Question

ArrayList<String> checkedValue2;

我有一个arrayList，其中我添加了检查的值，工作正常。检查/未检查工作正常，但问题是当应用程序重新启动时，arrayList为empty.how以保存arraylist对象.again当app重新启动时我检查取消选中它值添加删除。这是我的代码。

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        checkedValue = new ArrayList<String>();

当我点击复选框时，其值加载到arraylist，当我取消选中该值时删除app重启时arraylist为空plz告诉我如何保存arraylist aftar app restart.help我的一些代码

@Override
    public void onItemClick(AdapterView<?> arg0, View v, int position, long arg3) {
        // TODO Auto-generated method stub
        cb = (CheckBox) v.findViewById(R.id.checkBox1);
        TextView tv = (TextView) v.findViewById(R.id.textView);
        pi = (ApplicationInfo) arg0.getItemAtPosition(position);
        cb.performClick();

        if (cb.isChecked()) {

            checkedValue.add(tv.getText().toString());
            itemCheckedd[position] = true;
           // Toast.makeText(MainActivity.this, "all" + position, Toast.LENGTH_LONG).show();
        } else if (!cb.isChecked()) {
            checkedValue.remove(tv.getText().toString());

        }

      }

Answer 1

嗨，请阅读此链接 1＆gt;将数据存储在saveInstanceState

中

    static final String STATE_SCORE = "playerScore";
static final String STATE_LEVEL = "playerLevel";

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
// Save the user's current game state
savedInstanceState.putInt(STATE_SCORE, mCurrentScore);
savedInstanceState.putInt(STATE_LEVEL, mCurrentLevel);

// Always call the superclass so it can save the view hierarchy state
super.onSaveInstanceState(savedInstanceState);
}

2';检索数据

@Override

protected void onCreate（Bundle savedInstanceState）{ super.onCreate（savedInstanceState）; //始终先调用超类

// Check whether we're recreating a previously destroyed instance
if (savedInstanceState != null) {
    // Restore value of members from saved state
    mCurrentScore = savedInstanceState.getInt(STATE_SCORE);
    mCurrentLevel = savedInstanceState.getInt(STATE_LEVEL);
} else {
    // Probably initialize members with default values for a new instance
}
...

}

https://developer.android.com/training/basics/activity-lifecycle/recreating.html

您将把数据存储在savedInstanceState中，并在活动重启后从savedInstanceState

中获取数据

android如何保存arraylist对象并在app重启后获取它

1 个答案: