php - 在通过 android app toast 访问 phpmyadmin 以获取电子邮件 ID 时不存在

Question

如果注册了新用户，我正在使用 PHPMyAdmin 构建一个用于登录注册的应用程序，那么登录部分也一切正常，但是在注册新用户时，如果存在相同的电子邮件 ID，则相同的 Toast 不会出现。

UserRegistration.php（注册文件）

  <?php
    if($_SERVER['REQUEST_METHOD']=='POST'){

    include 'DatabaseConfig.php';

     $con = mysqli_connect($HostName,$HostUser,$HostPass,$DatabaseName);

     $username = $_POST['username'];
     $email = $_POST['email'];
     $password = $_POST['password'];

     $CheckSQL = "SELECT * FROM users WHERE email='$email'";

     $check = mysqli_fetch_array(mysqli_query($con,$CheckSQL));

     if(isset($check))
     {
     echo 'Email Already Exist';
     }

    else
    { 
    $Sql_Query = "INSERT INTO users (username,email,password) values ('$username','$email','$password')";

     if(mysqli_query($con,$Sql_Query))
    {
     echo 'Registration Successful';
    }
    else
    {
     echo 'Something went wrong';
     }
     }
    }
     mysqli_close($con);
    ?>

MainActivity.java

package com.androidjson.userloginreg_androidjsoncom;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
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.ProgressBar;
import android.widget.Toast;
import java.util.HashMap;

import static java.lang.Boolean.FALSE;

public class MainActivity extends AppCompatActivity {

    Button register, log_in;
    EditText Username, Email, Password;
    String U_Name_Holder, EmailHolder, PasswordHolder;
    String finalResult ;
    String HttpURL = "http://qnorb.com/UserRegistration.php";
    Boolean CheckEditText ;
    ProgressDialog progressDialog;
    HashMap<String,String> hashMap = new HashMap<>();
    HttpParse httpParse = new HttpParse();


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

        //Assign Id'S
        Username = (EditText)findViewById(R.id.userName);
        Email = (EditText)findViewById(R.id.editTextEmail);
        Password = (EditText)findViewById(R.id.editTextPassword);

        register = (Button)findViewById(R.id.Submit);
        log_in = (Button)findViewById(R.id.Login);

        //Adding Click Listener on button.
        register.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                // Checking whether EditText is Empty or Not
                CheckEditTextIsEmptyOrNot();

                if(CheckEditText){
                    // If EditText is not empty and CheckEditText = True then this block will execute.
                    UserRegisterFunction(U_Name_Holder, EmailHolder, PasswordHolder);
                }

              /*  else if(android.util.Patterns.EMAIL_ADDRESS.matcher(Email.getText().toString()).matches()==FALSE)
                {
                    Toast.makeText(MainActivity.this, "Email ID invalid.", Toast.LENGTH_LONG).show();
                }*/

                else{
                    // If EditText is empty then this block will execute .
                    Toast.makeText(MainActivity.this, "Please fill all form fields.", Toast.LENGTH_LONG).show();

                }
            }
        });

        log_in.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view)
            {
                Intent intent = new Intent(MainActivity.this,UserLoginActivity.class);
                startActivity(intent);
            }
        });

    }

    public void CheckEditTextIsEmptyOrNot(){

        U_Name_Holder = Username.getText().toString();
        EmailHolder = Email.getText().toString();
        PasswordHolder = Password.getText().toString();


        if(TextUtils.isEmpty(U_Name_Holder) || TextUtils.isEmpty(EmailHolder) || TextUtils.isEmpty(PasswordHolder))
        {
            CheckEditText = false;
        }
        else {

            CheckEditText = true ;
        }

    }

    public void UserRegisterFunction(final String U_Name, final String email, final String password){

        class UserRegisterFunctionClass extends AsyncTask<String,Void,String> {
            private ProgressBar progressBar;

            @Override
            protected void onPreExecute() {
                super.onPreExecute();
                progressBar = (ProgressBar) findViewById(R.id.progressBar);
                progressBar.setVisibility(View.VISIBLE);
            }

            @Override
            protected void onPostExecute(String httpResponseMsg) {
                super.onPostExecute(httpResponseMsg);
                Toast.makeText(MainActivity.this, "Registration Successful", Toast.LENGTH_LONG).show();
                progressBar.setVisibility(View.GONE);
            }

            @Override
            protected String doInBackground(String... params) {

                hashMap.put("username",params[0]);
                hashMap.put("email",params[1]);
                hashMap.put("password",params[2]);

                finalResult = httpParse.postRequest(hashMap, HttpURL);

                return finalResult;
            }
        }

        UserRegisterFunctionClass userRegisterFunctionClass = new UserRegisterFunctionClass();

        userRegisterFunctionClass.execute(U_Name,email,password);
    }

}

标签： phpandroidmysql