简单程序用于熟悉Activity生命周期

FirstActivity.java

public class FirstActivity extends Activity {
    /** Called when the activity is first created. */
    private Button myButton;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        System.out.println("FirstAcvity ---> onCreate");
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        myButton = (Button)findViewById(R.id.myButton);
        myButton.setText("启动第二个Activity");
        myButton.setOnClickListener(new ButtonOnClickListener());
    }

    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        System.out.println("FirstAcvity --->onDestory");
        super.onDestroy();
    }

    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        System.out.println("FirstAcvity --->onPause");
        super.onPause();
    }

    @Override
    protected void onRestart() {
        // TODO Auto-generated method stub
        System.out.println("FirstAcvity --->onRestart");
        super.onRestart();
    }

    @Override
    protected void onResume() {
        // TODO Auto-generated method stub
        System.out.println("FirstAcvity --->onResume");
        super.onResume();
    }

    @Override
    protected void onStart() {
        // TODO Auto-generated method stub
        System.out.println("FirstAcvity --->onStart");
        super.onStart();
    }

    @Override
    protected void onStop() {
        // TODO Auto-generated method stub
        System.out.println("FirstAcvity --->onStop");
        super.onStop();
    }
    
    class ButtonOnClickListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            Intent intent = new Intent();
            intent.setClass(FirstActivity.this,SecondActivity.class);
            FirstActivity.this.startActivity(intent);
        }
        
    }
    
}

SecondActivity.java

public class SecondActivity extends Activity {

	private Button secondButton;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		
		// TODO Auto-generated method stub
		System.out.println("SecondActivity--->onCreate");
		super.onCreate(savedInstanceState);
		setContentView(R.layout.second);
		secondButton = (Button)findViewById(R.id.secondButton);
		Gallery g = (Gallery)findViewById(R.id.secondButton);
		secondButton.setOnClickListener(new ButtonOnClickListener());
		
	}

	@Override
	protected void onDestroy() {
		// TODO Auto-generated method stub
		System.out.println("SecondActivity--->onDestory");
		super.onDestroy();
	}

	@Override
	protected void onPause() {
		// TODO Auto-generated method stub
		System.out.println("SecondActivity--->onPause");
		super.onPause();
	}

	@Override
	protected void onRestart() {
		// TODO Auto-generated method stub
		System.out.println("SecondActivity--->onRestart");
		super.onRestart();
	}

	@Override
	protected void onResume() {
		// TODO Auto-generated method stub
		System.out.println("SecondActivity--->onResume");
		super.onResume();
	}

	@Override
	protected void onStart() {
		// TODO Auto-generated method stub
		System.out.println("SecondActivity--->onStart");
		super.onStart();
	}

	@Override
	protected void onStop() {
		// TODO Auto-generated method stub
		System.out.println("SecondActivity--->onStop");
		super.onStop();
	}
	class ButtonOnClickListener implements OnClickListener{

		@Override
		public void onClick(View v) {
			Intent intent = new Intent();
			intent.setClass(SecondActivity.this,FirstActivity.class);
			SecondActivity.this.startActivity(intent);
		}
		
	}
}

 启动第一个Activity,然后启动第二个Activity,然后按返回键，然后再启动第二个Activity...查看输出结果。