我正在尝试创建一个使用 json 提要填充自身的动态列表。
我想为每个部分添加一个标题，以防联赛名称当前 json 提要通过一个联赛名称提供，但我需要使列表动态化以防添加另一个。
将来这是我正在寻找的那种布局。
联赛名称 项目 项目 项目 联赛名称 2 项目 项目 项目
我试图让它工作，但我得到了一个NullPointerException，我不知道为什么？
希望我已经足够简洁，任何帮助都会受到重视。
到目前为止，这是我的代码：
活动
try{
JSONObject obj = new JSONObject(FullData);
JSONObject objData = obj.getJSONObject("data");
JSONArray jArray = objData.getJSONArray("structure");
// JSONArray DivisionsArray = oneObject.getJSONArray("divisions");
// for (int d=0; d < DivisionsArray.length(); d++){
// JSONObject DivDict = DivisionsArray.getJSONObject(d);
// leagues.add(DivDict.getString("name"));
//}
//setListAdapter ( new ArrayAdapter<String>(this, R.layout.single_item, leagues));
//ListView list = getListView();
//list.setTextFilterEnabled(true);
// Create the ListView Adapter
adapter = new SeparatedListAdapter(this);
ArrayAdapter<String> listadapter = new ArrayAdapter<String>(this, R.layout.list_item, notes);
List<String> leagues = new ArrayList<String>();
// Add Sections
for (int i = 0; i < jArray.length(); i++)
{
JSONObject oneObject = jArray.getJSONObject(i);
leagues.add(oneObject.getString("league_website_name"));
Log.d("lc", "leagues: " + leagues);
adapter.addSection(leagues, listadapter);
}
// Get a reference to the ListView holder
journalListView = (ListView) this.findViewById(R.id.list_item_title);
// Set the adapter on the ListView holder
journalListView.setAdapter(adapter);
// Listen for Click events
journalListView.setOnItemClickListener(new OnItemClickListener()
{
public void onItemClick(AdapterView<?> parent, View view, int position, long duration)
{
String item = (String) adapter.getItem(position);
Toast.makeText(getApplicationContext(), item, Toast.LENGTH_SHORT).show();
}
});
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
分离式列表适配器
public class SeparatedListAdapter extends BaseAdapter
{
public final Map<String, Adapter> sections = new LinkedHashMap<String, Adapter>();
public final ArrayAdapter<String> headers;
public final static int TYPE_SECTION_HEADER = 0;
public SeparatedListAdapter(Context context)
{
headers = new ArrayAdapter<String>(context, R.layout.list_header);
}
public void addSection(String section, Adapter adapter)
{
this.headers.add(section);
this.sections.put(section, adapter);
}
public Object getItem(int position)
{
for (Object section : this.sections.keySet())
{
Adapter adapter = sections.get(section);
int size = adapter.getCount() + 1;
// check if position inside this section
if (position == 0) return section;
if (position < size) return adapter.getItem(position - 1);
// otherwise jump into next section
position -= size;
}
return null;
}
public int getCount()
{
// total together all sections, plus one for each section header
int total = 0;
for (Adapter adapter : this.sections.values())
total += adapter.getCount() + 1;
return total;
}
@Override
public int getViewTypeCount()
{
// assume that headers count as one, then total all sections
int total = 1;
for (Adapter adapter : this.sections.values())
total += adapter.getViewTypeCount();
return total;
}
@Override
public int getItemViewType(int position)
{
int type = 1;
for (Object section : this.sections.keySet())
{
Adapter adapter = sections.get(section);
int size = adapter.getCount() + 1;
// check if position inside this section
if (position == 0) return TYPE_SECTION_HEADER;
if (position < size) return type + adapter.getItemViewType(position - 1);
// otherwise jump into next section
position -= size;
type += adapter.getViewTypeCount();
}
return -1;
}
public boolean areAllItemsSelectable()
{
return false;
}
@Override
public boolean isEnabled(int position)
{
return (getItemViewType(position) != TYPE_SECTION_HEADER);
}
public View getView(int position, View convertView, ViewGroup parent)
{
int sectionnum = 0;
for (Object section : this.sections.keySet())
{
Adapter adapter = sections.get(section);
int size = adapter.getCount() + 1;
// check if position inside this section
if (position == 0) return headers.getView(sectionnum, convertView, parent);
if (position < size) return adapter.getView(position - 1, convertView, parent);
// otherwise jump into next section
position -= size;
sectionnum++;
}
return null;
}
public long getItemId(int position)
{
return position;
}
public void addSection(List<String> leagues,
ArrayAdapter<String> listadapter) {
// TODO Auto-generated method stub
}
}
list_complex.xml
<?xml version="1.0" encoding="utf-8"?>
<!-- list_complex.xml -->
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:paddingTop="10dip"
android:paddingBottom="10dip"
android:paddingLeft="15dip"
>
<TextView
android:id="@+id/list_complex_title"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
/>
<TextView
android:id="@+id/list_complex_caption"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
/>
</LinearLayout>
list_header.xml
<?xml version="1.0" encoding="utf-8"?>
<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/list_header_title"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingTop="2dip"
android:paddingBottom="2dip"
android:paddingLeft="5dip"
style="?android:attr/listSeparatorTextViewStyle" />
list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<!-- list_item.xml -->
<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/list_item_title"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:paddingTop="10dip"
android:paddingBottom="10dip"
android:paddingLeft="15dip"
android:textAppearance="?android:attr/textAppearanceLarge"
/>