如何在Arraylist中使用onSaveInstanceState方法

Question

我已经构建了一个带有API结果的ArrayList.当用户转动手机时,我不希望它消失.

我该怎么办onSaveInstanceState？

JSONObject json = new JSONObject(result);

                    JSONArray searchArray = json.getJSONArray("Search");

                    for (int i = 0; i < searchArray.length(); i++) {
                        JSONObject searchObject = searchArray.getJSONObject(i);
                        String title = searchObject.getString("Title");
                        String type = searchObject.getString("Type");
                        String year = searchObject.getString("Year");
                        String imdbID = searchObject.getString("imdbID");

                        movieList.add(new Movie(title, type, year, imdbID));

Answer 1

假设您要跟踪的arrayList被调用myArrayList 此活动中的代码将满足您的目的:

对于String Array:

ArrayList myArrayList;

//put value of myArrayList in some other method

protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putStringArrayList("myArrayList", myArrayList);
}


protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);
    myArrayList = savedInstanceState.getStringArrayList("myArrayList");
}

对于自定义对象数组:

使对象的类实现接口Parcelable,然后将对象添加到ArrayList.在您的情况下,使Movie类实现Parcelable并添加对象movieList.

然后使用相同的方法而不是putStringArrayList()使用:

outState.putParcelableArrayList("movieList", movieList);

同样,使用:

movieList = (ArrayList<Movie>) savedInstanceState.getParcelableArrayList("movieList");

在onRestoreInstanceState()获取数组的方法中.