안드로이드 스튜디오 < 로그인화면 만들기 >

activity_main.xml (첫화면,로그인 전 화면)

 
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:gravity="center"

    android:orientation="vertical"
    >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/textViewID"
            android:layout_width="100dp"
            android:layout_height="50dp"
            android:layout_weight="1"
            android:text="ID"
            android:textSize="28dp" />

        <EditText
            android:id="@+id/eid"
            android:layout_width="213dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:hint="ID" />

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/textViewpw"
            android:layout_width="100dp"
            android:layout_height="50dp"
            android:layout_weight="1"
            android:text="PW"
            android:textSize="26dp" />

        <EditText
            android:id="@+id/epw"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:ems="10"
            android:hint="password"
            android:inputType="textPassword" />

    </LinearLayout>

    <Button
        android:id="@+id/gotomenu"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="0"
        android:onClick="login"
        android:text="로그인" />

</LinearLayout>

activtiy_main2.xml (로그인 후 화면)
 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:gravity="center"
    android:orientation="vertical">


    <Button
        android:id="@+id/customerM"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="고객관리"
        />

    <Button
        android:id="@+id/profitM"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="매출관리"
        />
    <Button
        android:id="@+id/goodsM"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="상품관리"
        />

</LinearLayout>

MainActivity.java

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

    public class MainActivity extends AppCompatActivity {
        public static final int REQUEST_CODE_MENU=101;
        String userid="identity";
        String userpw="password";
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
        }
        @Override
        protected void onActivityResult(int requestCode, int resultCode, Intent data) {
            super.onActivityResult(requestCode, resultCode, data);
            if (requestCode == REQUEST_CODE_MENU) {
                if (resultCode == RESULT_OK) {
                    String menu = data.getExtras().getString("menu");
                    Toast.makeText(getApplicationContext(), "응답으로 전달된 menu :" + menu, Toast.LENGTH_LONG).show();
                }
            }
        }
        public void login(View v){
            EditText id=(EditText)findViewById(R.id.eid);
            EditText pw=(EditText)findViewById(R.id.epw);

            if(id.getText().toString().equals(userid)){
                if (pw.getText().toString().equals(userpw)){
                    Intent intent=new Intent(getApplicationContext(),Main2Activity.class);
                    startActivityForResult(intent,REQUEST_CODE_MENU);
                }
                else Toast.makeText(MainActivity.this,"로그인 실패",Toast.LENGTH_LONG).show();
            }
            else Toast.makeText(MainActivity.this,"로그인 실패",Toast.LENGTH_LONG).show();
        }

}

Main2Activity.java

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class Main2Activity extends AppCompatActivity {

    @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main2);

            Button customerM=(Button)findViewById(R.id.customerM);
            Button profitM=(Button)findViewById(R.id.profitM);
            Button goodsM=(Button)findViewById(R.id.goodsM);

        customerM.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.putExtra("menu","customer");
                setResult(RESULT_OK,intent);

                finish();
            }
        });
        profitM.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.putExtra("menu","profit");
                setResult(RESULT_OK,intent);

                finish();
            }
        });
        goodsM.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.putExtra("menu","goods");
                setResult(RESULT_OK,intent);

                finish();
            }
        });
    }
}