我在下面编写这段代码，这是一个简单的用户注册选项，当我按下“创建我的帐户”按钮时，我得到: 任何人都可以弄清楚为什么？我自己也弄不明白。 提前谢谢大家
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 12-28 18:38:57.792 3358-3358/gr.aegean.icsd15109.myfitup E/AndroidRuntime: FATAL EXCEPTION: main Process: gr.aegean.icsd15109.myfitup, PID: 3358 java.lang.NullPointerException at gr.aegean.icsd15109.myfitup.RegisterActivity.registerUser(RegisterActivity.java:51) at gr.aegean.icsd15109.myfitup.RegisterActivity$1.onClick(RegisterActivity.java:45) at android.view.View.performClick(View.java:4438) at android.view.View$PerformClick.run(View.java:18422) at android.os.Handler.handleCallback(Handler.java:733) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:136) at android.app.ActivityThread.main(ActivityThread.java:5017) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:515) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) at dalvik.system.NativeStart.main(Native Method)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
代码:
import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.design.widget.TextInputEditText;
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 org.w3c.dom.Text;
public class RegisterActivity extends AppCompatActivity {
private EditText mDisName;
private EditText mMail;
private EditText mPass;
private Button reg;
private TextView error;
private FirebaseAuth mAuth;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
mDisName =(EditText) findViewById(R.id.reg_name);
mMail = (EditText) findViewById(R.id.reg_mail);
mPass = (EditText) findViewById(R.id.reg_password);
reg = (Button) findViewById(R.id.reg_button);
error = (TextView) findViewById(R.id.textView4);
reg.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String disName = mDisName.getText().toString();
String dmail = mMail.getText().toString();
String pass = mPass.getText().toString();
registerUser(disName,dmail,pass);
}
});
}
public void registerUser(String display_name,String email,String password){
mAuth.createUserWithEmailAndPassword(email,password).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
if(task.isSuccessful()){
Intent loginIntent = new Intent(RegisterActivity.this,login.class);
startActivity(loginIntent);
finish();
}
else{
Toast.makeText(RegisterActivity.this,"Error with registration!",Toast.LENGTH_LONG).show();
error.setText("Error 110! User already exists! \n Please provide different username!");
}
}
});
}
}
XML 代码:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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"
tools:context="gr.aegean.icsd15109.myfitup.account">
<android.support.design.widget.TextInputLayout
android:id="@+id/textInputLayout2"
android:layout_width="330dp"
android:layout_height="wrap_content"
android:layout_marginTop="48dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<android.support.design.widget.TextInputEditText
android:id="@+id/reg_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="@string/display_name" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:id="@+id/textInputLayout3"
android:layout_width="330dp"
android:layout_height="62dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="20dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textInputLayout2">
<android.support.design.widget.TextInputEditText
android:id="@+id/reg_mail"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="@string/email" />
</android.support.design.widget.TextInputLayout>
<Button
android:id="@+id/reg_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginRight="16dp"
android:layout_marginTop="56dp"
android:text="@string/create_account"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/reg_password"
tools:ignore="RtlHardcoded" />
<EditText
android:id="@+id/reg_password"
android:layout_width="330dp"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="12dp"
android:ems="10"
android:hint="@string/password2"
android:inputType="textPassword"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.526"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textInputLayout3" />
<TextView
android:id="@+id/textView4"
android:layout_width="262dp"
android:layout_height="55dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="44dp"
android:textColor="@android:color/holo_red_dark"
android:textStyle="bold"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/reg_button" />
</android.support.constraint.ConstraintLayout>
最佳答案
mAuth 在你的代码中是空的..你没有得到它的实例
这样做:
在 onCreate() 方法中，初始化 FirebaseAuth 实例:
mAuth = FirebaseAuth.getInstance();
那么你就可以使用这个方法了:
mAuth.createUserWithEmailAndPassword(email, password)
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
更多信息请查看:https://firebase.google.com/docs/auth/android/start/
关于java - android应用程序按钮onClick监听器错误，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/48015787/