问savedInstanceState不为空，但没有数据
EN

Stack Overflow用户

提问于 2016-10-27 03:12:03

回答 2查看 231关注 0票数 0

我有一个片段活动，我导航到一个搜索页面，然后返回结果列表。有时需要重新创建活动，因此我将实例数据保存为：

@Override
public void onSaveInstanceState(Bundle outState) {

    super.onSaveInstanceState(outState);

    System.out.println("Saving instance state!");

    // Save the instance data
    // Filter data
    Intent mIntent = new Intent(this, BasicMapDemoActivity.class);
    filter.addFilterToIntent(mIntent);
    outState = mIntent.getExtras();

    // Save date data
    int year = currentDate.getYear();
    int month = currentDate.getMonth();
    int day = currentDate.getDay();
    outState.putInt("YEAR",year);
    outState.putInt("MONTH",month);
    outState.putInt("DAY",day);

    // Location data
    double latitude = mapLocation.latitude;
    double longitude = mapLocation.longitude;
    outState.putDouble("LATITUDE",latitude);
    outState.putDouble("LONGITUDE",longitude);

    // Other
    outState.putString("VIEW_MODE",viewMode.toString());
    outState.putString("SORT_TYPE",sortType);
    outState.putInt("ZOOM", mapZoom);
}

然后，我尝试恢复onCreate中的数据，但当我到达那里时，包不是空的，但它不包含我保存到其中的任何数据。下面所有的get函数都返回零(我在上面的代码块末尾确认数据是非零的)：

Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    // If we are 're-creating', then get the old instance data, otherwise set defaults
    if(savedInstanceState == null)
    {
        // Set up default instance data
        currentDate = new Date(115,4,1);
        filter = new ObajoFilter();
        filter.start = currentDate;
        filter.end = new Date(115,4,1,23,59,0);
        viewMode = ViewMode.MAP;
        sortType = "Distance";
        mapLocation = userLocation;
        mapZoom = 16;

    } else {

        // Get date data
        int year = savedInstanceState.getInt("YEAR");
        int month = savedInstanceState.getInt("MONTH");
        int day = savedInstanceState.getInt("DAY");
        currentDate = new Date(year,month,day);

有什么办法可以清空捆绑包吗？据我所知，只有当应用程序被完全销毁时，savedInstanceData才是空的。

java

android

android-activity

回答 2

Stack Overflow用户

发布于 2016-10-27 04:13:22

由于这一行，outState = mIntent.getExtras();

您的outState指向不同的地址mIntent.getExtras()，，因此它为空

您应该直接使用outState.putXX，而不是创建新对象。

票数 0

Stack Overflow用户

发布于 2016-10-27 04:14:15

您是否存储了要在onSaveInstanceState中保留的信息，如下所示

@Override
public void onSaveInstanceState(Bundle outState) {
    outState.putParcelable("someobject", someobject);
    outState.putBoolean("someboolean", someBoolean);
    outState.putInt("someint", someInt);
    super.onSaveInstanceState(outState);
}