此代码无法转到下一页

Question

我想转到下一页（mainActivity）。 我能够注册并将该信息发送到数据库。 但只有成功消息和确定按钮出来。 错误不会出来。 请检查我的代码。

LoginActivity.java

package com.life.registeration;

import android.content.Intent;
import android.support.v7.app.AlertDialog;
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 com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.toolbox.Volley;

import org.json.JSONObject;

public class LoginActivity extends AppCompatActivity {

private AlertDialog dialog;

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

    TextView registerButton = (TextView) findViewById(R.id.registerButton);
    registerButton.setOnClickListener(new View.OnClickListener(){

        @Override
        public void onClick(View view) {
            Intent registerIntent = new Intent(LoginActivity.this, RegisterActivity.class);
            LoginActivity.this.startActivity(registerIntent);
        }
    });

    final EditText idText = (EditText) findViewById(R.id.idText);
    final EditText passwordText = (EditText) findViewById(R.id.passwordText);
    final Button loginButton = (Button) findViewById(R.id.loginButton);

    loginButton.setOnClickListener(new View.OnClickListener(){


        @Override
        public void onClick(View view) {
            String userID = idText.getText().toString();
            String userPassword = passwordText.getText().toString();

            Response.Listener<String> responseListener = new Response.Listener<String>(){

                @Override
                public void onResponse(String response) {
                    try {
                        JSONObject jsonResponse = new JSONObject(response);
                        boolean success = jsonResponse.getBoolean("success");
                        if(success){
                            AlertDialog.Builder builder = new AlertDialog.Builder(LoginActivity.this);
                            dialog = builder.setMessage("login success.")
                                    .setPositiveButton("ok", null)
                                    .create();
                            dialog.show();
                            Intent intent = new Intent(LoginActivity.this, MainActivity.class);
                            LoginActivity.this.startActivity(intent);
                            finish();
                        }
                        else{
                            AlertDialog.Builder builder = new AlertDialog.Builder(LoginActivity.this);
                            dialog = builder.setMessage("Please, check your id.")
                                    .setNegativeButton("retry", null)
                                    .create();
                            dialog.show();
                        }
                    }
                    catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            };
            LoginRequest loginRequest = new LoginRequest(userID, userPassword, responseListener);
            RequestQueue queue = Volley.newRequestQueue(LoginActivity.this);
            queue.add(loginRequest);
        }
    });
}

@Override
    protected void onStop(){
        super.onStop();
        if(dialog != null){
            dialog.dismiss();
            dialog = null;
        }
    }
}