我有一个包含 12 个项目的 ListView,每个项目包含一个 TextView 和一个复选框。我设法使 CheckBox 检查状态保持不变,这样当我上下滚动时,我不会丢失为每个 CheckBox 设置的检查状态。
我现在面临的问题是,对于 ListView 中的每个项目,如果选中其对应的 CheckBox,我想将 TextView 添加到 ArrayList,如果未选中相应的 CheckBox,我应该从 ArrayList 中删除 TextView,如果它包含在里面。
在 getView() 方法的以下代码中,行“Log.d(TAG,”chosen topic size: “+ selectedTopics.size());” 总是返回零??!!
请帮我解决这个问题。
获取视图():
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
View view = null;
if (convertView == null) {
LayoutInflater layoutinflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
view = layoutinflater.inflate(R.layout.list_items_layout, null);
final ViewHolder holder = new ViewHolder();
holder.tv = (TextView) view.findViewById(R.id.tvlist_topic);
holder.cb = (CheckBox) view.findViewById(R.id.cbList_hook);
holder.iv = (ImageView) view.findViewById(R.id.ivList_delete);
holder.cb.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
// TODO Auto-generated method stub
ItemDesign element = (ItemDesign) holder.cb.getTag();
element.setChecked(buttonView.isChecked());
if(element.isChecked()) {
if (!chosenTopics.contains(designList.get(position).getTopic()))
chosenTopics.add(designList.get(position).getTopic());
}
if (!element.isChecked()) {
if (!chosenTopics.isEmpty()) {
if (chosenTopics.contains(designList.get(position).getTopic()))
chosenTopics.remove(position);
}
}
}
});
Log.d(TAG, "chosen topic size: " + chosenTopics.size());
view.setTag(holder);
holder.cb.setTag(designList.get(position));
} else {
view = convertView;
((ViewHolder) view.getTag()).cb.setTag(designList.get(position));
}
final ViewHolder holder = (ViewHolder) view.getTag();
holder.tv.setText(designList.get(position).getTopic());
holder.cb.setChecked(designList.get(position).isChecked());
holder.iv.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (holder.cb.isChecked())
holder.cb.setChecked(false);
designList.remove(position);
notifyDataSetChanged();
}
});
return view;
}
将 ArrayList 的初始化移动到构造函数后出现 LogCat 错误:
02-12 14:40:14.117: E/AndroidRuntime(22500): FATAL EXCEPTION: main
02-12 14:40:14.117: E/AndroidRuntime(22500): Process:
com.example.mqtt_designlayout_02, PID: 22500
02-12 14:40:14.117: E/AndroidRuntime(22500):
java.lang.IndexOutOfBoundsException: Invalid index 1, size is 1
02-12 14:40:14.117: E/AndroidRuntime(22500): at
java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
02-12 14:40:14.117: E/AndroidRuntime(22500): at
java.util.ArrayList.remove(ArrayList.java:403)
02-12 14:40:14.117: E/AndroidRuntime(22500): at
com.example.mqtt_designlayout_02.listviewadapter.ListViewAdapter$1.onCheckedChanged(ListViewAdapter.java:95)