Android实现手机返回键返回上一级Activity

实现了从FirstActivity页面返回到SecondActivity页面功能，这里面涉及到了onKeyDown（捕获返回键）和Intent跳转

public boolean onKeyDown(int keyCode, KeyEvent event) {

if (keyCode == KeyEvent.KEYCODE_BACK) {

//startActivity(new Intent(FirstActivity.this, SecondActivity.class));

Intent intent=new Intent(FirstActivity.this, SecondActivity.class));

                        startActivity(intent);

finish();//跳转页面的同事记得关闭当前页面.
}
return super.onKeyDown(keyCode, event);
}