "testing", Toast.LENGTH_LONG).show();
        if (!testedForPreviousValues) {

            if (savedInstanceState != null) {

                Map<String, String> values = new HashMap<String, String>();
                boolean restorationNeeded = false;

                if (savedInstanceState.getString("name") != null) {                 
                    values.put("name", savedInstanceState.getString("name"));
                    restorationNeeded = true;                   
                }
                if (savedInstanceState.getString("username") != null) {
                    values.put("username", savedInstanceState.getString("username"));
                    restorationNeeded = true;
                }
                if (savedInstanceState.getString("email") != null) {
                    values.put("email", savedInstanceState.getString("email"));
                    restorationNeeded = true;
                }

                if (restorationNeeded) {
                    displayAlertToRestorePreviousValues(values);
                }

            } else {
                boolean retainingNeeded = false;
                if (prevIntent.hasExtra("name")) {      
                    retainingNeeded = true;
                }
                if (prevIntent.hasExtra("username")) {
                    retainingNeeded = true;
                }
                if (prevIntent.hasExtra("email")) {
                    retainingNeeded = true;                 
                }
                if (retainingNeeded) {
                    displayAlertToRestorePreviousValues();
                }
            }
        }

        testedForPreviousValues = true;
    }

    private void displayAlertToRestorePreviousValues(final Map<String, String> values) {        
        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
        alertDialogBuilder.setTitle("Load Previous Values");
        alertDialogBuilder.setMessage("Click OK to load previous values");
        alertDialogBuilder.setCancelable(false);
        alertDialogBuilder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int id) {
                dialog.dismiss();
                if (values != null) {
                    if (values.get("name") != null) {
                        nameField.setText(values.get("name"));
                    }
                    if (values.get("username") != null) {
                        usernameField.setText(values.get("username"));
                    }
                    if (values.get("email") != null) {
                        emailField.setText(values.get("email"));                    
                    }

                } else {
                    if (prevIntent.hasExtra("name")) {
                        nameField.setText(prevIntent.getStringExtra("name"));
                    }
                    if (prevIntent.hasExtra("username")) {
                        usernameField.setText(prevIntent.getStringExtra("username"));
                    }
                    if (prevIntent.hasExtra("email")) {
                        emailField.setText(prevIntent.getStringExtra("email"));
                    }
                }
            }
          });
        alertDialogBuilder.create();
        alertDialogBuilder.show();
    }

    private void displayAlertToRestorePreviousValues() {        
        displayAlertToRestorePreviousValues(null);
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        if (nameField.getText().toString().trim().equals("your real name")
                || nameField.getText().toString().trim().equals("")) {
        } else if (usernameField.getText().toString().trim()
                .equals("innoLUCK username")
                || usernameField.getText().toString().trim().equals("")) {
        } else if (!emailField.getText().toString().trim()
                .equals("your email address")
                && !Utils.isEmailValid(emailField.getText().toString())) {
        } else if (!emailField.getText().toString().trim()
                .equals("your email address")
                && !confirmField.getText().toString().trim()
                        .equals("confirm email address")
                && !emailField.getText().toString().trim()
                        .equals(confirmField.getText().toString().trim())) {
        } else {
            outState.putString("name", nameField.getText().toString().trim());
            outState.putString("username", usernameField.getText().toString()
                    .trim());
            if (!usernameField.getText().toString().trim()
                    .equals("your email address"))
                outState.putString("email", emailField.getText().toString()
                        .trim());
        }
        super.onSaveInstanceState(outState);
    }

    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {      
        testForPreviousValues(savedInstanceState);
        super.onRestoreInstanceState(savedInstanceState);
    }

    private void notifyError(String message) {
        if (!slidedDown) {
            Animation animSlideDown = AnimationUtils.loadAnimation(
                    getApplicationContext(), R.anim.slide_down_ten);
            animSlideDown
                    .setAnimationListener(new SlideDownAnimationListener());
            warnTerms.startAnimation(animSlideDown);
        }
        error.setText("* " + message);
        error.setVisibility(View.VISIBLE);

        slidedDown = true;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.registration, menu);
        return true;
    }

    private class SlideDownAnimationListener implements AnimationListener {

        @Override
        public void onAnimationEnd(Animation animation) {
            warnTerms
                    .setTranslationY(10 * getResources().getDisplayMetrics().density);

        }

        @Override
        public void onAnimationRepeat(Animation animation) {

        }

        @Override
        public void onAnimationStart(Animation animation) {

        }

    }

    private class OnNextHandler implements View.OnClickListener {

        @Override
        public void onClick(View v) {

            if (nameField.getText().toString().trim().equals("your real name")
                    || nameField.getText().toString().trim().equals("")) {
                notifyError("name cannot be blank");
            } else if (usernameField.getText().toString().trim()
                    .equals("innoLUCK username")
                    || usernameField.getText().toString().trim().equals("")) {
                notifyError("username cannot be blank");
            } else if (!emailField.getText().toString().trim()
                    .equals("your email address")
                    && !Utils.isEmailValid(emailField.getText().toString())) {
                notifyError("invalid email");
            } else if (!emailField.getText().toString().trim()
                    .equals("your email address")
                    && !confirmField.getText().toString().trim()
                            .equals("confirm email address")
                    && !emailField.getText().toString().trim()
                            .equals(confirmField.getText().toString().trim())) {
                notifyError("emails do not match");
            } else {

                Intent intent = new Intent(RegistrationActivity.this,
                        Registration2Activity.class);
                intent.putExtra("name", nameField.getText().toString().trim());
                intent.putExtra("username", usernameField.getText().toString()
                        .trim());
                if (!emailField.getText().toString().trim()
                        .equals("your email address"))
                    intent.putExtra("email", emailField.getText().toString()
                            .trim());
                isAtPage2 = true;
                startActivity(intent);
            }
        }
    }

    private class TermsConditionsClickableSpan extends ClickableSpan {

        @Override
        public void onClick(View widget) {

            Intent intent = new Intent(RegistrationActivity.this,
                    TermsConditionsActivity.class);

            if (prevIntent.hasExtra("name"))
                intent.putExtra("name", prevIntent.getStringExtra("name"));
            if (prevIntent.hasExtra("username"))
                intent.putExtra("username",
                        prevIntent.getStringExtra("username"));
            if (prevIntent.hasExtra("email"))
                intent.putExtra("email", prevIntent.getStringExtra("email"));

            if (nameField.getText().toString().trim().equals("your real name")
                    || nameField.getText().toString().trim().equals("")) {
                intent.putExtra("name", nameField.getText().toString().trim());
            }

            if (usernameField.getText().toString().trim()
                    .equals("innoLUCK username")
                    || usernameField.getText().toString().trim().equals("")) {
                intent.putExtra("username", usernameField.getText().toString()
                        .trim());
            }

            if (!emailField.getText().toString().trim()
                    .equals("your email address")
                    && !Utils.isEmailValid(emailField.getText().toString())) {
            } else if (!emailField.getText().toString().trim()
                    .equals("your email address")
                    && !confirmField.getText().toString().trim()
                            .equals("confirm email address")
                    && !emailField.getText().toString().trim()
                            .equals(confirmField.getText().toString().trim())) {
            } else {
                intent.putExtra("email", emailField.getText().toString().trim());
            }
            intent.putExtra("isAtPage2", false);
            startActivity(intent);
        }

    }

    private class ConfirmEmailFocusChangeListener implements
            OnFocusChangeListener {
        @Override
        public void onFocusChange(View v, boolean hasFocus) {
            if (hasFocus) {
                if (confirmField.getText().toString().trim()
                        .equals("confirm email address")
                        && confirmEmailTouched) {
                    confirmField.setText("");
                }
            } else {
                if (confirmField.getText().toString().trim().equals("")) {
                    confirmField.setText("confirm email address");
                }
            }
        }
    }

    private class ConfirmEmailTouchListener implements OnTouchListener {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            confirmEmailTouched = true;
            if (confirmField.getText().toString().trim()
                    .equals("confirm email address")) {
                confirmField.setText("");
            }
            return false;
        }

    }

    private class EmailFocusChangeListener implements OnFocusChangeListener {
        @Override
        public void onFocusChange(View v, boolean hasFocus) {
            if (hasFocus) {
                if (emailField.getText().toString().trim()
                        .equals("your email address")
                        && emailTouched) {
                    emailField.setText("");
                }
            } else {
                if (emailField.getText().toString().trim().equals("")) {
                    emailField.setText("your email address");
                }
            }
        }
    }

    private class EmailTouchListener implements OnTouchListener {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            emailTouched = true;
            if (emailField.getText().toString().trim()
                    .equals("your email address")) {
                emailField.setText("");
            }
            return false;
        }

    }

    private class UsernameFocusChangeListener implements OnFocusChangeListener {
        @Override
        public void onFocusChange(View v, boolean hasFocus) {
            if (hasFocus) {
                if (usernameField.getText().toString().trim()
                        .equals("innoLUCK username")
                        && usernameTouched) {
                    usernameField.setText("");
                }
            } else {
                if (usernameField.getText().toString().trim().equals("")) {
                    usernameField.setText("innoLUCK username");
                }
            }
        }
    }

    private class UsernameTouchListener implements OnTouchListener {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            usernameTouched = true;
            if (usernameField.getText().toString().trim()
                    .equals("innoLUCK username")) {
                usernameField.setText("");
            }
            return false;
        }

    }

    private class NameFocusChangeListener implements OnFocusChangeListener {
        @Override
        public void onFocusChange(View v, boolean hasFocus) {
            if (hasFocus) {
                if (nameField.getText().toString().trim()
                        .equals("your real name")
                        && nameTouched) {
                    nameField.setText("");
                }
            } else {
                if (nameField.getText().toString().trim().equals("")) {
                    nameField.setText("your real name");
                } else if (nameField.getText().toString().trim()
                        .endsWith("your real name")) {
                    nameField.setText(nameField
                            .getText()
                            .toString()
                            .trim()
                            .substring(
                                    0,
                                    nameField.getText().toString().trim()
                                            .length() - 14));
                }
            }
        }
    }

    private class NameTouchListener implements OnTouchListener {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            nameTouched = true;
            if (nameField.getText().toString().trim().equals("your real name")) {
                nameField.setText("");
            }
            return false;
        }

    }

    private class LoadOldValueListener implements OnTouchListener {

        private Map<String, String> values;

        public LoadOldValueListener(Map<String, String> values) {
            values = this.values;
        }

        @Override
        public boolean onTouch(View v, MotionEvent event) {

            return false;
        }

    }   

}

Answer 1

请尝试以下代码。它对我来说很好。请尝试让我知道。感谢。

private void displayAlertToRestorePreviousValues(final Map<String, String> values) {        
    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
    alertDialogBuilder.setTitle("Load Previous Values");
    alertDialogBuilder.setMessage("Click OK to load previous values");
    alertDialogBuilder.setCancelable(false);
    alertDialogBuilder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int id) {
            dialog.dismiss();
            if (values != null) {
                if (values.get("name") != null) {
                    nameField.setText(values.get("name"));
                }
                if (values.get("username") != null) {
                    usernameField.setText(values.get("username"));
                }
                if (values.get("email") != null) {
                    emailField.setText(values.get("email"));                    
                }

            } else {
                if (prevIntent.hasExtra("name")) {
                    nameField.setText(prevIntent.getStringExtra("name"));
                }
                if (prevIntent.hasExtra("username")) {
                    usernameField.setText(prevIntent.getStringExtra("username"));
                }
                if (prevIntent.hasExtra("email")) {
                    emailField.setText(prevIntent.getStringExtra("email"));
                }
            }
        }
      });
    alertDialogBuilder.create();
    alertDialogBuilder.show();
}