onCreate方法中saveInstanceState参数的作用

示例代码：

public class MainActivity extends ActionBarActivity {
	
	private static final String TAG = "MainActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (null != savedInstanceState) {
        	int intType = savedInstanceState.getInt("intType");
        	String stringType = savedInstanceState.getString("stringType");
        }
        setContentView(R.layout.activity_main);
        Log.i(TAG, "onCreate----履行了--------");        
    }
    
    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
    	super.onRestoreInstanceState(savedInstanceState);
    	int intType = savedInstanceState.getInt("intType");
    	String stringType = savedInstanceState.getString("stringType");
    	Log.i(TAG, "onRestoreInstanceState----履行了--------");
    }
    
    @Override
    protected void onSaveInstanceState(Bundle outState) {
    	super.onSaveInstanceState(outState);
    	outState.putInt("intType", 0);
    	outState.putString("stringType", "保留的");
    	Log.i(TAG, "onSaveInstanceState----履行了--------");
    }
}public class MainActivity extends ActionBar