android delete file using context menu

问题

I've got a Listview showing files currently on the SDcard. When you long press the file, a context menu pops up.

My question is: how do I pass in the selected item to the Context Menu in order to delete the file from the list, and is it possible to also delete it from the SDcard using this? My Code is as follows:

    public class PlayListActivity extends ListActivity {
// Songs list
public ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.playlist);

    ArrayList<HashMap<String, String>> songsListData = new ArrayList<HashMap<String, String>>();

    SongsManager plm = new SongsManager();
    // get all songs from sdcard
    this.songsList = plm.getPlayList();

    // looping through playlist
    for (int i = 0; i < songsList.size(); i++) {
        // creating new HashMap
        HashMap<String, String> song = songsList.get(i);

        // adding HashList to ArrayList
        songsListData.add(song);
    }

    // Adding menuItems to ListView
    ListAdapter adapter = new SimpleAdapter(this, songsListData,
            R.layout.playlist_item, new String[] { "songTitle", "songDate" }, new int[] {
                    R.id.songTitle, R.id.songDate });

    setListAdapter(adapter);
    // setup ListView item
    ListView lv = getListView();
    registerForContextMenu(lv);
    notifyDataSetChanged();
    // listening to single listitem click
    lv.setOnItemClickListener(new OnItemClickListener() {

        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {

            // getting listitem index
            int songIndex = position;
            // Starting new intent
            Intent in = new Intent(getApplicationContext(),
                    Bandboxstage.class);
            // Sending songIndex to PlayerActivity
            in.putExtra("songIndex", songIndex);
            setResult(100, in);
            // Closing PlayListView
            finish();
        }
    }); 
}


private void notifyDataSetChanged() {
    // TODO Auto-generated method stub

}


@Override
public void onCreateContextMenu(ContextMenu menu, View v,
        ContextMenuInfo menuInfo) {
    // TODO Auto-generated method stub
    super.onCreateContextMenu(menu, v, menuInfo);
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.context_menu, menu);
}


@Override
public boolean onContextItemSelected(MenuItem item) {
    AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();

    switch (item.getItemId()) {
    case R.id.delete: 
        Toast.makeText(this, "Delete Called.", Toast.LENGTH_SHORT).show();
        deleteFile(info.id);

        return true;
    case R.id.share:
        Toast.makeText(this, "Share Called.", Toast.LENGTH_SHORT).show();

        default:
            return super.onContextItemSelected(item);
    }
}


private void deleteFile(long id) {
    // TODO Auto-generated method stub

}

}

回答1:

Well your answer is in your implementation itself. If you notice, in your onContextItemSelected() , the following statement brings in the info of the item you have selected in your main listview.

AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();

You can use info.position to find out the position of your item in the list and then get the object from your ArrayList using songsList.get(info.position).

@Override
public boolean onContextItemSelected(MenuItem item) {
    AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();

    switch (item.getItemId()) {
    case R.id.delete: 
        Toast.makeText(this, "Delete Called.", Toast.LENGTH_SHORT).show();
        //Make sure songsList is a global variable so that it can be accessed here.
        HashMap<String, String> song = songsList.get(info.position);
        //Call your delete function to delete the song.

        return true;
    case R.id.share:
        Toast.makeText(this, "Share Called.", Toast.LENGTH_SHORT).show();

        default:
            return super.onContextItemSelected(item);
    }
}

回答2:

Refer this LINK it passes varialble on long click.

below is the deletefile function

file.delete() will delete the file.

来源：https://stackoverflow.com/questions/10265303/android-delete-file-using-context-menu