android学习心得之Activity

ackage com.example.newcardgame;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity {
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		Button button1 = (Button)findViewById(R.id.button1);
		button1.setOnClickListener(new OnClickListener(){
			public void onClick(View v) {
				Toast.makeText(MainActivity.this, "You clicked Button1",
						Toast.LENGTH_SHORT).show();
			}		
		});
	}
	@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;
	}
}

<menu xmlns:android="http://schemas.android.com/apk/res/android" >
    <item
        android:id="@+id/action_settings"
        android:orderInCategory="100"
        android:showAsAction="never"
        android:title="@string/action_settings"/>
    <item
        android:id ="@+id/add_item"
        android:title="Add"/>
        
    <item
        android:id="@+id/remove_item"
        android:title="Remove"/>
</menu>

package com.example.newcardgame;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity {
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		Button button1 = (Button)findViewById(R.id.button1);
		button1.setOnClickListener(new OnClickListener(){
			public void onClick(View v) {
				Toast.makeText(MainActivity.this, "You clicked Button1",
						Toast.LENGTH_SHORT).show();
			}		
		});
	}
	public boolean onCreateOptionsMenu(Menu menu) {
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}
	public boolean onOptionsItemSelected(MenuItem item){
		switch(item.getItemId()){
		case R.id.add_item:
			Toast.makeText(MainActivity.this, "you clicked add",
					Toast.LENGTH_SHORT).show();
			break;
		case R.id.remove_item:
			Toast.makeText(MainActivity.this, "you clicked remove",
					Toast.LENGTH_SHORT).show();
			break;
		default:
		}
		return true;
	}
}

package com.example.newcardgame;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity {
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		Button button1 = (Button)findViewById(R.id.button1);
		button1.setOnClickListener(new OnClickListener(){
			public void onClick(View v) {
			Intent intent = new Intent(MainActivity.this,SecondActivity.class);
			startActivity(intent);	
			}		
		});
	}
}

<activity android:name=".SecondActivity">
<intent-fileter>
<action android:name="com.example.activityest.ACTION_START" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>

Intent intent = getIntent();
String data = inent.getStringExtra("extra_data");