对不起，这是java编程的新手。所以这里......我有一个可扩展的列表视图，它是通过JSON数组从我的MySQL数据库中填充的。数据库是他们要求的人员和礼物的列表。一切顺利。我现在想给孩子添加一个按钮，但前提是尚未购买礼物。
这是我的代码（删节）
expandable list adapter.Java
public class ExpandableListAdapter extends BaseExpandableListAdapter {
private Context _context;
private List<String> _listDataHeader; // header titles
// child data in format of header title, child title
private HashMap<String, List<String>> _listDataChild;
public ExpandableListAdapter(Context context, List<String> listDataHeader, HashMap<String, List<String>> listChildData) {
this._context = context;
this._listDataHeader = listDataHeader;
this._listDataChild = listChildData;
}
@Override
public Object getChild(int groupPosition, int childPosititon) {
return this._listDataChild.get(this._listDataHeader.get(groupPosition)).get(childPosititon);
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
@Override
public View getChildView(int groupPosition, final int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
final String childText = (String) getChild(groupPosition, childPosition);
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) this._context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.list_item, null);
}
TextView txtListChild = (TextView) convertView.findViewById(R.id.lblListItem);
txtListChild.setText(childText);
return convertView;
}
private int getItemId() {
int position = 0;
return position;
}
@Override
public int getChildrenCount(int groupPosition) {
return this._listDataChild.get(this._listDataHeader.get(groupPosition)).size();
}
@Override
public Object getGroup(int groupPosition) {
return this._listDataHeader.get(groupPosition);
}
@Override
public int getGroupCount() {
return this._listDataHeader.size();
}
@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
String headerTitle = (String) getGroup(groupPosition);
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) this._context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.list_group, null);
}
TextView lblListHeader = (TextView) convertView.findViewById(R.id.lblListHeader);
lblListHeader.setTypeface(null, Typeface.BOLD);
lblListHeader.setText(headerTitle);
return convertView;
}
@Override
public boolean hasStableIds() {
return false;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
}
main activity.Java
public class MainActivity extends ProfileActivity {
ExpandableListAdapter listAdapter;
ExpandableListView expListView;
List<String> listDataHeader;
HashMap<String, List<String>> listDataChild;
private ProgressDialog mprocessingdialog;
private static String url = "http://www.wishlist.feichter.co.uk/android/present_list.php";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mprocessingdialog = new ProgressDialog(this);
// get the listview
expListView = (ExpandableListView) findViewById(R.id.lvExp);
// preparing list data
new DownloadJason().execute();
}
/*
* Preparing the list data
*/
private class DownloadJason extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
//Showing Progress dialog
mprocessingdialog.setTitle("Please Wait..");
mprocessingdialog.setMessage("Loading");
mprocessingdialog.setCancelable(false);
mprocessingdialog.setIndeterminate(false);
mprocessingdialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
// TODO Auto-generated method stub
JSONParser jp = new JSONParser();
String jsonstr = jp.makeServiceCall(url);
Log.d("Response = ", jsonstr);
if (jsonstr != null) {
// For Header title Arraylist
listDataHeader = new ArrayList<String>();
// Hashmap for child data key = header title and value = Arraylist (child data)
listDataChild = new HashMap<String, List<String>>();
try {
JSONObject jobj = new JSONObject(jsonstr);
JSONArray jarray = jobj.getJSONArray("presents_db");
for (int hk = 0; hk < jarray.length(); hk++) {
JSONObject d = jarray.getJSONObject(hk);
// Adding Header data
//listDataHeader.add(d.getString("name"));
listDataHeader.add(d.getString("name") + "'s presents are: ");
// Adding child data for lease offer
List<String> members = new ArrayList<String>();
//members.add(d.getString("name") + "'s presents are: ");
JSONArray xarray = d.getJSONArray("presents_list");
for (int i = 0; i < xarray.length(); i++) {
JSONObject a = xarray.getJSONObject(i);
if("".equals(a.getString("bought_by"))) {
members.add(a.getString("present"));
//members.add(System.getProperty("line.separator"));
//ExpandableListAdapter hello = new test(this);
//hello.execute();
//View b = findViewById(R.id.BtnToClick);
//Button b = findViewById(R.id.BtnToClick);
//b.setVisibility(View.VISIBLE);
}else{
members.add(a.getString("present") + "\r\n bought by: " + a.getString("bought_by"));
}
}
// Header into Child data
listDataChild.put(listDataHeader.get(hk), members);
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} else {
Toast.makeText(getApplicationContext(),"Please Check internet Connection", Toast.LENGTH_SHORT).show();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
mprocessingdialog.dismiss();
//call constructor
listAdapter = new ExpandableListAdapter(getApplicationContext(), listDataHeader, listDataChild);
// setting list adapter
expListView.setAdapter(listAdapter);
}
}
}
正如您所看到的，if("".equals(a.getString("bought_by"))) {函数会更改孩子显示的内容，但是，如何添加按钮？
我知道它必须是一种完全不同的方法......
任何帮助非常感谢！
在child_layout中添加按钮，使按钮的可见性“消失”。在getChildView（）中，检查是否已购买礼物并使按钮可见，在其他情况下，使按钮可见性“消失”。