Question

我提供了从注册页面到添加联系人页面的意图，并在添加联系人页面中尝试使用两个功能addusers（）和addcontacts（）将详细信息添加到Firebase数据库中有人可以帮我吗

这是我的registration.java文件

package universe.sk.syndriveapp;

import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
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.auth.FirebaseUser;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;

public class RegistrationActivity extends AppCompatActivity {

    private EditText etName, etEmailsign, etPassign, etConfirmPassign, etBloodgroup, etDate;
    private Button btn_register;
    private TextView tvExist;
    private FirebaseAuth firebaseAuth;
    String name, email, password, bloodgrp, date;


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

        ActionBar actionBar = getSupportActionBar();
        actionBar.setTitle("SIGN UP");
        setupUIViews();

        firebaseAuth = FirebaseAuth.getInstance();

        btn_register.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                if (validate()) {
                    String user_email = etEmailsign.getText().toString().trim();
                    String user_password = etPassign.getText().toString().trim();

                    //store in database:to be done after filling the contacts
                    firebaseAuth.createUserWithEmailAndPassword(user_email, user_password).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
                        @Override
                        public void onComplete(@NonNull Task<AuthResult> task) {
                            if (task.isSuccessful()) {
                                finish();
                                startActivity(new Intent(RegistrationActivity.this, AddContacts.class));
                                //Toast.makeText(RegistrationActivity.this, "Registration Successful!", Toast.LENGTH_SHORT).show();
                            } else
                                Toast.makeText(RegistrationActivity.this, "Registration Failed!", Toast.LENGTH_SHORT).show();
                        }
                    });


                    //startActivity(new Intent(RegistrationActivity.this,NavigationActivity.class));
                }
            }
        });

        tvExist.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                startActivity(new Intent(RegistrationActivity.this, MainActivity.class));
            }
        });
    }


    private void setupUIViews() {
        etName = findViewById(R.id.etName);
        etEmailsign = findViewById(R.id.etEmailsign);
        etPassign = findViewById(R.id.etPassign);
        btn_register = findViewById(R.id.btn_register);
        tvExist = findViewById(R.id.tvExist);
        etConfirmPassign = findViewById(R.id.etConfirmPassign);
        etDate = (EditText) findViewById(R.id.etDate);
        etBloodgroup = (EditText) findViewById(R.id.etBloodgroup);
    }

    private Boolean validate() {
        Boolean result = false;
        bloodgrp = etBloodgroup.getText().toString().trim();
        date = etDate.getText().toString().trim();
        name = etName.getText().toString();
        password = etPassign.getText().toString();
        email = etEmailsign.getText().toString();
        String confirmpass = etConfirmPassign.getText().toString();

        if (name.isEmpty() || password.isEmpty() || email.isEmpty()) {
            Toast.makeText(this, "Please enter all the details!", Toast.LENGTH_SHORT).show();
        } else {
            if (password.equals(confirmpass))
                result = true;
            else
                Toast.makeText(this, "Confirm password doesn't match with your password!", Toast.LENGTH_SHORT).show();
        }
        return result;

    }
}

这是我的addcontacts java文件

package universe.sk.syndriveapp;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;

import android.support.v7.app.ActionBar;
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.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;


public class AddContacts extends AppCompatActivity {

    Button registerbtn;
     EditText etName,etEmailsign,etPassign,etBloodgroup,etDate;
    EditText name1, num1, name2, num2, name3, num3;
    String emname1,emname2,emname3;
    String emnum1,emnum2,emnum3;
    String name,email,password,bloodgrp,date;
    private FirebaseAuth firebaseAuth;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_addcontacts);

        ActionBar actionBar = getSupportActionBar();
        actionBar.setIcon(R.drawable.contacts);
        actionBar.setTitle(" Add Emergency Contacts");
        actionBar.setDisplayUseLogoEnabled(true);
        actionBar.setDisplayShowHomeEnabled(true);
        actionBar.setDisplayHomeAsUpEnabled(true);


        registerbtn= findViewById(R.id.registerbtn);

        name1 = findViewById(R.id.name1);
        num1 = findViewById(R.id.num1);

        name2 = findViewById(R.id.name2);
        num2 = findViewById(R.id.num2);
        name3 = findViewById(R.id.name3);
        num3 = findViewById(R.id.num3);
        setupUIViews();
        firebaseAuth = FirebaseAuth.getInstance();
        registerbtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                int value=checkData();
                if(value==1) {
                    emname1 = name1.getText().toString();
                    emnum1 = num1.getText().toString();
                    emname2 = name2.getText().toString();
                    emnum2 = num2.getText().toString();
                    emname3 = name3.getText().toString();
                    emnum3 = num3.getText().toString();
                    bloodgrp = etBloodgroup.getText().toString().trim();
                    date = etDate.getText().toString().trim();
                    name = etName.getText().toString();
                    password = etPassign.getText().toString();
                    email = etEmailsign.getText().toString();
                    adduser();
                    addcontacts();

                /*
                if (emname1.isEmpty() || emname2.isEmpty() || emname3.isEmpty()){
                    startActivity(new Intent(AddContacts.this, RegistrationActivity.class));
                    Toast.makeText(AddContacts.this, "", Toast.LENGTH_SHORT).show();
                }
                */

                    Toast.makeText(AddContacts.this, "Registration Success!", Toast.LENGTH_SHORT).show();
                    startActivity(new Intent(AddContacts.this, NavigationActivity.class));
                }
            }
        });
    }

    boolean isEmpty(EditText text){
        CharSequence str = text.getText().toString();
        return TextUtils.isEmpty(str);
    }

    int checkData(){
                if(isEmpty(name1) || isEmpty(name2) || isEmpty(name3) || isEmpty(num1) || isEmpty(num2) || isEmpty(num3)){
                    Toast.makeText(AddContacts.this,"Please fill all contact details",Toast.LENGTH_SHORT).show();
                    return -1;
                }
                else
                    return 1;
            }


    private void setupUIViews()
    {
        etName = findViewById(R.id.etName);
        etEmailsign = findViewById(R.id.etEmailsign);
        etPassign = findViewById(R.id.etPassign);

        etDate =(EditText)findViewById(R.id.etDate);
        etBloodgroup =(EditText) findViewById(R.id.etBloodgroup);
    }
    private void addcontacts(){
        FirebaseDatabase firebaseDatabase = FirebaseDatabase.getInstance();
        DatabaseReference databaseusers = firebaseDatabase.getReference(firebaseAuth.getUid());
        Contactdetails contactdetails;
        contactdetails = new Contactdetails(emname1,emname2,emname3,emnum1,emnum2,emnum3);
        databaseusers.setValue(contactdetails);
    }
    private void adduser(){
        FirebaseDatabase firebaseDatabase = FirebaseDatabase.getInstance();
        DatabaseReference databaseusers= firebaseDatabase.getReference(firebaseAuth.getUid());
        Userinfo user;
        user = new Userinfo(name,email,date,bloodgrp);
        databaseusers.setValue(user);

    }
}

这是我的userinfo java文件

package universe.sk.syndriveapp;

import android.net.Uri;

import com.google.android.gms.tasks.Task;

public class Userinfo {
    public String username;
    public String uemail;
    public String udate;
    public String bloodgroup;
    // public Uri imageUri;
    public Userinfo(){

    }

    public Userinfo(String username, String uemail, String udate, String bloodgroup) {
        this.username = username;
        this.uemail = uemail;
        this.udate = udate;
        this.bloodgroup = bloodgroup;
        // this.imageUri = imageUri;
    }

    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }

    public String getUemail() {
        return uemail;
    }
    public void setUemail(String uemail) {
        this.uemail = uemail;
    }

    public String getUdate(){
        return udate;
}
    public void setUdate(String udate) {
        this.udate = udate;
    }

    public String getBloodgroup() {
        return bloodgroup;
    }
    public void setBloodgroup(String bloodgroup) {
        this.bloodgroup = bloodgroup;
    }

    /* public Uri getImageUri() {
        return imageUri;
    }
    public void setImageUri(Uri imageUri) {
        this.imageUri = imageUri;
    } */
}

这是我的contactdetails Java文件

package universe.sk.syndriveapp;

public class Contactdetails {
    public String cname1;
    public  String cname2;
    public String cname3;
    public String no1;
    public String no2;
    public String no3;

    public Contactdetails(){

    }

    public Contactdetails(String cname1, String cname2, String cname3, String no1, String no2, String no3) {
        this.cname1 = cname1;
        this.cname2 = cname2;
        this.cname3 = cname3;
        this.no1 = no1;
        this.no2 = no2;
        this.no3 = no3;
    }

    public void setCname1(String cname1) {
        this.cname1 = cname1;
    }

    public void setCname2(String cname2) {
        this.cname2 = cname2;
    }

    public void setCname3(String cname3) {
        this.cname3 = cname3;
    }

    public void setNo1(String no1) {
        this.no1 = no1;
    }

    public void setNo2(String no2) {
        this.no2 = no2;
    }

    public void setNo3(String no3) {
        this.no3 = no3;
    }

    public String getCname1() {
        return cname1;
    }

    public String getCname2() {
        return cname2;
    }

    public String getCname3() {
        return cname3;
    }

    public String getNo1() {
        return no1;
    }

    public String getNo2() {
        return no2;
    }

    public String getNo3() {
        return no3;
    }
}

这是我的addcontacts xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"

    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="15dp"
    android:layout_marginLeft="15dp"
    android:layout_marginRight="15dp"
    android:layout_marginTop="15dp"
    android:orientation="vertical">

    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColorHint="@color/colorPrimary">
        <EditText
            android:id="@+id/name1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:ems="10"
            android:hint="@string/hint_emname1"
            android:inputType="textPersonName" />
    </android.support.design.widget.TextInputLayout>

    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColorHint="@color/colorPrimary">
        <EditText
            android:id="@+id/num1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:ems="10"
            android:hint="@string/hint_num1"
            android:inputType="phone" />
    </android.support.design.widget.TextInputLayout>

    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:textColorHint="@color/colorPrimary">

        <EditText
            android:id="@+id/name2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:ems="10"
            android:hint="@string/hint_emname2"
            android:inputType="textPersonName" />
    </android.support.design.widget.TextInputLayout>

    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColorHint="@color/colorPrimary">
        <EditText
            android:id="@+id/num2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:ems="10"
            android:hint="@string/hint_num2"
            android:inputType="phone" />
    </android.support.design.widget.TextInputLayout>

    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:textColorHint="@color/colorPrimary">

        <EditText
            android:id="@+id/name3"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"

            android:ems="10"
            android:hint="@string/hint_emname3"
            android:inputType="textPersonName" />
    </android.support.design.widget.TextInputLayout>

    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColorHint="@color/colorPrimary">
        <EditText
            android:id="@+id/num3"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:ems="10"
            android:hint="@string/hint_num3"
            android:inputType="phone" />
    </android.support.design.widget.TextInputLayout>

    <Button
        android:id="@+id/registerbtn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="24dp"
        android:layout_marginTop="25dp"
        android:background="@color/colorPrimary"
        android:text="@string/hint_registerbtn"
        android:textColor="#FFFFFF" />
</LinearLayout>

这是我的个人资料xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
    tools:context=".RegistrationActivity">


    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColorHint="@color/colorPrimary">
        <EditText
            android:id="@+id/etName"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginStart="8dp"
            android:layout_marginTop="8dp"
            android:ems="10"
            android:hint="@string/user_name"
            android:inputType="textPersonName"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.503"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.106" />
    </android.support.design.widget.TextInputLayout>

    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColorHint="@color/colorPrimary">
        <EditText
            android:id="@+id/etDate"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginStart="8dp"
            android:layout_marginTop="10dp"
            android:ems="10"
            android:hint="@string/date_of_birth"
            android:inputType="date" />
    </android.support.design.widget.TextInputLayout>

    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColorHint="@color/colorPrimary">
        <EditText
            android:id="@+id/etBloodgroup"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginStart="8dp"
            android:layout_marginTop="10dp"
            android:ems="10"
            android:hint="@string/blood_group"
            android:inputType="text" />
    </android.support.design.widget.TextInputLayout>

    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColorHint="@color/colorPrimary">
        <EditText
            android:id="@+id/etEmailsign"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginEnd="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginStart="8dp"
            android:layout_marginTop="10dp"
            android:ems="10"
            android:hint="@string/email"
            android:inputType="textEmailAddress"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.503"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/etDate" />
    </android.support.design.widget.TextInputLayout>

    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColorHint="@color/colorPrimary">
        <EditText
            android:id="@+id/etPassign"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginStart="8dp"
            android:layout_marginTop="10dp"
            android:ems="10"
            android:hint="@string/password"
            android:inputType="textPassword"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.503"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/etEmailsign"
            app:layout_constraintVertical_bias="0.08" />
    </android.support.design.widget.TextInputLayout>

    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColorHint="@color/colorPrimary">
        <EditText
            android:id="@+id/etConfirmPassign"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginStart="8dp"
            android:layout_marginTop="10dp"
            android:ems="10"
            android:hint="@string/confirm_password"
            android:inputType="textPassword"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.503"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/etPassign"
            app:layout_constraintVertical_bias="0.08" />
    </android.support.design.widget.TextInputLayout>

    <Button
        android:id="@+id/btn_register"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:background="@color/colorPrimary"
        android:text="@string/next"
        android:textColor="#FFFFFF"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/etConfirmPassign"
        app:layout_constraintVertical_bias="0.132" />

    <TextView
        android:id="@+id/tvExist"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:gravity="center_horizontal"
        android:text="Already an existing member? Login"
        android:textSize="18sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/btn_register" />
</LinearLayout>

最后这是我的错误日志

java.lang.NullPointerException: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference
    at universe.sk.syndriveapp.AddContacts$1.onClick(AddContacts.java:67)
    at android.view.View.performClick(View.java:5619)
    at android.view.View$PerformClick.run(View.java:22295)
    at android.os.Handler.handleCallback(Handler.java:754)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:163)
    at android.app.ActivityThread.main(ActivityThread.java:6237)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:877)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

Answer 1

您的addcontacts.xml没有ID为 etBloodgroup

的EditText

Answer 2

行

bloodgrp = etBloodgroup.getText().toString().trim();

导致错误。

您以前没有在findViewById() bloodgroup 上完成过EditText，而且在addcontacts.xml文件中也不存在。如果您在另一个xml文件中定义了它，则将无法在未与xml源关联的Activity中调用它（并且不能将多个xml布局文件与Activity关联））。

所以答案基本上是：在与您尝试处理的EditText相关的xml文件中定义Activity。

nullpointexception：将数据插入Firebase数据库时出错

2 个答案: