如何从ListView项在对话框上显示自定义消息

Question

我正在通过单击ListView中的项来寻求在对话框上显示消息的帮助。示例：

Answer 1

perhaps a bit more detail(code snippet) could be helpful here to response to your query. But I am going to provide a generalized solution here.

On the activity/fragment you initialized your list view, you can use listviews setOnItemClickListener method and override the AdapterViews onItemClick method to get your list item position:

       listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {

                /*listAdapter is the adapter for your listView and ListItem 
                represents individual item model for the list*/

                ListItem listItem= listAdapter.getItem(i); 
                if(listItem!=null){
                    //show your dialog message according to listItem here
                }

            }
        });

Answer 2

If you are using some adapter to populate your list view

public class DemoListView extends AppCompatActivity implements ListAdapter.PlaceClickInterface {

    ListView listView ;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_demo_list);

        List<String> places = new ArrayList<>(Arrays.asList("New york","washington","london"));
        listView = (ListView)findViewById(R.id.list_view_demo);
        ListAdapter adapter = new ListAdapter(places , this) ;
        listView.setAdapter(adapter);
    }


    @Override
    public void onPlaceClick(int position) {
        Log.v("DemoListView" , "position : "+position) ;
        //show dialog here with Alert dialog builder or ListFragment class with custom UI
    }
}

Extend list adapters like ArrayAdapter or BaseAdapter :

In this adapter , create an Interface that can be implemented in the Activity(DemoListView ) in which you want to show the dialog box .

In the implemented method onPlaceClick() in DemoListView create and show the dialog box

public class ListAdapter extends BaseAdapter{

    List<String> mPlaces ;
    Context mContext ;
    LayoutInflater mInflater ;
    PlaceClickInterface mPlaceClickInterface;

    public ListAdapter( List places , DemoListView demoListView) {
        this.mContext = demoListView.getBaseContext() ;
        this.mPlaces = places ;
        this.mInflater =(LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        this.mPlaceClickInterface = (PlaceClickInterface) demoListView;
    }

    @Override
    public int getCount() {
        return mPlaces.size();
    }

    @Override
    public Object getItem(int position) {
        return mPlaces.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.item_list_data, parent, false);
            holder = new ViewHolder(convertView);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }
        holder.bind(holder ,position);
        return convertView ;
    }

    private class ViewHolder{

        TextView places ;
        ViewHolder(View view){
            this.places = (TextView) view.findViewById(R.id.list_place);
        }
        // used to populate the list with list item and attach click listener on each item
        void bind(ViewHolder holder ,final int position){
            holder.places.setText(mPlaces.get(position));
            holder.places.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    mPlaceClickInterface.onPlaceClick(position);
                }
            });
        }
    }

    public interface PlaceClickInterface {
        void onPlaceClick(int position) ;
    }
}