我正在使用listview制作NLevel可扩展列表。我在列表视图中添加了仅复选框的最后一级数据。我陷入了下面的情况。
如果我选中复选框，那么当我展开listview时，复选框会自动取消选中。我不希望它像那样。如果我选中了复选框，它应保持检查状态，直到我手动取消选中。
请有人帮帮我!!我被困在这里已经两天了。
这是我的代码：
MainActivity.java
public class MainActivity extends Activity {
List<NLevelItem> list;
ListView listView;
Context context;
Button checkButton;
ArrayList<String>tempList;
CheckBox selected = null; //Make only one selection at a time
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.listView1);
list = new ArrayList<NLevelItem>();
context = this;
checkButton = (Button)findViewById(R.id.buttons);
tempList = new ArrayList<String>();
//here we create 5 grandparent (top level) NLevelItems
//then foreach grandparent create a random number of parent (second level) NLevelItems
//then foreach parent create a random number of children (third level) NLevelItems
//we pass in an anonymous instance of NLevelView to the NLevelItem, this NLevelView is
//what supplies the NLevelAdapter with a View for this NLevelItem
Random rng = new Random();
final LayoutInflater inflater = LayoutInflater.from(this);
for (int i = 0; i < 5; i++) {
final NLevelItem grandParent = new NLevelItem(new SomeObject("GrandParent "+i),null, new NLevelView() {
@Override
public View getView(NLevelItem item) {
View view = inflater.inflate(R.layout.list_item, null);
TextView tv = (TextView) view.findViewById(R.id.textView);
//tv.setBackgroundColor(Color.GREEN);
String name = (String) ((SomeObject) item.getWrappedObject()).getName();
tv.setText(name);
return view;
}
});
list.add(grandParent);
int numChildren = rng.nextInt(4) + 1;
for (int j = 0; j < numChildren; j++) {
NLevelItem parent = new NLevelItem(new SomeObject("Parent "+j),grandParent, new NLevelView() {
@Override
public View getView(NLevelItem item) {
View view = inflater.inflate(R.layout.list_item, null);
TextView tv = (TextView) view.findViewById(R.id.textView);
//tv.setBackgroundColor(Color.YELLOW);
String name = (String) ((SomeObject) item.getWrappedObject()).getName();
tv.setText(name);
return view;
}
});
list.add(parent);
int children = rng.nextInt(3)+1;
for(int x=0; x<children;x++){
final NLevelItem childs = new NLevelItem(new SomeObject("Parent1 "+x),parent, new NLevelView() {
@Override
public View getView(NLevelItem item) {
View view = inflater.inflate(R.layout.list_item, null);
TextView tv = (TextView) view.findViewById(R.id.textView);
//tv.setBackgroundColor(Color.BLUE);
String name = (String) ((SomeObject) item.getWrappedObject()).getName();
tv.setText(name);
return view;
}
});
list.add(childs);
int grandChildren = rng.nextInt(5)+1;
for( int k = 0; k < grandChildren; k++) {
NLevelItem child = new NLevelItem(new SomeObject("child "+k),childs, new NLevelView() {
@Override
public View getView(NLevelItem item) {
View view = inflater.inflate(R.layout.check_list, null);
TextView tv = (TextView) view.findViewById(R.id.checktextView);
final String name = (String) ((SomeObject) item.getWrappedObject()).getName();
final CheckBox checkBox = (CheckBox)view.findViewById(R.id.check);
checkBox.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(selected != null){ //Edit
selected.setChecked(false);
}
selected = checkBox; //Edit
if(checkBox.isChecked()){
tempList.add((String) ((SomeObject)childs.getWrappedObject()).getName()+"+"+name);
}
else {
tempList.remove((String) ((SomeObject)childs.getWrappedObject()).getName()+"+"+name);
}
}
});
//tv.setBackgroundColor(Color.GRAY);
tv.setText(name);
return view;
}
});
list.add(child);
}
}
}
}
NLevelAdapter adapter = new NLevelAdapter(list);
listView.setAdapter(adapter);
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
((NLevelAdapter)listView.getAdapter()).toggle(arg2);
((NLevelAdapter)listView.getAdapter()).getFilter().filter();
}
});
checkButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
for (int i=0;i<tempList.size();i++){
Toast.makeText(context,tempList.get(i),Toast.LENGTH_LONG).show();
}
}
});
}
class SomeObject {
public String name;
public SomeObject(String name) {
this.name = name;
}
public String getName() {
return name;
}
}
}
NLevelAdapter.java
public class NLevelAdapter extends BaseAdapter {
List<NLevelItem> list;
List<NLevelListItem> filtered;
public void setFiltered(ArrayList<NLevelListItem> filtered) {
this.filtered = filtered;
}
public NLevelAdapter(List<NLevelItem> list) {
this.list = list;
this.filtered = filterItems();
}
@Override
public int getCount() {
return filtered.size();
}
@Override
public NLevelListItem getItem(int arg0) {
return filtered.get(arg0);
}
@Override
public long getItemId(int arg0) {
return 0;
}
@Override
public View getView(int arg0, View arg1, ViewGroup arg2) {
return getItem(arg0).getView();
}
public NLevelFilter getFilter() {
return new NLevelFilter();
}
class NLevelFilter {
public void filter() {
new AsyncFilter().execute();
}
class AsyncFilter extends AsyncTask<Void, Void, ArrayList<NLevelListItem> > {
@Override
protected ArrayList<NLevelListItem> doInBackground(Void...arg0) {
return (ArrayList<NLevelListItem>)filterItems();
}
@Override
protected void onPostExecute(ArrayList<NLevelListItem> result) {
setFiltered(result);
NLevelAdapter.this.notifyDataSetChanged();
}
}
}
public List<NLevelListItem> filterItems() {
List<NLevelListItem> tempfiltered = new ArrayList<NLevelListItem>();
OUTER: for (NLevelListItem item : list) {
//add expanded items and top level items
//if parent is null then its a top level item
if(item.getParent() == null) {
tempfiltered.add(item);
} else {
//go through each ancestor to make sure they are all expanded
NLevelListItem parent = item;
while ((parent = parent.getParent())!= null) {
if (!parent.isExpanded()) {
//one parent was not expanded
//skip the rest and continue the OUTER for loop
continue OUTER;
}
}
tempfiltered.add(item);
}
}
return tempfiltered;
}
public void toggle(int arg2) {
filtered.get(arg2).toggle();
}
}
提前致谢!!
答案 0 :(得分：0)
使用ViewHolder类来设置和获取这样的标记：
null希望这可能会有所帮助。
答案 1 :(得分：0)
我认为您需要将复选框状态存储在boolean（已选中），并在调用getView()时在视图中反映出来。
1-添加布尔检查到NLevelItem：
private boolean checked = false;
//add setter: setChecked(boolean)
//add getter isChecked()
2-在getView()中使用该布尔值（添加复选框的最后一个）
@Override
public View getView(final NLevelItem item) {
// .......
final CheckBox checkBox = (CheckBox)view.findViewById(R.id.check);
checkBox.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//store checkbox state, note that NLevelItem item might need to be defined with 'final'
item.setChecked(checkBox.isChecked());
if(checkBox.isChecked()){
tempList.add((String) ((SomeObject)childs.getWrappedObject()).getName()+"+"+name);
}
else {
tempList.remove((String) ((SomeObject)childs.getWrappedObject()).getName()+"+"+name);
}
}//onClick()
}//setOnClickListener()
//update checkbox state from the corresponding NLevelItem
checkBox.setChecked(item.isChecked());
//.......
}//getView()
<强> - 编辑：
要选择1项，您需要迭代所有项目，设置checked = false，但是1 我不确定你是否必须这样做：
List<NLevelItem> list;
或
List<NLevelListItem> filtered;
在适配器类
中private void selectOnly(int position){
for(int a=0;a<list.size();a++){
if(a == position){
list.get(a).setChecked(true);
continue;
}
list.get(a).setChecked(false);
}//for loop
notifyDataSetChanged(); // to update views (checkbox state)
}
用法：selectOnly(15);