小编Mit*_*are的帖子

我不能为我的生活弄清楚为什么我的ExpandableListView不会扩展...我已经在ExpandableListView中找到了几乎每个点击监听器的日志语句,它看起来并不像它们中的任何一个被调用.

我知道有很多关于这个主题的帖子,但是我已经阅读了所有内容并尝试了许多事情并且没有运气,希望我错过了一些很容易被其他人发现的小错误.

主要活动:

public class ForumListActivity extends Activity  {

    private static ArrayList<Forum> forumList;
    private static ArrayList<ArrayList<SubForum>> subForumList;
    private ExpandableListView forumListView;
    private ForumListAdapter forumListAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.setContentView(R.layout.main_page);
        this.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);

        forumListView = (ExpandableListView) this.findViewById(R.id.main_page_forum_list);

        forumList = new ArrayList<Forum>();
        subForumList = new ArrayList<ArrayList<SubForum>>();
        setUpForums(this);

        forumListAdapter = new ForumListAdapter(this, forumList, subForumList);
        forumListView.setAdapter(forumListAdapter);

        forumListView.setOnGroupExpandListener(new OnGroupExpandListener(){
            @Override
            public void onGroupExpand(int groupPosition) {
                Log.d("onGroupExpand", "this works?");
                for(int i=0; i<forumListAdapter.getGroupCount(); i++) {
                    if(i != groupPosition) 
                        forumListView.collapseGroup(groupPosition);
                }
            }
        });

        forumListView.setOnGroupClickListener(new OnGroupClickListener() {
            @Override
            public …

我正在尝试编写一个空安全的String适配器,它将这个JSON序列{"nullString": null}化为:Model(nullString = "")所以任何带有'null'值的JSON都会被替换为""(假设存在这样的数据类) :data class Model(val nullString: String))

我写了一个自定义适配器来尝试处理这个:

class NullStringAdapter: JsonAdapter<String>() {
    @FromJson
    override fun fromJson(reader: JsonReader?): String {
        if (reader == null) {
            return ""
        }

        return if (reader.peek() == NULL) "" else reader.nextString()
    }

    @ToJson
    override fun toJson(writer: JsonWriter?, value: String?) {
        writer?.value(value)
    }
}

...试图解决此解析错误:

com.squareup.moshi.JsonDataException: Expected a name but was NULL at path $.nullString

Moshi解析代码:

val json = "{\"nullString\": null}"

val moshi = Moshi.Builder()
    .add(KotlinJsonAdapterFactory())
    .add(NullStringAdapter()) …