这是我想要调用startActionMode的适配器类。我在setActionMode方法中调用它但得到了这些错误：
无法从Context转换为ActivityFragment。
方法startActionMode（ActivityFragment.ActionModeCallback）未定义类型 ActivityFragment。
public class ListAdapter extends ArrayAdapter<ListGettersSetters>
{
ArrayList<ListGettersSetters> arrayListGettersSetters;
LayoutInflater layoutInflater;
Context context;
int Resource, i = 0, j = 0, checkedItemsCount = 0;
Animation animation1;
Animation animation2;
CheckBox flipCheckBox;
viewHolder holder;
ActionMode actionMode;
boolean isActionModeShowing;
static class viewHolder
{
public CheckBox imageView;
public TextView textViewName;
public TextView textViewData;
public TextView textViewDetails;
}
public ListAdapter(Context context, int resource, ArrayList<ListGettersSetters> arrayListGettersSetters)
{
super(context, resource, arrayListGettersSetters);
this.arrayListGettersSetters = arrayListGettersSetters;
Resource = resource;
this.context = context;
layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
animation1 = AnimationUtils.loadAnimation(context, R.anim.to_middle);
animation2 = AnimationUtils.loadAnimation(context, R.anim.from_middle);
isActionModeShowing = false;
}
@Override
public int getCount()
{
return arrayListGettersSetters.size();
}
@Override
public ListGettersSettersgetItem(int position)
{
return arrayListGettersSetters.get(position);
}
@Override
public long getItemId(int position)
{
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent)
{
holder = new viewHolder();
if(convertView == null)
{
convertView = layoutInflater.inflate(Resource, null);
holder.imageView = (CheckBox) convertView.findViewById(R.id.id_for_checkBox);
holder.textViewName = (TextView) convertView.findViewById(R.id.id_for_name_textView);
holder.textViewData = (TextView) convertView.findViewById(R.id.id_for_data_textView);
holder.textViewDetails = (TextView) convertView.findViewById(R.id.id_for_details_textView);
convertView.setTag(holder);
}
else
{
holder = (viewHolder) convertView.getTag();
}
holder.textViewName.setText(getItem(position).getName());
holder.textViewData.setText(getItem(position).getData());
holder.textViewDetails.setText(getItem(position).getDetails());
holder.imageView.setTag(position);
holder.imageView.setOnClickListener(new OnClickListener()
{
public void onClick(View view)
{
flipCheckBox = (CheckBox) view;
flipCheckBox.clearAnimation();
flipCheckBox.setAnimation(animation1);
flipCheckBox.startAnimation(animation1);
setAnimListners(arrayListGettersSetters.get(Integer.parseInt(view.getTag().toString())));
}
});
return convertView;
}
private void setAnimListners(final ListGettersSetters listGettersSetters)
{
AnimationListener animationListener = new AnimationListener()
{
@Override
public void onAnimationStart(Animation animation)
{
if (animation == animation1)
{
flipCheckBox.clearAnimation();
flipCheckBox.setAnimation(animation2);
flipCheckBox.startAnimation(animation2);
}
else
{
listGettersSetters.setIsChecked(!listGettersSetters.isChecked());
setCount();
setActionMode();
}
}
public void setCount()
{
if (listGettersSetters.isChecked())
{
checkedItemsCount++;
}
else
{
if (checkedItemsCount != 0)
{
checkedItemsCount--;
}
}
Log.v("Checked items count", checkedItemsCount + "");
}
private void setActionMode()
{
if (checkedItemsCount > 0)
{
if (!isActionModeShowing)
{
actionMode = ((ActivityFragment) context).startActionMode(new ActivityFragment.ActionModeCallback(context));
isActionModeShowing = true;
}
}
else if (actionMode != null)
{
actionMode.finish();
isActionModeShowing = false;
}
if (actionMode != null)
{
actionMode.setTitle(String.valueOf(checkedItemsCount));
}
notifyDataSetChanged();
}
@Override
public void onAnimationRepeat(Animation animation)
{
}
@Override
public void onAnimationEnd(Animation animation)
{
}
};
animation1.setAnimationListener(animationListener);
animation2.setAnimationListener(animationListener);
}
这是我的ActivityFragment类，我在其中实现了一个名为ActionModeCallback的类，该类在我的适配器类中调用。此外，当我在这个内部类中获取ActivityFragment的上下文时，也会得到相同的错误。
public class ActivityFragment extends ListFragment
{
@Override
public View onCreateView(LayoutInflater layoutInflater, ViewGroup viewGroup, Bundle savedInstanceState)
{
View view = layoutInflater.inflate(R.layout.folders_fragment_listview, null, false);
return view;
}
public static final class ActionModeCallback implements ActionMode.Callback
{
Context context;
public ActionModeCallback(Context context)
{
this.context = context;
}
@Override
public boolean onActionItemClicked(ActionMode actionMode, MenuItem menuItem)
{
Toast toast = null;
ArrayList<FoldersFragmentGettersSetters> selectedListItems = new ArrayList<FoldersFragmentGettersSetters>();
StringBuilder selectedItems = new StringBuilder();
for (FoldersFragmentGettersSetters foldersFragmentGettersSetters : ((ActivityFragment ) context).listAdapter.arrayListGettersSetters)
{
if (foldersFragmentGettersSetters.isChecked())
{
selectedListItems.add(foldersFragmentGettersSetters);
}
}
if (menuItem.getTitle().equals("Delete"))
{
toast = Toast.makeText(context, "Delete: " + selectedItems.toString(), Toast.LENGTH_SHORT);
}
else if (menuItem.getTitle().equals("Archive"))
{
toast = Toast.makeText(context, "Archive: " + selectedItems.toString(), Toast.LENGTH_SHORT);
}
else if (menuItem.getTitle().equals("Mark unread"))
{
toast = Toast.makeText(context, "Mark unread: " + selectedItems.toString(), Toast.LENGTH_SHORT);
}
else if (menuItem.getTitle().equals("Move"))
{
toast = Toast.makeText(context, "Move: " + selectedItems.toString(), Toast.LENGTH_SHORT);
}
else if (menuItem.getTitle().equals("Remove star"))
{
toast = Toast.makeText(context, "Remove star: " + selectedItems.toString(), Toast.LENGTH_SHORT);
}
if (toast != null)
{
toast.show();
}
actionMode.finish();
return true;
}
@Override
public boolean onCreateActionMode(ActionMode actionMode, Menu menu)
{
menu.add("Delete").setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
menu.add("Archive").setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
menu.add("Mark unread").setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
menu.add("Move").setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
menu.add("Remove star").setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
return true;
}
@Override
public void onDestroyActionMode(ActionMode actionMode)
{
((ActivityFragment ) context).inboxAdapter.checkedItemsCount = 0;
((ActivityFragment ) context).inboxAdapter.isActionModeShowing = false;
for (FoldersFragmentGettersSetters foldersFragmentGettersSettersItem : ((InboxFragment) context).inboxList)
{
foldersFragmentGettersSettersItem.setIsChecked(false);
}
((ActivityFragment ) context).listAdapter.notifyDataSetChanged();
Toast.makeText(context, "Action mode closed", Toast.LENGTH_SHORT).show();
}
@Override
public boolean onPrepareActionMode(ActionMode actionMode, Menu menu)
{
return false;
}
}
}
答案 0 :(得分：3)
从
修改ListAdapter的构造函数public ListAdapter(Context context, int resource, ArrayList<ListGettersSetters> arrayListGettersSetters)
到
public ListAdapter(ActivityFragment context, int resource, ArrayList<ListGettersSetters> arrayListGettersSetters)
答案 1 :(得分：2)
一种好的方法是使用回调。
startActionModeCallback。startActionModeCallback。ActivityFragment中创建适配器实例时，将其作为侦听器传递并在片段中实现其回调方法。希望对你有意义。你可以问我澄清一下。祝你好运！
示例
适配器类
public class ListAdapter extends ArrayAdapter<ListGettersSetters>
{
Interface StartActionInterface
{
public void startActionMode();
}
//declare other instance variables and add following
StartActionInterface startActionModeListener;
//change your constructor as:
public ListAdapter(Context context, int resource, ArrayList<ListGettersSetters> arrayListGettersSetters, StartActionInterface listener)
{
//normal code
startActionModeListener = listener;
}
}
<强> ActivityFragment
public class ActivityFragment extends ListFragment implements StartActionInterface
{
@Override
public View onCreateView(LayoutInflater layoutInflater, ViewGroup viewGroup, Bundle savedInstanceState)
{
View view = layoutInflater.inflate(R.layout.folders_fragment_listview, null, false);
////////initialize adapter and pass `this` in last argument
return view;
}
//Implement callback method. Also implement `setActionMode()` method here in fragment.
void startActionMode()
{
setActionMode();
}
}
在函数setActionMode()中，替换以下行：
if (!isActionModeShowing)
{
actionMode = ((ActivityFragment) context).startActionMode(new ActivityFragment.ActionModeCallback(context));
isActionModeShowing = true;
}
使用：
if (!isActionModeShowing)
{
actionMode = getActivity().startActionMode(new ActionModeCallback(getActivity()));
isActionModeShowing = true;
}