Question

我是Android新手。我从互联网上复制了这段代码。此代码以前运行过。但现在应用程序崩溃了。 this shows up after clicking register不知道它崩溃的原因。我在Android Studio上使用Firebase处理登录注册类应用。它构建得很好，但是当我在手机上运行它时，启动器活动可以正常工作，但是当我使用我的按钮访问我的Firebase登录活动时会出现问题。我如何解决崩溃？

Java文件。

package com.example.omkar.smileservices;

import android.app.ProgressDialog;
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.util.Patterns;
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.auth.FirebaseUser;

public class signup extends AppCompatActivity implements View.OnClickListener{

private EditText inputName,inputEmail, inputPassword, inputConfirmPassword;
private Button btnRegister, btnSignIn;
private ProgressDialog progressDialog;
private FirebaseAuth mAuth;

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

    mAuth = FirebaseAuth.getInstance();

    if(mAuth.getCurrentUser() != null){
        //profile activity
        finish();
        startActivity(new Intent(signup.this,home.class));
    }

    progressDialog =new ProgressDialog(this);

    btnRegister = (Button) findViewById(R.id.register);
    btnSignIn = (Button) findViewById(R.id.signin);
    inputName = (EditText)findViewById(R.id.name);
    inputEmail = (EditText) findViewById(R.id.email);
    inputPassword = (EditText) findViewById(R.id.password);
    inputConfirmPassword = (EditText)findViewById(R.id.conpassw);

    btnRegister.setOnClickListener(this);
    btnSignIn.setOnClickListener(this);
}

@Override
public void onStart() {
    super.onStart();
    // Check if user is signed in (non-null) and update UI accordingly.
    FirebaseUser currentUser = mAuth.getCurrentUser();
}

@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.signin:
            startActivity(new Intent(signup.this,login.class));
            break;
        case R.id.register:
            register();
            break;
    }
}

public void register(){
    String name = inputName.getText().toString().trim();
    String email = inputEmail.getText().toString().trim();
    String password = inputPassword.getText().toString().trim();
    String confirmpassword = inputConfirmPassword.getText().toString().trim();

    if (TextUtils.isEmpty(name)) {
        Toast.makeText(getApplicationContext(), "Enter email address!", Toast.LENGTH_SHORT).show();
        return;
    }

    if (TextUtils.isEmpty(email)) {
        Toast.makeText(getApplicationContext(), "Enter email address!", Toast.LENGTH_SHORT).show();
        return;
    }

    if (!Patterns.EMAIL_ADDRESS.matcher(email).matches()){
        Toast.makeText(getApplicationContext(), "Enter valid email address!", Toast.LENGTH_SHORT).show();
        return;
    }

    if (TextUtils.isEmpty(password)) {
        Toast.makeText(getApplicationContext(), "Enter password!", Toast.LENGTH_SHORT).show();
        return;
    }

    if (TextUtils.isEmpty(confirmpassword)) {
        Toast.makeText(getApplicationContext(), "Enter password!", Toast.LENGTH_SHORT).show();
        return;
    }

    if (password.length() < 6) {
        Toast.makeText(getApplicationContext(), "Password too short, enter minimum 6 characters!", Toast.LENGTH_SHORT).show();
        return;
    }

    if(!confirmpassword.matches(password)){
        inputConfirmPassword.setError("Doesn't match the Password.");
        inputConfirmPassword.requestFocus();
        return;
    }

    progressDialog.setMessage("Registering..");
    progressDialog.show();

    //create user
    mAuth.createUserWithEmailAndPassword(email, password)
            .addOnCompleteListener(signup.this, new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {
                    Toast.makeText(signup.this, "createUserWithEmail:onComplete:" + task.isSuccessful(), Toast.LENGTH_SHORT).show();

                    if (!task.isSuccessful()) {
                       // progressDialog.dismiss();
                        Toast.makeText(signup.this, "Unable to Register. Please try Later", Toast.LENGTH_LONG).show();
                    } else {
                       // progressDialog.dismiss();
                        Toast.makeText(signup.this, "Registered Successfully..", Toast.LENGTH_SHORT).show();
                        Intent intent = new Intent(signup.this, home.class);
                        finish();
                        startActivity(intent);
                    }
                }
            });

}
}

崩溃日志

03-28 13:19:30.498 24522-24540/com.example.omkar.smileservices D/FA: Logging 
event (FE): screen_view(_vs), Bundle[{firebase_event_origin(_o)=auto, 
firebase_previous_class(_pc)=login, 
firebase_previous_id(_pi)=9003268579764646367, 
firebase_screen_class(_sc)=signup, 
firebase_screen_id(_si)=9003268579764646368}]
03-28 13:19:54.733 24522-24522/com.example.omkar.smileservices 
E/AndroidRuntime: FATAL EXCEPTION: main

Process: com.example.omkar.smileservices, PID: 24522

java.lang.NullPointerException: Attempt to invoke virtual method 
'android.text.Editable android.widget.EditText.getText()' on a null object reference
                                                                                 at com.example.omkar.smileservices.signup.register(signup.java:75)
                                                                                 at com.example.omkar.smileservices.signup.onClick(signup.java:68)
                                                                                 at android.view.View.performClick(View.java:5637)
                                                                                 at android.view.View$PerformClick.run(View.java:22429)
                                                                                 at android.os.Handler.handleCallback(Handler.java:751)
                                                                                 at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                 at android.os.Looper.loop(Looper.java:154)
                                                                                 at android.app.ActivityThread.main(ActivityThread.java:6119)
                                                                                 at java.lang.reflect.Method.invoke(Native Method)
                                                                                 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
                                                                                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

Answer 1

崩溃是由NullPointerException引起的，很可能是由以下行引起的：

inputName.getText().toString().trim();

正如日志中的错误所示：

尝试在null上调用虚方法EditText.getText() 对象参考

很明显，空对象引用是inputName，它应该指向XML布局中的editText。因此，在以下一行

 inputName = (EditText) findViewById(R.id.name);

findViewById方法未成功将视图绑定到名为inputName的EditText（view）变量。

正如评论中所建议的那样，您可以通过检查已设置的XML布局文件（即activity_signup.xml）是否包含ID为name的EditText来解决此问题。

即使代码正确，Android Firebase登录和注册应用也会崩溃。什么是解决方案

1 个答案: