问题
I have list view [text view and check box controlls] with more data. I will choose the item from list view and display the selected items in the next activity. My problem is, for the example if I choose 20th and 25th item in the list view it will display some other items in the next activity. That is list view position is getting changed when scrolling.
i am choosing an item by clicking the check box on the item. in the checkbox.setOnChanged listener i wrote code for which position is selected or not. if i choose 25th item and scroll the list view, the getview method is called and the checkbox.setonChanged method is change the selected position. I print the logcat at last.
My coding format:
public class ListContact extends ListActivity {
public void onCreate(Bundle icicle){
.....
ArrayAdapter<Model> adapter = new MyCustomArrayAdapter(this,getModel());
setListAdapter(adapter);
}
....
private List<Model> getModel() {
List<Model> list = new ArrayList<Model>();
Iterator<String> itr = constant.selectname.iterator();
while (itr.hasNext()) {
list.add(get(itr.next().toString()));
}
return list;
}
private Model get(String s) {
return new Model(s);
}
}
MyCustomArrayAdapter.java:
public class MyCustomArrayAdapter extends ArrayAdapter<Model> {
private final List<Model> list;
private final Activity context;
constant con ;
public MyCustomArrayAdapter(Activity context, List<Model> list) {
super(context, R.layout.list_layout, list);
this.context = context;
this.list = list;
}
static class ViewHolder {
protected TextView text;
protected CheckBox checkbox;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
// Log.e("getview", "getview");
View view = null;
if (convertView == null) {
LayoutInflater inflator = context.getLayoutInflater();
view = inflator.inflate(R.layout.list_layout, null);
final ViewHolder viewHolder = new ViewHolder();
viewHolder.text = (TextView) view.findViewById(R.id.label);
viewHolder.checkbox = (CheckBox) view.findViewById(R.id.check);
viewHolder.checkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
// con = new constant();
Model element = (Model) viewHolder.checkbox.getTag();
element.setSelected(buttonView.isChecked());
// Log.e("MyCustomArrayAdapter.java", "selectpos array list length"+constant.selectpos.size());
if(isChecked==true){
Log.e("check box value and position ", element.getName());
Log.e("position", ""+position);
con.selectpos.set(position, 1);
}
else{
Log.e("position unselect", ""+position +"---------"+ element.getName());
con.selectpos.set(position, 0);
}
}
});
view.setTag(viewHolder);
viewHolder.checkbox.setTag(list.get(position));
} else {
view = convertView;
((ViewHolder) view.getTag()).checkbox.setTag(list.get(position));
}
ViewHolder holder = (ViewHolder) view.getTag();
holder.text.setText(list.get(position).getName());
holder.checkbox.setChecked(list.get(position).isSelected());
return view;
}
}
logcat result:
02-08 10:44:28.142: E/check box value and position(293): AAAA Qqq
02-08 10:44:28.142: E/check box value and position(293): Mobile-123
02-08 10:44:28.152: E/position(293): 0
**after scrolling the list view some other item print 0th position unselected and wrong data:**
02-08 10:44:31.962: E/position unselect(293): 0---------F212
02-08 10:44:31.962: E/position unselect(293): Home-232
回答1:
I solved the problem. i add the
View view = null;
convertView = null; //in the get view and comments the else part of
if (convertView == null) {
}
/*else{
} */
回答2:
I would recommend you to remodify your getView like this. This helped me.
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
ViewHolder holder =null;
// Log.e("getview", "getview");
View view = null;
if (convertView == null) {
LayoutInflater inflator = context.getLayoutInflater();
view = inflator.inflate(R.layout.list_layout, null);
holder =(ViewHolder) view.getTag();
viewHolder.text = (TextView) view.findViewById(R.id.label);
viewHolder.checkbox = (CheckBox) view.findViewById(R.id.check);
view.setTag(viewHolder);
} else {
view = convertView;
((ViewHolder) view.getTag()).checkbox.setTag(list.get(position));
}
viewHolder.checkbox.setTag(list.get(position));
holder.text.setText(list.get(position).getName());
holder.checkbox.setChecked(list.get(position).isSelected());
viewHolder.checkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
// con = new constant();
Model element = (Model) viewHolder.checkbox.getTag();
element.setSelected(buttonView.isChecked());
// Log.e("MyCustomArrayAdapter.java", "selectpos array list length"+constant.selectpos.size());
if(isChecked==true){
Log.e("check box value and position ", element.getName());
Log.e("position", ""+position);
con.selectpos.set(position, 1);
}
else{
Log.e("position unselect", ""+position +"---------"+ element.getName());
con.selectpos.set(position, 0);
}
}
});
return view;
}
}
回答3:
change this in your adapter class
View view = null;
to
View view = convertView;
来源：https://stackoverflow.com/questions/9188201/list-view-position-is-getting-changed-when-scrolling-on-android