java - 尝试调用虚拟方法 'android.text.Editable android.widget.EditText.getText()'

Question

我使用 firebase 数据库通过自定义字段注册用户。突然我得到了这个意想不到的错误。我之前没有看到这个错误。

FATAL EXCEPTION: main Process:com.example.muhammadtehmoor.testing, PID: 23770 java.lang.NullPointerException:Attempt to invoke virtual method android.text.Editable android.widget.EditText.getText()' on a null object reference com.example.muhammadtehmoor.testing SignUpActivity$1 ..onClick(SignUpActivity.java:49)

这是我的注册 Activity :

package com.example.muhammadtehmoor.testing;

import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;

public class SignUpActivity extends AppCompatActivity {

    EditText txtname,txtphone,txtemail,txtpassword;
    String fullname="",email="",phone="",password = "";
    Button submit,cancel;
    private FirebaseAuth firebaseAuth;
    private DatabaseReference databaseReference;
    private FirebaseDatabase firebaseDatabase;

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

        txtname = (EditText) findViewById(R.id.edittext2);
        txtphone = (EditText)findViewById(R.id.editText3);
        txtemail = (EditText)findViewById(R.id.editText4);
        txtpassword = (EditText)findViewById(R.id.editText5);
        submit = (Button)findViewById(R.id.btn_submit);
        cancel = (Button)findViewById(R.id.btn_cancel);

        databaseReference = FirebaseDatabase.getInstance().getReference("Driver");
        firebaseAuth = FirebaseAuth.getInstance();


        submit.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                fullname = txtname.getText().toString();
                email    = txtemail.getText().toString();
                phone    = txtphone.getText().toString();
                password = txtpassword.getText().toString();

                if(TextUtils.isEmpty(fullname))
                {
                    txtname.setError("Enter a valid credential");
                    txtname.requestFocus();
                    return;
                }

                if(TextUtils.isEmpty(email))
                {
                    txtemail.setError("Enter a valid credential");
                    txtemail.requestFocus();
                    return;
                }
                if(TextUtils.isEmpty(phone))
                {
                    txtphone.setError("Enter a valid credential");
                    txtphone.requestFocus();
                    return;
                }
                if(TextUtils.isEmpty(password))
                {
                    txtpassword.setError("Enter a valid credential");
                    txtpassword.requestFocus();
                    return;
                }
                if(password.length()<6)
                {

                    txtpassword.setError("password too short");
                    txtpassword.requestFocus();
                    return;
                }

                firebaseAuth.createUserWithEmailAndPassword(txtemail.getText().toString(), txtpassword.getText().toString())
                        .addOnCompleteListener(SignUpActivity.this, new OnCompleteListener<AuthResult>() {
                            @Override
                            public void onComplete(@NonNull Task<AuthResult> task) {

                                if (task.isSuccessful()) {

                                    Driver object = new Driver(
                                            fullname,
                                            phone,
                                            email
                                    );

                                    FirebaseDatabase.getInstance().getReference("Driver")
                                            .child(FirebaseAuth.getInstance().getCurrentUser().getUid())
                                            .setValue(object).addOnCompleteListener(new OnCompleteListener<Void>() {
                                        @Override
                                        public void onComplete(@NonNull Task<Void> task) {
                                            if (task.isSuccessful()) {

                                                // next.setVisibility(View.GONE);
                                                //back.setVisibility(View.GONE);
                                                Toast.makeText(SignUpActivity.this, "Registeration Complete", Toast.LENGTH_SHORT).show();
                                                startActivity(new Intent(SignUpActivity.this, LoginActivity.class));
                                            } else {

                                                Toast.makeText(SignUpActivity.this, "Account creation failed", Toast.LENGTH_SHORT).show();
                                            }

                                        }
                                    });

                                    //updateUserInfo(pickedImageUri,firebaseAuth.getCurrentUser());

                                } else {


                                    Toast.makeText(SignUpActivity.this, task.getException().getMessage(), Toast.LENGTH_SHORT).show();

                                }

                                // ...
                            }
                        });////firebase auth
            }
        });

        cancel.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

            }
        });


    }
}

这是我的注册 XML:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    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"
    tools:context="com.example.muhammadtehmoor.testing.SignUpActivity">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="100dp"
            android:text="Sign Up Form"
            android:textSize="35dp"
            android:gravity="center"
            android:textColor="@android:color/black"/>

        <EditText
            android:id="@+id/editText2"
            android:layout_width="match_parent"
            android:layout_height="70dp"
            android:layout_marginEnd="30dp"
            android:layout_marginStart="30dp"
            android:layout_marginTop="20dp"
            android:textSize="20dp"
            android:ems="10"
            android:inputType="textPersonName"
            android:hint="Enter your Name" />

        <EditText
            android:id="@+id/editText3"
            android:layout_width="match_parent"
            android:layout_height="70dp"
            android:layout_marginEnd="30dp"
            android:layout_marginStart="30dp"
            android:layout_marginTop="20dp"
            android:textSize="20dp"
            android:ems="10"
            android:inputType="phone"
            android:hint="Enter your phone no" />

        <EditText
            android:id="@+id/editText4"
            android:layout_width="match_parent"
            android:layout_height="70dp"
            android:layout_marginEnd="30dp"
            android:layout_marginStart="30dp"
            android:layout_marginTop="20dp"
            android:textSize="20dp"
            android:ems="10"
            android:inputType="textEmailAddress"
            android:hint="Enter your email" />
        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:passwordToggleEnabled="true"
            app:hintEnabled="true"
            app:passwordToggleDrawable="@drawable/passwordlock">

        <EditText
            android:id="@+id/editText5"
            android:layout_width="match_parent"
            android:layout_height="70dp"
            android:layout_marginEnd="30dp"
            android:layout_marginStart="30dp"
            android:layout_marginTop="20dp"
            android:textSize="20dp"
            android:ems="10"
            android:inputType="textPassword"
            android:hint="Enter your password" />
        </android.support.design.widget.TextInputLayout>


        <Button
            android:id="@+id/btn_submit"
            android:layout_width="200dp"
            android:layout_height="wrap_content"
            android:text="Submit"
            android:background="@drawable/button_design"
            android:layout_marginLeft="100dp"
            android:drawableRight="@drawable/ic_send_black_24dp"
            android:drawableTint="@color/colorPrimaryDark"
            android:paddingRight="10dp"
            android:layout_marginTop="20dp"
            android:textColor="@android:color/black"/>

        <Button
            android:id="@+id/btn_cancel"
            android:layout_width="200dp"
            android:layout_height="wrap_content"
            android:layout_marginLeft="100dp"
            android:layout_marginTop="20dp"
            android:layout_weight="1"
            android:background="@drawable/button_design"
            android:drawableRight="@drawable/ic_cancel_black_24dp"
            android:drawableTint="@color/colorPrimaryDark"
            android:paddingRight="10dp"
            android:text="Cancel"
            android:textColor="@android:color/black"
            tools:ignore="InvalidId" />



    </LinearLayout>

    </ScrollView>

</RelativeLayout>

Answer 1

请更改

txtname = (EditText) findViewById(R.id.edittext2);

至

txtname = (EditText) findViewById(R.id.editText2);

您在 XML 中使用大写 T 声明了 id，而在 java 中使用小写 t。