Android 로그 인 인터페이스 에 등 록 된 인 스 턴 스 코드 구현

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
 package="online.geekgalaxy.layoutlearn"> 
 <application 
 android:allowBackup="true" 
 android:icon="@mipmap/ic_launcher" 
 android:label="@string/app_name" 
 android:roundIcon="@mipmap/ic_launcher_round" 
 android:supportsRtl="true" 
 android:theme="@style/AppTheme"> 
 <activity android:name=".MainActivity"> 
  <intent-filter> 
  <action android:name="android.intent.action.MAIN" /> 
  <category android:name="android.intent.category.LAUNCHER" /> 
  </intent-filter> 
 </activity> 
 <activity android:name=".login"> 
  <intent-filter> 
  <action android:name="android.intent.action.MAIN" /> 
  </intent-filter> 
 </activity> 
 <activity android:name=".register"> 
  <intent-filter> 
  <action android:name="android.intent.action.MAIN" /> 
  </intent-filter> 
 </activity> 
 </application> 
</manifest> 

package online.geekgalaxy.layoutlearn; 
import android.content.DialogInterface; 
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; 
public class MainActivity extends AppCompatActivity { 
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
 super.onCreate(savedInstanceState); 
 setContentView(R.layout.activity_main); 
 //login button 
 final Button login = (Button) findViewById(R.id.button); 
 final String user = "admin"; 
 final String pass = "hello"; 
 
 login.setOnClickListener(new View.OnClickListener() { 
  public void onClick(View view) { 
  String username = ""; 
  EditText editText1 = (EditText)findViewById(R.id.editText); 
  username = editText1.getText().toString(); 
  String password = ""; 
  EditText editText2 = (EditText)findViewById(R.id.editText2); 
  password = editText2.getText().toString(); 
  if (username.equals(user) & password.equals(pass)) { 
   Intent intent = new Intent(MainActivity.this, login.class); 
   startActivity(intent); 
  } 
  else { 
   new AlertDialog.Builder(MainActivity.this).setTitle("Error!").setMessage("Wrong username or password.") 
    .setNegativeButton("OK",null) 
    .show(); 
  } 
  } 
 }); 
 //register button 
 final Button register = (Button) findViewById(R.id.button2); 
 register.setOnClickListener(new View.OnClickListener() { 
  public void onClick(View view) { 
  //          
  new AlertDialog.Builder(MainActivity.this).setTitle("Jump").setMessage("Ready to jump?") 
   .setPositiveButton("Yes", new DialogInterface.OnClickListener() { 
    public void onClick(DialogInterface dialog, int which) { 
    Intent intent = new Intent(MainActivity.this, register.class); 
    startActivity(intent); 
    }}) 
   .setNegativeButton("No",null) 
   .show(); 
  } 
 }); 
 } 
} 

package online.geekgalaxy.layoutlearn; 
import android.app.Activity; 
import android.os.Bundle; 
/** 
 * Created by jailman on 2017/9/18. 
 */ 
public class login extends Activity { 
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
 super.onCreate(savedInstanceState); 
 setContentView(R.layout.login); 
 } 
} 

package online.geekgalaxy.layoutlearn; 
import android.app.Activity; 
import android.os.Bundle; 
/** 
 * Created by jailman on 2017/9/18. 
 */ 
public class register extends Activity{ 
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
 super.onCreate(savedInstanceState); 
 setContentView(R.layout.register); 
 } 
} 

<?xml version="1.0" encoding="utf-8"?> 
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" 
 xmlns:app="http://schemas.android.com/apk/res-auto" 
 xmlns:tools="http://schemas.android.com/tools" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent" 
 android:layout_centerVertical="true" 
 tools:context="online.geekgalaxy.layoutlearn.MainActivity"> 
 <Button 
 android:id="@+id/button" 
 android:layout_width="wrap_content" 
 android:layout_height="wrap_content" 
 android:layout_marginRight="68dp" 
 android:text="@string/login" 
 app:layout_constraintRight_toLeftOf="@+id/button2" 
 tools:layout_constraintTop_creator="1" 
 android:layout_marginEnd="68dp" 
 android:layout_marginTop="26dp" 
 app:layout_constraintTop_toBottomOf="@+id/editText2" /> 
 <Button 
 android:id="@+id/button2" 
 android:layout_width="wrap_content" 
 android:layout_height="wrap_content" 
 android:text="@string/register" 
 tools:layout_constraintTop_creator="1" 
 tools:layout_constraintRight_creator="1" 
 android:layout_marginEnd="68dp" 
 app:layout_constraintRight_toRightOf="parent" 
 android:layout_marginTop="26dp" 
 app:layout_constraintTop_toBottomOf="@+id/editText2" /> 
 <EditText 
 android:id="@+id/editText" 
 android:layout_width="240dp" 
 android:layout_height="45dp" 
 android:layout_marginBottom="35dp" 
 android:layout_marginEnd="68dp" 
 android:layout_marginLeft="8dp" 
 android:layout_marginRight="8dp" 
 android:layout_marginStart="68dp" 
 android:ems="10" 
 android:hint="@string/username" 
 android:inputType="textPersonName" 
 app:layout_constraintBottom_toTopOf="@+id/editText2" 
 app:layout_constraintHorizontal_bias="0.516" 
 app:layout_constraintLeft_toLeftOf="@+id/editText2" 
 app:layout_constraintRight_toRightOf="@+id/editText2" 
 tools:layout_constraintLeft_creator="1" 
 tools:layout_constraintRight_creator="1" 
 tools:layout_editor_absoluteX="-15dp" 
 tools:layout_editor_absoluteY="152dp" /> 
 <EditText 
 android:id="@+id/editText2" 
 android:layout_width="240dp" 
 android:layout_height="45dp" 
 android:layout_marginEnd="69dp" 
 android:layout_marginLeft="0dp" 
 android:layout_marginRight="0dp" 
 android:layout_marginStart="69dp" 
 android:ems="10" 
 android:hint="@string/password" 
 android:inputType="textPassword" 
 app:layout_constraintBottom_toBottomOf="parent" 
 app:layout_constraintLeft_toLeftOf="@+id/button" 
 app:layout_constraintRight_toRightOf="@+id/button2" 
 app:layout_constraintTop_toTopOf="parent" 
 tools:layout_constraintBottom_creator="1" 
 tools:layout_constraintLeft_creator="1" 
 tools:layout_constraintRight_creator="1" 
 tools:layout_constraintTop_creator="1" /> 
 <TextView 
 android:id="@+id/textView2" 
 android:layout_width="250dp" 
 android:layout_height="65dp" 
 android:layout_marginBottom="50dp" 
 android:layout_marginLeft="8dp" 
 android:layout_marginRight="8dp" 
 android:autoText="false" 
 android:text="Welcome" 
 android:textAlignment="center" 
 android:textSize="50sp" 
 android:textStyle="bold" 
 app:layout_constraintBottom_toTopOf="@+id/editText" 
 app:layout_constraintHorizontal_bias="0.509" 
 app:layout_constraintLeft_toLeftOf="@+id/editText" 
 app:layout_constraintRight_toRightOf="@+id/editText" /> 
</android.support.constraint.ConstraintLayout> 

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent" 
 android:weightSum="1"> 
 <TextView 
 android:id="@+id/textView3" 
 android:layout_width="0dp" 
 android:layout_height="118dp" 
 android:layout_marginTop="200dp" 
 android:layout_weight="1" 
 android:text="@string/great_you_ve_login" 
 android:textAlignment="center" 
 android:textSize="24sp" 
 android:textStyle="bold" /> 
</LinearLayout> 

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent"> 
 <LinearLayout 
 android:layout_width="match_parent" 
 android:layout_height="match_parent" 
 android:gravity="center_vertical|center_horizontal" 
 android:orientation="vertical"> 
 <EditText 
  android:id="@+id/editText5" 
  android:layout_width="270dp" 
  android:layout_height="wrap_content" 
  android:ems="10" 
  android:hint="Username" 
  android:inputType="textPersonName" /> 
 <EditText 
  android:id="@+id/editText6" 
  android:layout_width="270dp" 
  android:layout_height="wrap_content" 
  android:ems="10" 
  android:hint="Email" 
  android:inputType="textPersonName" /> 
 <EditText 
  android:id="@+id/editText7" 
  android:layout_width="270dp" 
  android:layout_height="wrap_content" 
  android:ems="10" 
  android:hint="Password" 
  android:inputType="textPassword" /> 
 <EditText 
  android:id="@+id/editText8" 
  android:layout_width="270dp" 
  android:layout_height="wrap_content" 
  android:ems="10" 
  android:hint="Confirm password" 
  android:inputType="textPassword" /> 
 <Button 
  android:id="@+id/button3" 
  android:layout_width="270dp" 
  android:layout_height="wrap_content" 
  android:text="Submit" /> 
 </LinearLayout> 
</LinearLayout> 

<resources> 
 <string name="app_name">LayoutLearn</string> 
 <string name="login">Login</string> 
 <string name="register">Register</string> 
 <string name="username">Username</string> 
 <string name="password">Password</string> 
 <string name="great_you_ve_login">Great, you\'ve logged in!</string> 
</resources> 

apply plugin: 'com.android.application' 
android { 
 compileSdkVersion 25 
 buildToolsVersion "25.0.3" 
 defaultConfig { 
 applicationId "online.geekgalaxy.layoutlearn" 
 minSdkVersion 19 
 targetSdkVersion 25 
 versionCode 1 
 versionName "1.0" 
 testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner" 
 } 
 buildTypes { 
 release { 
  minifyEnabled false 
  proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' 
 } 
 } 
} 
dependencies { 
 compile fileTree(dir: 'libs', include: ['*.jar']) 
 androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', { 
 exclude group: 'com.android.support', module: 'support-annotations' 
 }) 
 compile 'com.android.support:appcompat-v7:25.3.1' 
 compile 'com.android.support.constraint:constraint-layout:1.0.2' 
 testCompile 'junit:junit:4.12' 
}