Java 注册后，按back键进入登录屏幕

我制作了一个需要用户注册的应用程序。用户第一次打开应用程序-登录屏幕打开。他们需要点击“进入注册”按钮进入注册活动。注册后，他们将自动登录

现在问题来了——当用户第一次注册时，他被发送到MainActivity。他应该按back，应用程序应该关闭。但当他试图退出应用程序时，他按下后退按钮，而不是关闭应用程序，而是返回登录屏幕。 下次我尝试登录时，我没有问题-它直接进入主活动

我的活动是这样的：

后勤活动：

public class LoginActivity extends AppCompatActivity {
private static final String TAG = "LoginActivity";
private static final int REQUEST_REGISTER = 0;

@InjectView(R.id.input_email) EditText _emailText;
@InjectView(R.id.input_password) EditText _passwordText;
@InjectView(R.id.btn_login) Button _loginButton;
@InjectView(R.id.link_register) TextView _registerLink;

CheckBox checkBoxShowPassword;

private SessionManager session;
private SQLiteHandler db;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_login);
    ButterKnife.inject(this);

    // SQLite database handler
    db = new SQLiteHandler(getApplicationContext());
    // Session manager
    session = new SessionManager(getApplicationContext());
    // Check if user is already logged in or not
    if (session.isLoggedIn()) {
        // User is already logged in. Take him to main activity
        Intent intent = new Intent(LoginActivity.this, MainActivity.class);
        startActivity(intent);
        finish();
    }

    _loginButton.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            String email = _emailText.getText().toString().trim();
            String password = _passwordText.getText().toString().trim();

            if (!email.isEmpty() && !password.isEmpty()) {
                // login user
                login(email, password);
            } else {
                // Prompt user to enter credentials
                Toast.makeText(getApplicationContext(),
                        "Please enter the credentials!", Toast.LENGTH_LONG)
                        .show();
            }
        }
    });

    //        Go to register screen
    _registerLink.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // Start the Register activity
            Intent intent = new Intent(getApplicationContext(), RegisterActivity.class);
            startActivityForResult(intent, REQUEST_REGISTER);
        }
    });

    //        Password checkbox
    checkBoxShowPassword = (CheckBox) findViewById(R.id.checkBoxShowPassword);
    checkBoxShowPassword.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            // checkbox status is changed from uncheck to checked.
            if (!isChecked) {
                // show password
                _passwordText.setTransformationMethod(PasswordTransformationMethod.getInstance());
            } else {
                // hide password
                _passwordText.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
            }
        }
    });
}

//    Login
public void login(final String email, final String password) {
    Log.d(TAG, "Login");

    if (!validate()) {
        onLoginFailed();
        return;
    }

    //        Change to false for disabling after error
    _loginButton.setEnabled(true);

    String tag_string_req = "req_login";

    final ProgressDialog progressDialog = new ProgressDialog(LoginActivity.this,
            R.style.AppTheme_Dark_Dialog);
    progressDialog.setIndeterminate(true);
    progressDialog.setMessage("Authenticating...");
    progressDialog.show();

    // TODO: Implementing authentication logic

    StringRequest strReq = new StringRequest(Request.Method.POST,
            AppConfig.URL_LOGIN, new Response.Listener<String>() {

        @Override
        public void onResponse(String response) {
            Log.d(TAG, "Login Response: " + response.toString());
            progressDialog.dismiss();

            try {
                JSONObject jObj = new JSONObject(response);
                boolean error = jObj.getBoolean("error");

                // Check for error node in json
                if (!error) {
                    // user successfully logged in
                    // Create login session
                    session.setLogin(true);

                    // Now store the user in SQLite
                    String uid = jObj.getString("uid");

                    JSONObject user = jObj.getJSONObject("user");
                    String name = user.getString("name");
                    String email = user.getString("email");
                    String created_at = user
                            .getString("created_at");

                    // Inserting row in users table
                    db.addUser(name, email, uid, created_at);

                    // Launch main activity
                    Intent intent = new Intent(LoginActivity.this,
                            MainActivity.class);
                    startActivity(intent);
                    finish();
                } else {
                    // Error in login. Get the error message
                    String errorMsg = jObj.getString("error_msg");
                    Toast.makeText(getApplicationContext(),
                            errorMsg, Toast.LENGTH_LONG).show();
                }
            } catch (JSONException e) {
                // JSON error
                e.printStackTrace();
                Toast.makeText(getApplicationContext(), "Json error: " + e.getMessage(), Toast.LENGTH_LONG).show();
            }

        }
    }, new Response.ErrorListener() {

        @Override
        public void onErrorResponse(VolleyError error) {
            Log.e(TAG, "Login Error: " + error.getMessage());

            Toast toast = Toast.makeText(getApplicationContext(),
                    "Registration failed due to connectivity issues", Toast.LENGTH_LONG);
            toast.setGravity(Gravity.CENTER, 0, 0);
            toast.show();
    //                _loginButton.setEnabled(true);
            progressDialog.dismiss();

        }
    }) {

        @Override
        protected Map<String, String> getParams() {
            // Posting parameters to login url
            Map<String, String> params = new HashMap<String, String>();
            params.put("email", email);
            params.put("password", password);

            return params;
        }

    };

    // Adding request to request queue
    AppController.getInstance().addToRequestQueue(strReq, tag_string_req);


@Override
public void onBackPressed() {
    // disable going back to the MainActivity
    moveTaskToBack(true);
}

public void onLoginSuccess() {
    _loginButton.setEnabled(true);
    finish();
}

public void onLoginFailed() {
    Toast.makeText(getBaseContext(), "Login failed", Toast.LENGTH_LONG).show();

    _loginButton.setEnabled(true);
}

//    Validation
public boolean validate() {
    boolean valid = true;

    String email = _emailText.getText().toString();
    String password = _passwordText.getText().toString();

    if (email.isEmpty() || !android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
        _emailText.setError("Enter a valid email address");
        valid = false;
    } else {
        _emailText.setError(null);
    }

    if (password.isEmpty() || password.length() < 4 || password.length() > 20) {
        _passwordText.setError("Enter between 4 and 20 alphanumeric characters");
        valid = false;
    } else {
        _passwordText.setError(null);
    }

    return valid;
}
}

公共类LoginActivity扩展了AppCompatActivity{
私有静态最终字符串TAG=“LoginActivity”；
专用静态最终整数请求\寄存器=0；
@InjectView（R.id.input\u email）EditText\u emailText；
@InjectView（R.id.input_password）EditText_passwordText；
@InjectView（R.id.btn_登录）按钮_登录按钮；
@InjectView（R.id.link_register）TextView_registerLink；
复选框checkBoxShowPassword；
私人会话管理器会话；
私有SQLiteHandler数据库；
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity\u登录）；
注射（这个）；
//SQLite数据库处理程序
db=新的SQLiteHandler（getApplicationContext（））；
//会话管理器
session=newsessionmanager（getApplicationContext（））；
//检查用户是否已登录
if（session.isLoggedIn（））{
//用户已登录。请将其带到主活动
意向意向=新意向（LoginActivity.this、MainActivity.class）；
星触觉（意向）；
完成（）；
}
_loginButton.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
字符串email=_emailText.getText（）.toString（）.trim（）；
字符串密码=_passwordText.getText（）.toString（）.trim（）；
如果（！email.isEmpty（）&&！password.isEmpty（））{
//登录用户
登录（电子邮件、密码）；
}否则{
//提示用户输入凭据
Toast.makeText（getApplicationContext（），
“请输入凭据！”，Toast.LENGTH\u LONG）
.show（）；
}
}
});
//转到注册屏幕
_registerLink.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
//启动注册活动
Intent Intent=新的Intent（getApplicationContext（），RegisterActivity.class）；
startActivityForResult（意向、请求和登记）；
}
});
//密码复选框
checkBoxShowPassword=（复选框）findViewById（R.id.checkBoxShowPassword）；
checkBoxShowPassword.setOnCheckedChangeListener（新建CompoundButton.OnCheckedChangeListener（）{
检查更改后的公共无效（复合按钮视图，布尔值已检查）{
//复选框状态从未选中更改为已选中。
如果（！已检查）{
//显示密码
_setTransformationMethod（PasswordTransformationMethod.getInstance（））；
}否则{
//隐藏密码
_setTransformationMethod（HideReturnsTransformationMethod.getInstance（））；
}
}
});
}
//登录
公共无效登录（最终字符串电子邮件、最终字符串密码）{
Log.d（标记“登录”）；
如果（！validate（））{
onLoginFailed（）；
返回；
}
//更改为false以在出错后禁用
_loginButton.setEnabled（true）；
String tag\u String\u req=“req\u login”；
final ProgressDialog ProgressDialog=新建ProgressDialog（LoginActivity.this，
R.style.AppTheme（黑色对话框）；
progressDialog.setUndeterminate（true）；
progressDialog.setMessage（“身份验证…”）；
progressDialog.show（）；
//TODO:实现身份验证逻辑
StringRequest strReq=新的StringRequest（Request.Method.POST，
AppConfig.URL\u登录，新建响应.Listener（）{
@凌驾
公共void onResponse（字符串响应）{
Log.d（标记“登录响应：+Response.toString（））；
progressDialog.disclose（）；
试一试{
JSONObject jObj=新的JSONObject（响应）；
布尔错误=jObj.getBoolean（“错误”）；
//检查json中的错误节点
如果（！错误）{
//用户已成功登录
//创建登录会话
session.setLogin（true）；
//现在将用户存储在SQLite中
stringuid=jObj.getString（“uid”）；
JSONObject user=jObj.getJSONObject（“用户”）；
字符串名称=user.getString（“名称”）；
String email=user.getString（“电子邮件”）；
在=用户处创建的字符串
.getString（“创建于”）；
//在用户表中插入行
db.addUser（姓名、电子邮件、uid、创建地址）；
//开展主要活动
意向意向=新意向（LoginActivity.this，
主要活动（课堂）；
星触觉（意向）；
完成（）；
}否则{
//登录时出错。获取错误消息
String errorMsg=jObj.getString（“error_msg”）；
Toast.makeText（getApplicationContext（），
errorMsg，Toast.LENGTH_LONG）.show（）；
}
}捕获（JSONException e）{
//JSON错误
e、 printStackTrace（）；
Toast.makeText（getApplicationContext（），“Json错误：”+e.getMessa
public class RegisterActivity extends AppCompatActivity {
private static final String TAG = "RegisterActivity";

@InjectView(R.id.input_name) EditText _nameText;
@InjectView(R.id.input_email) EditText _emailText;
@InjectView(R.id.input_password) EditText _passwordText;
@InjectView(R.id.btn_register) Button _registerButton;
@InjectView(R.id.link_login) TextView _loginLink;

CheckBox checkBoxShowPassword;

private SessionManager session;
private SQLiteHandler db;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_register);
    ButterKnife.inject(this);

    // Session manager
    session = new SessionManager(getApplicationContext());
    // SQLite database handler
    db = new SQLiteHandler(getApplicationContext());
    // Check if user is already logged in or not
    if (session.isLoggedIn()) {
        // User is already logged in. Take him to main activity
        Intent intent = new Intent(RegisterActivity.this,
                MainActivity.class);
        startActivity(intent);
        finish();
    }

    //        Register button
    _registerButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String name = _nameText.getText().toString().trim();
            String email = _emailText.getText().toString().trim();
            String password = _passwordText.getText().toString().trim();
            String phone = getMyPhoneNumber();

            if (!name.isEmpty() && !email.isEmpty() && !password.isEmpty()) {
                register(name, email, password, phone);
            } else {
                Toast.makeText(getApplicationContext(),
                        "Please enter your details!", Toast.LENGTH_LONG)
                        .show();
            }
        }
    });

    //        Go to login screen
    _loginLink.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            // Finish the registration screen and return to the Login activity
            finish();
        }
    });

    //        Password checkbox
    checkBoxShowPassword = (CheckBox) findViewById(R.id.checkBoxShowPassword);
    checkBoxShowPassword.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            // checkbox status is changed from uncheck to checked.
            if (!isChecked) {
                // show password
                _passwordText.setTransformationMethod(PasswordTransformationMethod.getInstance());
            } else {
                // hide password
                _passwordText.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
            }
        }
    });
}

   //    Register
public void register(final String name, final String email, final String password, final String phone) {
    Log.d(TAG, "Register");

    if (!validate()) {
        onRegisterFailed();
        return;
    }

    _registerButton.setEnabled(false);

    String tag_string_req = "req_register";

    final ProgressDialog progressDialog = new ProgressDialog(RegisterActivity.this,
            R.style.AppTheme_Dark_Dialog);
    progressDialog.setIndeterminate(true);
    progressDialog.setMessage("Creating Account...");
    progressDialog.show();

    // TODO: Implementing register logic
    StringRequest strReq = new StringRequest(Request.Method.POST,
            AppConfig.URL_REGISTER, new Response.Listener<String>() {

        @Override
        public void onResponse(String response) {
            Log.d(TAG, "Register Response: " + response.toString());
            progressDialog.dismiss();

            try {
                JSONObject jObj = new JSONObject(response);
                boolean error = jObj.getBoolean("error");
                if (!error) {
                    // User successfully stored in MySQL
                    // Now store the user in sqlite
                    String uid = jObj.getString("uid");

                    JSONObject user = jObj.getJSONObject("user");
                    String name = user.getString("name");
                    String email = user.getString("email");
                    String created_at = user
                            .getString("created_at");

                    // Inserting row in users table
                    db.addUser(name, email, uid, created_at);

                    //TODO: insert contacts to local db
                    String[] PROJECTION = new String[] {
                            ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME,
                            ContactsContract.CommonDataKinds.Phone.NUMBER
                    };

                    Cursor phones = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, PROJECTION, null, null, null);
                    while (phones.moveToNext()) {
                        if (phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER) != -1)
                        {
                            String username = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
                            String phoneNumber = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));

                            db.addContact(username, phoneNumber);
                        }
                    }
                    phones.close();

                    Toast.makeText(getApplicationContext(), "Registration successful!", Toast.LENGTH_LONG).show();

     //                        Auto login
                    session.setLogin(true);

                    // Launch login activity
                    Intent intent = new Intent(
                            RegisterActivity.this,
                            MainActivity.class);
                    startActivity(intent);
                    finish();
                } else {

                    // Error occurred in registration. Get the error
                    // message
                    String errorMsg = jObj.getString("error_msg");
                    Toast.makeText(getApplicationContext(),
                            errorMsg, Toast.LENGTH_LONG).show();
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }

        }
    }, new Response.ErrorListener() {

        @Override
        public void onErrorResponse(VolleyError error) {
            Log.e(TAG, "Registration Error: " + error.getMessage());
            Toast toast = Toast.makeText(getApplicationContext(),
                    "Registration failed due to connectivity issues", Toast.LENGTH_LONG);
            toast.setGravity(Gravity.CENTER, 0, 0);
            toast.show();
            _registerButton.setEnabled(true);
            progressDialog.dismiss();
        }
    }) {

        @Override
        protected Map<String, String> getParams() {
            // Posting params to register url
            Map<String, String> params = new HashMap<String, String>();
            params.put("name", name);
            params.put("email", email);
            params.put("password", password);
            params.put("phone", phone);

            return params;
        }

    };

    // Adding request to request queue
    AppController.getInstance().addToRequestQueue(strReq, tag_string_req);

}

public void onRegisterSuccess() {
    _registerButton.setEnabled(true);
    setResult(RESULT_OK, null);
    finish();
}

public void onRegisterFailed() {
    Toast.makeText(getBaseContext(), "Registration failed", Toast.LENGTH_LONG).show();

    _registerButton.setEnabled(true);
}

    //    Validation
public boolean validate() {
    boolean valid = true;

    String name = _nameText.getText().toString();
    String email = _emailText.getText().toString();
    String password = _passwordText.getText().toString();

    if (name.isEmpty() || name.length() < 3) {
        _nameText.setError("Enter at least 3 characters");
        valid = false;
    } else {
        _nameText.setError(null);
    }

    if (email.isEmpty() || !android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
        _emailText.setError("Enter a valid email address");
        valid = false;
    } else {
        _emailText.setError(null);
    }

    if (password.isEmpty() || password.length() < 4 || password.length() > 20) {
        _passwordText.setError("Enter between 4 and 20 alphanumeric characters");
        valid = false;
    } else {
        _passwordText.setError(null);
    }

    return valid;
}

// Get users phone number
private String getMyPhoneNumber() {
    TelephonyManager tMgr = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
    String MyPhoneNumber = "0000000000";

    try
    {
        MyPhoneNumber =tMgr.getLine1Number();
    }
    catch(NullPointerException ex)
    {
    }

    if(MyPhoneNumber.equals("")){
        MyPhoneNumber = tMgr.getSubscriberId();
    }

    return MyPhoneNumber;
}

private String getMy10DigitPhoneNumber() {
    String s = getMyPhoneNumber();
    return s.substring(2);
}
}

Intent intent = new Intent(getApplicationContext(), RegisterActivity.class);
startActivityForResult(intent, REQUEST_REGISTER);

Intent intent = new Intent(getApplicationContext(), RegisterActivity.class);
startActivity(intent);
finish();

    //        Go to register screen
        _registerLink.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // Start the Register activity
                Intent intent = new Intent(getApplicationContext(), RegisterActivity.class);
                startActivityForResult(intent, REQUEST_REGISTER);
                LoginActivity.this.finish(); 
            }
        });

    public static LoginActivity mLogin_activity;
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mLogin_activity=LoginActivity.this;

  @Override
        public void onBackPressed() {
            super.onBackPressed();
            if (LoginActivity.mLogin_activity!=null) {
                LoginActivity.mLogin_activity.finish();
                MainActivity.this.finish();
            }else {
                MainActivity.this.finish();
            }
        }