android基础(Activity)

package ahu.edu;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class Activity03Activity extends Activity {
	

	
	private EditText factorOne;
	private EditText factorTwo;
	private TextView symbol;
	private Button calculate;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        factorOne = (EditText)findViewById(R.id.factorOne);
        factorTwo = (EditText)findViewById(R.id.factorTwo);
        symbol = (TextView)findViewById(R.id.symbol);
        calculate = (Button)findViewById(R.id.calculate);
        symbol.setText(R.string.symbol);
        calculate.setText(R.string.calculate);
        calculate.setOnClickListener(new CalcualteListener());
    }
    
    class CalcualteListener implements OnClickListener {
    	public void onClick(View v) {
    		String factorOneStr = factorOne.getText().toString();
    		String factorTwoStr = factorTwo.getText().toString();
    		Intent intent = new Intent();
    		intent.putExtra("one", factorOneStr);
    		intent.putExtra("two", factorTwoStr);
    		intent.setClass(Activity03Activity.this,ResualActivity.class);
    		Activity03Activity.this.startActivity(intent);
    	}
    }
    
	public boolean onCreateOptionsMenu(Menu menu) {
		menu.add(0, 1, 1,R.string.exit);
		menu.add(0, 2, 2,R.string.about);
		return super.onCreateOptionsMenu(menu);
	}
	
	public boolean onOptionsItemSelected(MenuItem item) {
		if(item.getItemId() == 1) {
			//finish();  //----比较柔和的方式
			System.exit(0); //---残酷的方式
		}
		return super.onOptionsItemSelected(item);
	}

}

package ahu.edu;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

public class ResualActivity extends Activity{
	private TextView resultView;
	
	
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.result);
		resultView = (TextView)findViewById(R.id.result);
		Intent intent = getIntent();
		String factorOneString = intent.getStringExtra("one");
		String factorTwoString = intent.getStringExtra("two");
		int factorOneInt = Integer.parseInt(factorOneString);
		int factorTwoInt = Integer.parseInt(factorTwoString);
		int result = factorOneInt * factorTwoInt;
		resultView.setText(result + "");
	}
}

<?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:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
    <EditText 
        android:id="@+id/factorOne"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:hint="@string/message" 
        android:inputType="none"/>
    <TextView 
        android:id="@+id/symbol"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text=""/>
    <EditText 
        android:id="@+id/factorTwo"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:hint="@string/message" 
        android:inputType="none"/>
    <Button 
       	android:id="@+id/calculate"
       	android:layout_width="fill_parent"
       	android:layout_height="wrap_content"
       	/>
    	
  
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="ahu.edu"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="10" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".Activity03Activity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity 
            android:name=".ResualActivity"
            android:label="@string/app_name">
            
        </activity>
    </application>

</manifest>