Activity Switching / 안드로이드 액티비티 전환 / 화면 전환

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:id="@+id/text"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="mainnnnnnnnnn"
    android:textSize="30sp"
    android:textColor="#ff0000"
    />
<Button
    android:id="@+id/call"  
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:onClick="mOnClick"
    android:text="Call"
    />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="ssssssssssub"
    android:textSize="20sp"
    android:textColor="#00ff00"
    />
<Button
    android:id="@+id/close"  
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:onClick="mOnClick"
    android:text="Close"
    />
</LinearLayout>

2. 동시에 subAcitivty.xml을 실제 화면상에 출력해주기위한 java 파일을 만듦니다.

  * xml 파일자체는 속성의 정보들을 저장할 뿐 아무런 역할을 하지 않습니다 이를 가져다 사용해주는 것이 필요하겠죠?

package com.example.activityswitching;
 
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
 
public class MainActivity extends Activity {
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
    }
 
    public void mOnClick(View v){
        Intent intent = new Intent(this,subActivity.class);
        startActivity(intent);
    }
    
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
 
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

package com.example.activityswitching;
 
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
 
public class subActivity extends Activity {
 
    
    @Override
    public void onCreate(Bundle bundle){
        super.onCreate(bundle);
        setContentView(R.layout.subactivity);
        
        
    }
    
    //버튼의 이벤트 핸들러
    public void mOnClick(View v){
        finish();
    }
}

3. AndroidManifest.xml에 등록

액티비티는 보안상이유때문에 반드시 메니페스트에 등록해야 합니다
메니페시트에 등록되지 않는 엑티비티는 사용하지 못합니다

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.activityswitching"
    android:versionCode="1"
    android:versionName="1.0" >
 
    <uses-sdk
        android:minSdkVersion="19"
        android:targetSdkVersion="19" />
 
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
 
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>


        <!-- 이렇게 액티비티를 등록합니다!!! -->
        <activity
            android:name="com.example.activityswitching.subActivity"
            android:label="subActivity"/> 


    </application>
 
</manifest>