Android 横竖屏切换时保存Activity状态

// 保存
@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
  super.onSaveInstanceState(savedInstanceState);
  // Save UI state changes to the savedInstanceState.
  // This bundle will be passed to onCreate if the process is
  // killed and restarted.
  savedInstanceState.putBoolean("MyBoolean", true);
  savedInstanceState.putDouble("myDouble", 1.9);
  savedInstanceState.putInt("MyInt", 1);
  savedInstanceState.putString("MyString", "Welcome back to Android");
  // etc.
}
           

// 恢复
@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
  super.onRestoreInstanceState(savedInstanceState);
  // Restore UI state from the savedInstanceState.
  // This bundle has also been passed to onCreate.
  boolean myBoolean = savedInstanceState.getBoolean("MyBoolean");
  double myDouble = savedInstanceState.getDouble("myDouble");
  int myInt = savedInstanceState.getInt("MyInt");
  String myString = savedInstanceState.getString("MyString");
}
           

CAREFUL: you need to call super.onSaveInstanceState(savedInstanceState) before adding your values to the Bundle, or they will get wiped out on that call (Droid X Android 2.2).先调用super.onSaveInstanceState(savedInstanceState)方法，然后再添加值

*** 重要的信息还是要在onPause()中就保存到SharedPreferece或SQlite中，因为onSaveInstanceState不是声明周期中的方法，不能保证每次都能调用

developer.android.com/reference/android/app/Activity.html 

http://stackoverflow.com/questions/151777/saving-activity-state-in-android