Android程序优化之异常终止数据恢复

• 当Activity异常终止时，系统会默认为我们保存部分数据 ，如果想自定义保存的数据以供恢复，可以重写onSaveInstanceState()来保存数据以及onRestoreInstanceState()来恢复数据。
• onSaveInstanceState()是使用Bundle来保存数据，可写 如下测试代码：

   @Override
    protected void onSaveInstanceState(Bundle outState) {
        outState.putString("mySave","保存的数据");
        Log.d("=======","onSaveInstanceState");
        super.onSaveInstanceState(outState);
    }

• onRestoreInstanceState()和onCreate()都可以用来恢复数据，在onCreate里需要判断Bundle里面是否有值，而onRestoreInstanceState()的Bundle里面一定是有值的。而且经过测试，onCreate()比onRestoreInstanceState()先执行。

 @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        String save=savedInstanceState.getString("mySave");
        Log.d("=======","onRestoreInstanceState"+save);
        super.onRestoreInstanceState(savedInstanceState);
    }

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_edit_text);
        if(savedInstanceState!=null){
            String save=savedInstanceState.getString("mySave");
            Log.d("=======","onCreate:"+save);
        }      
    }

运行结果如下：

=======: onSaveInstanceState =======: onCreate:保存的数据 =======: onRestoreInstanceState保存的数据