如何在android中插入和选择mysql？

Question

LoginActivity.java

package tn.pack.ordre.enregistrer;


import org.json.JSONException;
import org.json.JSONObject;

import tn.pack.ordre.HomeActivity;
import tn.pack.ordre.R;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class LoginActivity extends Activity {

       @Override
       public void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
            setContentView(R.layout.ecran_accueil);

       }

      public void btn_enrg(View v){
        startActivity(new Intent(getApplicationContext(),EnregistrerActivity.class));
       }


      public void btn_login(View v) {

            EditText u = (EditText) findViewById (R.id.editText_username);
            EditText p = (EditText) findViewById (R.id.editText_motdepasse);

            String username = u.getText().toString();
            String password = p.getText().toString();

            UserFunctions userFunction = new UserFunctions();
            JSONObject json = userFunction.loginUser(username, password);
            Intent home =new Intent(getApplicationContext(),HomeActivity.class) ;

            // check for login response
            try {
                if (json.getString("success") != null) {
                    // loginErrorMsg.setText("");
                    String res = json.getString("success");
                    if (Integer.parseInt(res) == 1) {
                        // user successfully logged in
                        // Store user details in SQLite Database
                         JSONObject json_user = json.getJSONObject("user");
                         System.out.println(" "+json_user.getString("userName")+"  "+json_user.getString("created_at"));
                         //Bundle pass = new Bundle();
                         //pass.putString("userName", json_user.getString("userName"));
                         //pass.putString("created_at", json_user.getString("created_at"));
                         //home.putExtra("INTENT_EXTRA_STRING", pass);
                         //Log.d("test","uid:"+json.getString("uid")); 
                         startActivity(home);
                         finish();
                    } else {
                        // Error in login
                        Toast.makeText(getApplicationContext(), "Erreur login",3000).show();
                    }
                }
            } catch (JSONException e) {
                System.out.println("Connecter: "+e.toString());
            } 

        }  


    }

JSONParser.java -parser类解析api响应JSON。

package tn.pack.ordre.enregistrer;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;

import android.util.Log;

public class JSONParser {

    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";

    // constructor
    public JSONParser() {

    }

    public JSONObject getJSONFromUrl(String url, List<NameValuePair> params) {

        // Making HTTP request
        try {
            // defaultHttpClient
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);
            httpPost.setEntity(new UrlEncodedFormEntity(params));

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            is.close();
            json = sb.toString();
            Log.e("JSON", json);
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // return JSON String
        return jObj;

    }
}

EnregistrerActivity.java

package tn.pack.ordre.enregistrer;

    import org.json.JSONException;
    import org.json.JSONObject;

    import tn.pack.ordre.enregistrer.UserFunctions;

    import tn.pack.ordre.R;
    import android.app.Activity;
    import android.content.Intent;
    import android.os.Bundle;
    import android.view.View;
    import android.widget.EditText;
    import android.widget.TextView;

    public class EnregistrerActivity extends Activity {


    private TextView error;


       /** Called when the activity is first created. */
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
             // Fixe la mise en page d’une activité
            setContentView(R.layout.inscription);

        }



      public void btn_valider() {     

          String  user=((EditText)findViewById(R.id.et_un)).getText().toString();
          String password=((EditText)findViewById(R.id.et_pw)).getText().toString();
          String  rpassword=((EditText)findViewById(R.id.et_rpw)).getText().toString();
          String  cin=((EditText) findViewById(R.id.et_cin)).getText().toString();
//        String region = ((Spinner) findViewById (R.id.spinner_rg)).getSelectedItem().toString();



            UserFunctions userFunction = new UserFunctions();
            JSONObject json = userFunction.registerUser(user,password,rpassword,cin);
            try {

                 error=(TextView)findViewById(R.id.textViewerrer);
                if (json.getString("success") != null) {

                    String res = json.getString("success");
                    if (Integer.parseInt(res) == 1) {

                        error.setText("enregistrement ok"); 


                    } else {
                        error.setText("erreur pendant l'enregistrement"); 

                    }
                }
            } catch (JSONException e) {
                e.printStackTrace();
                System.out.println("btnRegister:  "+e.toString());
            }


         }

      public void Annuler(View v) {

                        startActivity(new Intent(getApplicationContext(),LoginActivity.class));

                       }
    }

UserFunctions.java-所有函数都将与JSONParser进行交互。

package tn.pack.ordre.enregistrer;

import java.util.ArrayList;
import java.util.List;

import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONObject;

public class UserFunctions {

    private JSONParser jsonParser;

    private static String loginURL = "http://10.0.2.2/webservice/index.php";
    private static String registerURL = loginURL;

    private static String login_tag = "login";
    private static String register_tag = "register";

    // constructor
    public UserFunctions(){
        jsonParser = new JSONParser();
    }


    public JSONObject loginUser(String userName, String password){
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("tag", login_tag));
        params.add(new BasicNameValuePair("userName", userName));
        params.add(new BasicNameValuePair("password", password));
        JSONObject json = jsonParser.getJSONFromUrl(loginURL, params);
        // return json
        // Log.e("JSON", json.toString());
        return json;
    }


    public JSONObject registerUser(String userName, String password,String rpassword, String cin){
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("tag", register_tag));
        params.add(new BasicNameValuePair("userName", userName));
        params.add(new BasicNameValuePair("cin", cin));
        params.add(new BasicNameValuePair("password", password));
        params.add(new BasicNameValuePair("rpassword", rpassword));
//        params.add(new BasicNameValuePair("region", region));


        // getting JSON Object
        JSONObject json = jsonParser.getJSONFromUrl(registerURL, params);
        // return json
        return json;
    }


}

config.php - 此文件包含连接数据库的常量变量。

<?php

/**
 * Database config variables
 */
define("DB_HOST", "localhost");
define("DB_USER", "root");
define("DB_PASSWORD", "");
define("DB_DATABASE", "appactel");
?>

DB_Connect.php - 此文件用于连接或断开数据库。

<?php
class DB_Connect {

    // constructor
    function __construct() {

    }

    // destructor
    function __destruct() {
        // $this->close();
    }

    // Connecting to database
    public function connect() {
        require_once 'include/config.php';
        // connecting to mysql
        $con = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);
        // selecting database
        mysql_select_db(DB_DATABASE);

        // return database handler
        return $con;
    }

    // Closing database connection
    public function close() {
        mysql_close();
    }

}

?>

DB_Functions.php - 该文件包含将用户存储在数据库中，从数据库中获取用户的功能。

 <?php

class DB_Functions {

    private $db;

    //put your code here
    // constructor
    function __construct() {
        require_once 'DB_Connect.php';
        // connecting to database
        $this->db = new DB_Connect();
        $this->db->connect();
    }

    // destructor
    function __destruct() {

    }

    /**
     * Storing new user
     * returns user details
     */
    public function storeUser($userName,$cin , $password, $repassword) {
        $uuid = uniqid('', true);
        $hash = $this->hashSSHA($password);
        $encrypted_password = $hash["encrypted"]; // encrypted password
        $salt = $hash["salt"]; // salt
        $result = mysql_query("INSERT INTO user_appmobile(unique_id, user_name, cin, encrypted_password,encrypted_repassword, salt, created_at, updated_at) VALUES('$uuid','$userName', $cin,'$encrypted_password', $encrypted_repassword,'$salt', NOW())");
        // check for successful store
        if ($result) {
            // get user details 
            $uid = mysql_insert_id(); // last inserted id
            $result = mysql_query("SELECT * FROM user_appmobile WHERE uid = $uid");
            // return user details
            return mysql_fetch_array($result);
        } else {
            return false;
        }
    }

    /**
     * Get user by email and password
     */
    public function getUserByCinAndPassword($cin, $password) {
        $result = mysql_query("SELECT * FROM user_appmobile WHERE cin = '$cin'") or die(mysql_error());
        // check for result 
        $no_of_rows = mysql_num_rows($result);
        if ($no_of_rows > 0) {
            $result = mysql_fetch_array($result);
            $salt = $result['salt'];
            $encrypted_password = $result['encrypted_password'];
            $hash = $this->checkhashSSHA($salt, $password);
            // check for password equality
            if ($encrypted_password == $hash) {
                // user authentication details are correct
                return $result;
            }
        } else {
            // user not found
            return false;
        }
    }

     /**
     * Get user by userName and password
     */
    public function getUserByUserNameAndPassword($userName, $password) {
        $result = mysql_query("SELECT * FROM user_appmobile WHERE user_name = '$userName'") or die(mysql_error());
        // check for result 
        $no_of_rows = mysql_num_rows($result);
        if ($no_of_rows > 0) {
            $result = mysql_fetch_array($result);
            $salt = $result['salt'];
            $encrypted_password = $result['encrypted_password'];
            $hash = $this->checkhashSSHA($salt, $password);
            // check for password equality
            if ($encrypted_password == $hash) {
                // user authentication details are correct
                return $result;
            }
        } else {
            // user not found
            return false;
        }
    }

    /**
     * Check user is existed or not
     */
    public function isUserExisted($cin) {
        $result = mysql_query("SELECT cin from user_appmobile WHERE cin = '$cin'");
        $no_of_rows = mysql_num_rows($result);
        if ($no_of_rows > 0) {
            // user existed 
            return true;
        } else {
            // user not existed
            return false;
        }
    }

        /**
     * Check user is existed or not
     */
    public function isUserNameExisted($userName) {
        $result = mysql_query("SELECT username from user_appmobile WHERE username = '$userName'");
        $no_of_rows = mysql_num_rows($result);
        if ($no_of_rows > 0) {
            // user Name existed 
            return true;
        } else {
            // user Name not existed
            return false;
        }
    }
       public function isCinExisted($cin) {
        $result = mysql_query("SELECT username from user_appmobile WHERE cin = '$cin'");
        $no_of_rows = mysql_num_rows($result);
        if ($no_of_rows > 0) {
            // user Name existed 
            return true;
        } else {
            // user Name not existed
            return false;
        }
    }

    /**
     * Encrypting password
     * @param password
     * returns salt and encrypted password
     */
    public function hashSSHA($password) {

        $salt = sha1(rand());
        $salt = substr($salt, 0, 10);
        $encrypted = base64_encode(sha1($password . $salt, true) . $salt);
        $hash = array("salt" => $salt, "encrypted" => $encrypted);
        return $hash;
    }

    /**
     * Decrypting password
     * @param salt, password
     * returns hash string
     */
    public function checkhashSSHA($salt, $password) {

        $hash = base64_encode(sha1($password . $salt, true) . $salt);

        return $hash;
    }


}
?>

index.php - 此文件扮演接受请求和提供响应的角色。 GET和POST请求。

<?php

 /**
 * check for POST request 
 */
if (isset($_POST['tag']) && $_POST['tag'] != '') {
    // get tag
    $tag = $_POST['tag'];

    // include db handler
    require_once 'include/DB_Functions.php';
    $db = new DB_Functions();

    // response Array
    $response = array("tag" => $tag, "success" => 0, "error" => 0);

    // check for tag type
    if ($tag == 'login') {
        // Request type is check Login
        $userName = $_POST['userName'];
        $password = $_POST['password'];

        // check for user
        $user = $db->getUserByUserNameAndPassword($userName, $password);
        if ($user != false) {
            // user found
            // echo json with success = 1
            $response["success"] = 1;
            $response["uid"] = $user["unique_id"];
            $response["user"]["userName"] = $user["user_name"];
            $response["user"]["cin"] = $user["cin"];
            $response["user"]["created_at"] = $user["created_at"];
            $response["user"]["updated_at"] = $user["updated_at"];
            echo json_encode($response);
        } else {
            // user not found
            // echo json with error = 1
            $response["error"] = 1;
            $response["error_msg"] = "Incorrect username or password!";
            echo json_encode($response);
        }
    } else if ($tag == 'register') {
        // Request type is Register new user


        $userName = $_POST['userName'];
        $cin = $_POST['cin'];
        $password = $_POST['password'];
        $repassword = $_POST['repassword'];
        $region = $_POST['region'];

        // check if user is already existed       a separer (cas cin & cas username )          
        if ( ($db->isUserNameExisted($userName))&&($db->isCinExisted($cin)) ) {
            // user is already existed - error response
            $response["error"] = 2;
            $response["error_msg"] = "User already existed";
            echo json_encode($response);
        } else {
            // store user
            $user = $db->storeUser($userName, $cin, $password, $repassword);
            if ($user) {
                // user stored successfully
                $response["success"] = 1;
                $response["uid"] = $user["unique_id"];
                $response["user"]["userName"] = $user["user_name"];
                $response["user"]["cin"] = $user["cin"];
                $response["user"]["created_at"] = $user["created_at"];
                $response["user"]["updated_at"] = $user["updated_at"];
                echo json_encode($response);
            } else {
                // user failed to store
                $response["error"] = 1;
                $response["error_msg"] = "Error occured in Registartion";
                echo json_encode($response);
            }
        }
    } else {
        echo "Invalid Request";
    }
} else {

        echo "Access Denied";
    }
    ?>

数据库：

    -- Base de données: `appactel`
    --
    -- Structure de la table `user_appmobile`
    --

    CREATE TABLE IF NOT EXISTS `user_appmobile` (
      `uid` int(11) NOT NULL AUTO_INCREMENT,
      `unique_id` varchar(23) NOT NULL,
      `user_name` varchar(20) NOT NULL,
      `cin` int(10) NOT NULL,
      `password` varchar(20) NOT NULL,
      `repassword` varchar(20) NOT NULL,
      `salt` varchar(10) NOT NULL,
      `created_at` datetime DEFAULT NULL,
      `updated_at` datetime DEFAULT NULL,
      PRIMARY KEY (`uid`)
    ) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

问题：

05-21 14:34:01.185: D/ddm-heap(223): Got feature list request
05-21 14:34:01.405: D/dalvikvm(223): GC freed 515 objects / 46800 bytes in 91ms
05-21 14:34:35.785: D/AndroidRuntime(223): Shutting down VM
05-21 14:34:35.785: W/dalvikvm(223): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
05-21 14:34:35.785: E/AndroidRuntime(223): Uncaught handler: thread main exiting due to uncaught exception
05-21 14:34:35.835: E/AndroidRuntime(223): java.lang.IllegalStateException: Could not find a method btn_valider(View) in the activity
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.view.View$1.onClick(View.java:2020)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.view.View.performClick(View.java:2364)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.view.View.onTouchEvent(View.java:4179)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.widget.TextView.onTouchEvent(TextView.java:6541)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.view.View.dispatchTouchEvent(View.java:3709)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
05-21 14:34:35.835: E/AndroidRuntime(223):  at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1659)
05-21 14:34:35.835: E/AndroidRuntime(223):  at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.app.Activity.dispatchTouchEvent(Activity.java:2061)
05-21 14:34:35.835: E/AndroidRuntime(223):  at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1643)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1691)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.os.Handler.dispatchMessage(Handler.java:99)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.os.Looper.loop(Looper.java:123)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.app.ActivityThread.main(ActivityThread.java:4363)
05-21 14:34:35.835: E/AndroidRuntime(223):  at java.lang.reflect.Method.invokeNative(Native Method)
05-21 14:34:35.835: E/AndroidRuntime(223):  at java.lang.reflect.Method.invoke(Method.java:521)
05-21 14:34:35.835: E/AndroidRuntime(223):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
05-21 14:34:35.835: E/AndroidRuntime(223):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
05-21 14:34:35.835: E/AndroidRuntime(223):  at dalvik.system.NativeStart.main(Native Method)
05-21 14:34:35.835: E/AndroidRuntime(223): Caused by: java.lang.NoSuchMethodException: btn_valider
05-21 14:34:35.835: E/AndroidRuntime(223):  at java.lang.ClassCache.findMethodByName(ClassCache.java:308)
05-21 14:34:35.835: E/AndroidRuntime(223):  at java.lang.Class.getMethod(Class.java:1014)
05-21 14:34:35.835: E/AndroidRuntime(223):  at android.view.View$1.onClick(View.java:2017)
05-21 14:34:35.835: E/AndroidRuntime(223):  ... 23 more
05-21 14:34:35.875: I/dalvikvm(223): threadid=7: reacting to signal 3
05-21 14:34:35.895: I/dalvikvm(223): Wrote stack trace to '/data/anr/traces.txt'
05-21 14:34:39.275: I/Process(223): Sending signal. PID: 223 SIG: 9
05-21 14:34:39.924: D/dalvikvm(232): GC freed 542 objects / 47816 bytes in 84ms
05-21 14:35:15.314: W/ActivityThread(254): Application tn.pack.ordre is waiting for the debugger on port 8100...
05-21 14:35:15.326: I/System.out(254): Sending WAIT chunk
05-21 14:35:15.878: I/dalvikvm(254): Debugger is active
05-21 14:35:16.005: I/System.out(254): Debugger has connected
05-21 14:35:16.005: I/System.out(254): waiting for debugger to settle...
05-21 14:35:16.215: I/System.out(254): waiting for debugger to settle...
05-21 14:35:16.443: I/System.out(254): waiting for debugger to settle...
05-21 14:35:16.645: I/System.out(254): waiting for debugger to settle...
05-21 14:35:16.866: I/System.out(254): waiting for debugger to settle...
05-21 14:35:17.126: I/System.out(254): waiting for debugger to settle...
05-21 14:35:17.348: I/System.out(254): waiting for debugger to settle...
05-21 14:35:17.585: I/System.out(254): waiting for debugger to settle...
05-21 14:35:17.829: I/System.out(254): waiting for debugger to settle...
05-21 14:35:18.077: I/System.out(254): waiting for debugger to settle...
05-21 14:35:18.300: I/System.out(254): waiting for debugger to settle...
05-21 14:35:18.511: I/System.out(254): waiting for debugger to settle...
05-21 14:35:18.721: I/System.out(254): waiting for debugger to settle...
05-21 14:35:18.930: I/System.out(254): waiting for debugger to settle...
05-21 14:35:19.159: I/System.out(254): waiting for debugger to settle...
05-21 14:35:19.366: I/System.out(254): waiting for debugger to settle...
05-21 14:35:19.576: I/System.out(254): waiting for debugger to settle...
05-21 14:35:19.795: I/System.out(254): debugger has settled (1483)

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="tn.pack.ordre"
    android:versionCode="1"
    android:versionName="1.0" xmlns:tools="http://schemas.android.com/tools" tools:ignore="UsesMinSdkAttributes">
    <uses-sdk android:minSdkVersion="7" />
    <uses-permission android:name="android.permission.INTERNET"></uses-permission>

    <application
        android:icon="@drawable/letter_m_blue"
        android:label="@string/app_name" >


        <activity android:name=".enregistrer.LoginActivity" >
             <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
        </activity>

        <activity android:name="tn.pack.ordre.enregistrer.EnregistrerActivity" />

        <activity

            android:name=".OrdredesTravauxActivity"
            android:label="@string/app_name" />


    </application>

</manifest>

ecran_accueil.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/launcher2"
    android:orientation="vertical" >


    <ImageView
        android:id="@+id/imageView_tt"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="30dp"
        android:background="@drawable/tt"
        android:contentDescription="@string/imagett" />







    <Button
        android:id="@+id/b_compte"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginTop="10dp"
        android:onClick="btn_enrg"
        android:text="@string/cr_er_un_compte" />

    <TextView
        android:id="@+id/textView_username"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:paddingTop="10dp"
        android:text="@string/user_name"
        android:textColor="#000000"
        android:textSize="20dp"
        android:textStyle="bold" />


    <EditText
        android:id="@+id/editText_username"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:inputType="textPersonName" >

        <requestFocus />

Answer 1

您确实意识到您在公共网站上发布了数据库root密码，对吗？ （编辑：没关系，它是一个本地服务器）

错误是：
Could not find a method btn_valider(View) in the activity

您应该更改方法：
public void btn_valider() {...}中的EnregistrerActivity 到
public void btn_valider(View someView) {...}