从嵌套数组中提取值

Question

我有一个名为社团的数组：

List<Society> societies = new ArrayList<>();

其中包含以下数据：

[{"society_id":1,"name":"TestName1","email":"Test@email1","description":"TestDes‌​1"},
{"society_id":2,"name":"TestName2","email":"Test@email2","description":"TestD‌​es2"},
{"society_id":3,"name":"TestName3","email":"Test@email3","description":"Tes‌​tDes3"}}

我将使用它来填充 ListView，但在编写将每个值数组分配到 ListView 中的位置的循环时遇到问题。 我想找到一种方法从数组中提取值并使用循环将它们分配给每个列表项，有人可以帮我吗？

我的代码（应该足够了，但如果您需要查看更多请询问）：

public class SocietySearch extends AppCompatActivity {

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


        List<Society> societies = new ArrayList<>();
        ServerRequests serverRequest1 = new ServerRequests(SocietySearch.this);
        serverRequest1.GetSocietyDataAsyncTask(societies, new GetSocietyCallback() {
            @Override
            public void done(List<Society> societies) {
                ListView lv = (ListView) findViewById(R.id.ListView);
                List<ListViewItem> items = new ArrayList<>();

                items.add(new ListViewItem() {{
                    ThumbnailResource = R.drawable.test;
                    Title = societies.socName;
                    Subtitle = societies.socDes;
                }});

                CustomListViewAdapter adapter = new CustomListViewAdapter(SocietySearch.this, items);
                lv.setAdapter(adapter);
            }
        });
    }


    class ListViewItem {
        public int ThumbnailResource;
        public String Title;
        public String Subtitle;
    } 

适配器类：

public class CustomListViewAdapter extends ArrayAdapter {

    LayoutInflater inflater;
    List<SocietySearch.ListViewItem> items;

    public CustomListViewAdapter(Activity context, List<SocietySearch.ListViewItem> items) {
        super(context, R.layout.item_row);

        this.items = items;
        this.inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        //Auto-generated method stub

        ListViewItem item = items.get(position);

        View vi = convertView;

        if (convertView == null)
            vi = inflater.inflate(R.layout.item_row, null);

        ImageView test = (ImageView) vi.findViewById(R.id.imgThumbnail);
        TextView txtTitle = (TextView) vi.findViewById(R.id.txtTitle);
        TextView txtSubTitle = (TextView) vi.findViewById(R.id.txtSubTitle);

        test.setImageResource(item.ThumbnailResource);
        txtTitle.setText(item.Title);
        txtSubTitle.setText(item.Subtitle);


        return vi;
    }
}

Answer 1

所以我们得出结论，我们需要有 for 循环来遍历 SocietySearch 类中的所有 Society 类：

@Override
public void done(List<Society> societies) {
    ListView lv = (ListView) findViewById(R.id.ListView);
    List<ListViewItem> items = new ArrayList<>();
    for(Society s : societies) {
        items.add(new ListViewItem() {{
            ThumbnailResource = R.drawable.test;
            Title = s.socName;
            Subtitle = s.socDes;
        }});
    }
    CustomListViewAdapter adapter = new CustomListViewAdapter(
        SocietySearch.this, items);
    lv.setAdapter(adapter);
}`

我们还必须修复 ArrayAdapter 的实现：

public class CustomListViewAdapter extends ArrayAdapter {

    LayoutInflater inflater;
    List<SocietySearch.ListViewItem> items;

    public CustomListViewAdapter(Activity context, List<SocietySearch.ListViewItem> items) {
        super(context, R.layout.item_row, **items**); // the constructor 
        //needs the reference of the list, even though we use our variable to 
        //populate the rows. I guess it has to know how many elements it contains to
        //iterate then through getView method, which is called for each row

        this.items = items;
        this.inflater = (LayoutInflater) context.getSystemService(
            Context.LAYOUT_INFLATER_SERVICE);
    }

Answer 2

您在寻找定制解决方案吗？这样您就可以将每个 ListViewItem 状态绑定到相应的列，然后您必须像 here 一样创建自定义解决方案。您需要为每一行自定义布局并扩展 ArrayAdapter，您可以在其中为一行绑定每一列。

这是你想知道的吗？如果没有，请您说的更具体些。

Answer 3

您正在创建一个匿名类并尝试在它的对象初始化程序中分配值。对象初始化程序没有对societies 的引用，这就是您收到编译错误的原因。试试这个：

class ListViewItem {
    private final int ThumbnailResource;
    private final String Title;
    private final String Subtitle;

    public ListViewItem(int thumbnail, String title, String subtitle) {
        ThumbnailResource = thumbnail;
        Title = title;
        Subtitle = subtitle;
    }
} 

添加列表项时：

items.add(new ListViewItem(R.drawable.test, societies.socName, societies.socDes);