为什么我的所有 EditText.getText().toString() 都返回一个空字符串？

Question

This problem occurs throughout the app but I am only posting my register activity.

Here is a screenshot of my register activity:

Here is the xml for my register activity. I don't think you need to read it.

    <?xml version="1.0" encoding="utf-8"?>
    <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#6633ff"
        tools:context=".RegisterActivity">

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/left_guideline_edit_text"
            app:layout_constraintGuide_percent=".12077"
            android:orientation="vertical"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/right_guideline_edit_text"
            app:layout_constraintGuide_percent=".87923"
            android:orientation="vertical"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/top_guideline_edit_text_name"
            app:layout_constraintGuide_percent=".09821"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/bottom_guideline_edit_text_name"
            app:layout_constraintGuide_percent=".17857"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/top_guideline_edit_text_email"
            app:layout_constraintGuide_percent=".21429"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/bottom_guideline_edit_text_email"
            app:layout_constraintGuide_percent=".29464"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/top_guideline_edit_text_password"
            app:layout_constraintGuide_percent=".33036"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/bottom_guideline_edit_text_password"
            app:layout_constraintGuide_percent=".41071"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/top_guideline_edit_text_city"
            app:layout_constraintGuide_percent=".44420"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/bottom_guideline_edit_text_city"
            app:layout_constraintGuide_percent=".52455"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/top_guideline_edit_text_country"
            app:layout_constraintGuide_percent=".56027"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/left_guideline_register_button"
            app:layout_constraintGuide_percent=".27536"
            android:orientation="vertical"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/right_guideline_register_button"
            app:layout_constraintGuide_percent=".72222"
            android:orientation="vertical"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/top_guideline_register_button"
            app:layout_constraintGuide_percent=".70313"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/bottom_guideline_edit_text_country"
            app:layout_constraintGuide_percent=".64063"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/bottom_guideline_register_button"
            app:layout_constraintGuide_percent=".78125"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/top_guideline_edit_text_view_already_account"
            app:layout_constraintGuide_percent=".80692"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/bottom_guideline_text_view_already_account"
            app:layout_constraintGuide_percent=".84933"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/top_guideline_text_view_log_in"
            app:layout_constraintGuide_percent=".84933"
            android:orientation="horizontal"/>

        <androidx.constraintlayout.widget.Guideline
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/bottom_guideline_text_view_log_in"
            app:layout_constraintGuide_percent=".89174"
            android:orientation="horizontal"/>

        <EditText
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="@drawable/edit_text_shape"
            android:id="@+id/edit_text_name"
            android:hint="Name"
            android:textColorHint="#bbbbbb"
            android:textColor="#000000"
            android:textSize="20sp"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            android:inputType="textCapSentences"
            android:maxLines="1"
            android:imeOptions="actionNext"
            app:layout_constraintLeft_toLeftOf="@+id/left_guideline_edit_text"
            app:layout_constraintRight_toRightOf="@+id/right_guideline_edit_text"
            app:layout_constraintTop_toTopOf="@+id/top_guideline_edit_text_name"
            app:layout_constraintBottom_toBottomOf="@+id/bottom_guideline_edit_text_name"/>

        <EditText
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="@drawable/edit_text_shape"
            android:id="@+id/edit_text_email"
            android:hint="Email"
            android:textColorHint="#bbbbbb"
            android:textColor="#000000"
            android:textSize="20sp"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            android:inputType="textEmailAddress"
            android:maxLines="1"
            android:imeOptions="actionNext"
            app:layout_constraintLeft_toLeftOf="@+id/left_guideline_edit_text"
            app:layout_constraintRight_toRightOf="@+id/right_guideline_edit_text"
            app:layout_constraintTop_toTopOf="@+id/top_guideline_edit_text_email"
            app:layout_constraintBottom_toBottomOf="@+id/bottom_guideline_edit_text_email" />

        <EditText
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="@drawable/edit_text_shape"
            android:id="@+id/edit_text_password"
            android:hint="Password"
            android:textColorHint="#bbbbbb"
            android:textColor="#000000"
            android:textSize="20sp"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            android:inputType="textPassword"
            android:maxLines="1"
            android:imeOptions="actionNext"
            app:layout_constraintLeft_toLeftOf="@+id/left_guideline_edit_text"
            app:layout_constraintRight_toRightOf="@+id/right_guideline_edit_text"
            app:layout_constraintTop_toTopOf="@+id/top_guideline_edit_text_password"
            app:layout_constraintBottom_toBottomOf="@+id/bottom_guideline_edit_text_password" />

        <EditText
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="@drawable/edit_text_shape"
            android:id="@+id/edit_text_city"
            android:hint="City"
            android:textColorHint="#bbbbbb"
            android:textColor="#000000"
            android:textSize="20sp"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            android:inputType="textCapSentences"
            android:maxLines="1"
            android:imeOptions="actionNext"
            app:layout_constraintLeft_toLeftOf="@+id/left_guideline_edit_text"
            app:layout_constraintRight_toRightOf="@+id/right_guideline_edit_text"
            app:layout_constraintTop_toTopOf="@+id/top_guideline_edit_text_city"
            app:layout_constraintBottom_toBottomOf="@+id/bottom_guideline_edit_text_city" />

        <EditText
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="@drawable/edit_text_shape"
            android:id="@+id/edit_text_country"
            android:hint="Country"
            android:textColorHint="#bbbbbb"
            android:textColor="#000000"
            android:textSize="20sp"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            android:inputType="textCapSentences"
            android:maxLines="1"
            android:imeOptions="actionNext"
            app:layout_constraintLeft_toLeftOf="@+id/left_guideline_edit_text"
            app:layout_constraintRight_toRightOf="@+id/right_guideline_edit_text"
            app:layout_constraintTop_toTopOf="@+id/top_guideline_edit_text_country"
            app:layout_constraintBottom_toBottomOf="@+id/bottom_guideline_edit_text_country"/>

        <Button
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:id="@+id/register_button"
            android:background="@drawable/button_shape"
            android:fontFamily="@font/inter_extrabold"
            android:textSize="28sp"
            android:text="Register"
            android:textAlignment="center"
            android:textAllCaps="false"
            android:textColor="#6633ff"
            app:layout_constraintLeft_toLeftOf="@+id/left_guideline_register_button"
            app:layout_constraintRight_toRightOf="@+id/right_guideline_register_button"
            app:layout_constraintTop_toTopOf="@+id/top_guideline_register_button"
            app:layout_constraintBottom_toBottomOf="@+id/bottom_guideline_register_button"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/text_view_already_account"
            android:text="Already have an account?"
            android:fontFamily="@font/inter_thin"
            android:textSize="20sp"
            android:textColor="#ffffff"
            android:textAlignment="center"
            android:textAllCaps="false"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="@+id/top_guideline_edit_text_view_already_account"
            app:layout_constraintBottom_toBottomOf="@+id/bottom_guideline_text_view_already_account"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/text_view_log_in"
            android:text="@string/LogIn"
            android:fontFamily="@font/inter_semibold"
            android:textSize="28sp"
            android:textColor="#ffffff"
            android:textAlignment="center"
            android:textAllCaps="false"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="@+id/top_guideline_text_view_log_in"
            app:layout_constraintBottom_toBottomOf="@+id/bottom_guideline_text_view_log_in"/>

    </androidx.constraintlayout.widget.ConstraintLayout>

And here is my code for the activity. The main part of the code is at the bottom in the goToRegisterAs() method.

    package com.example.treeapp;

    import androidx.appcompat.app.AppCompatActivity;

    import android.content.Intent;
    import android.os.Bundle;
    import android.view.KeyEvent;
    import android.view.View;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.TextView;

    public class RegisterActivity extends AppCompatActivity {
        private EditText nameEditText;
        private EditText emailEditText;
        private EditText passwordEditText;
        private EditText cityEditText;
        private EditText countryEditText;
        private Button registerButton;
        private TextView alreadyAccountTextView;
        private TextView logInTextView;
        private String name;
        private String email;
        private String password;
        private String city;
        private String country;

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

            nameEditText = findViewById(R.id.edit_text_name);
            emailEditText = findViewById(R.id.edit_text_email);
            passwordEditText = findViewById(R.id.edit_text_password);
            cityEditText = findViewById(R.id.edit_text_city);
            countryEditText = findViewById(R.id.edit_text_country);
            registerButton = findViewById(R.id.register_button);
            alreadyAccountTextView = findViewById(R.id.text_view_already_account);
            logInTextView = findViewById(R.id.text_view_log_in);

            name = nameEditText.getText().toString();
            email = emailEditText.getText().toString();
            password = passwordEditText.getText().toString();
            city = cityEditText.getText().toString();
            country = countryEditText.getText().toString();

            registerButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    goToRegisterAs(view);
                }
            });

            countryEditText.setOnKeyListener(new View.OnKeyListener() {
                @Override
                public boolean onKey(View view, int i, KeyEvent keyEvent) {
                    if (keyEvent.getAction() == KeyEvent.ACTION_DOWN && i == KeyEvent.KEYCODE_ENTER) {
                        goToRegisterAs(view);
                        return true;
                    } else {
                        return false;
                    }
                }
            });

            logInTextView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Intent intent = new Intent(view.getContext(), MainActivity.class);

                    view.getContext().startActivity(intent);
                }
            });
        }

        void goToRegisterAs(View view) {
            if (!(name.equals("") || email.equals("") || password.equals("") ||
                city.equals("") || country.equals(""))) {
                if (email.contains("@") && email.contains(".")) {
                    if (MainActivity.database.donorsDao().checkEmail(email) == 0 &&
                        MainActivity.database.plantersDao().checkEmail(email) == 0) {
                        Intent intent = new Intent(view.getContext(), RegisterAsActivity.class);
                        intent.putExtra("name", name);
                        intent.putExtra("email", email);
                        intent.putExtra("password", password);
                        intent.putExtra("city", city);
                        intent.putExtra("country", country);

                        view.getContext().startActivity(intent);
                    } else {
                        alreadyAccountTextView.setText("Already registered. Please log in.");
                    }
                } else {
                    alreadyAccountTextView.setText("Please enter correct email address.");
                }
            } else {
                alreadyAccountTextView.setText("Please enter all fields");
                alreadyAccountTextView.setText(name + " " + email + " " + password + " " + city + " " + country);
            }
        }
    }

The app was not working as I wanted it to. So after some trying, I figured out that my EditTexts are all returning an empty string. In the last line in the code alreadyAccountTextView.setText(name + " " + email + " " + password + " " + city + " " + country) , the alreadyAccountTextView becomes empty. I wrote this line here because this block of code was being executed even though I had input text in every field. I have read many questions and answers on StackOverflow about getting text from EditTexts and all of them say that I should use EditText.getText().toString(). But it isn't working for me, due to some reason.

Answer 1

The problem is you initialise your Strings in your OnCreate function. This function is called only once, when your activity starts; therefore, at this point your EditTexts are all empty without any text in it.

To get the current text located in your EditTexts, you should move your initialisations in your goToRegisterAs() function.

    void goToRegisterAs(View view) {
            name = nameEditText.getText().toString();
            email = emailEditText.getText().toString();
            password = passwordEditText.getText().toString();
            city = cityEditText.getText().toString();
            country = countryEditText.getText().toString();
                if (!(name.equals("") || email.equals("") || password.equals("") ||
                    city.equals("") || country.equals(""))) {
                    if (email.contains("@") && email.contains(".")) {
                        if (MainActivity.database.donorsDao().checkEmail(email) == 0 &&
                            MainActivity.database.plantersDao().checkEmail(email) == 0) {
                            Intent intent = new Intent(view.getContext(), RegisterAsActivity.class);
                            intent.putExtra("name", name);
                            intent.putExtra("email", email);
                            intent.putExtra("password", password);
                            intent.putExtra("city", city);
                            intent.putExtra("country", country);
    
                            view.getContext().startActivity(intent);
                        } else {
                            alreadyAccountTextView.setText("Already registered. Please log in.");
                        }
                    } else {
                        alreadyAccountTextView.setText("Please enter correct email address.");
                    }
                } else {
                    alreadyAccountTextView.setText("Please enter all fields");
                    alreadyAccountTextView.setText(name + " " + email + " " + password + " " + city + " " + country);
                }
            }