Delete selected row in list in android
I have a listview with a custom row that has a text view and a clickable image to delete the row. Listview gets data from sqlite database. I have successfully loaded data from database to list. I want to delete this row from the database when the delete button is clicked. I know it requires binding an onclick event handler to the delete button and getting the object or sqlite data associated with the string. How can I get the sqlite data associated with the row the user clicked on the delete button on? Here is my adapter in listview
public class CommentAdapter extends ArrayAdapter<Comment> {
// private objects
private List<Comment> mListComment;
private LayoutInflater mInflater;
public CommentAdapter(Context c,int textViewResourceId, List<Comment> list) {
super(c, textViewResourceId, list);
mListComment = list;
// create layout inflater
mInflater = LayoutInflater.from(c);
}
@Override
public int getCount() {
return mListComment.size();
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// get view reference
View view = convertView;
// if null
if(view == null) {
// inflate new layout
view = mInflater.inflate(R.layout.comment_row, null);
// create a holder
ViewHolder holder = new ViewHolder();
// find controls
holder.txtComment = (TextView)view.findViewById(R.id.txtComment);
holder.btnDelete = (ImageView)view.findViewById(R.id.btnDelete);
// set data structure to view
view.setTag(holder);
}
Comment cmt = mListComment.get(position);
// if not null
if(cmt != null) {
// query data structure
ViewHolder holder = (ViewHolder)view.getTag();
// set data to display
holder.txtComment.setText(cmt.getComment());
holder.btnDelete.setClickable(true);
holder.btnDelete.setImageResource(android.R.drawable.ic_delete);
}
// return view
return view;
}
/*
* @class ViewHolder
* to hold data structure on view with comment info
*/
static class ViewHolder {
private TextView txtComment;
private ImageView btnDelete;
}
}
Here is my CommentsDataSource class
public class CommentsDataSource {
private SQLiteDatabase database;
private DatabaseHelper dbHelper;
private String[] allColumns = { DatabaseHelper.COLUMN_ID, DatabaseHelper.COLUMN_COMMENT };
public CommentsDataSource(Context context) {
dbHelper = new DatabaseHelper(context);
}
public void open() throws SQLException {
database = dbHelper.getWritableDatabase();
}
public void close() {
dbHelper.close();
}
public Comment createComment(String comment) {
//insert into databasae
return newComment;
}
private Comment cursorToComment(Cursor cursor) {
//convert cursor to comment
return comment;
}
public void deleteComment(Comment comment) {
//delete row from datbase
}
public List<Comment> getAllComments() {
//get all rows
return comments;
}
}
source to share
Change the getView method as shown below:
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// get view reference
View view = convertView;
// if null
if(view == null) {
// inflate new layout
view = mInflater.inflate(R.layout.comment_row, null);
// create a holder
ViewHolder holder = new ViewHolder();
// find controls
holder.txtComment = (TextView)view.findViewById(R.id.txtComment);
holder.btnDelete = (ImageView)view.findViewById(R.id.btnDelete);
// set data structure to view
view.setTag(holder);
}
final Comment cmt = mListComment.get(position);
// if not null
if(cmt != null) {
// query data structure
ViewHolder holder = (ViewHolder)view.getTag();
// set data to display
holder.txtComment.setText(cmt.getComment());
holder.btnDelete.setClickable(true);
holder.btnDelete.setImageResource(android.R.drawable.ic_delete);
holder.btnDelete.setOnClickListener(new View.OnClickListener(){
public void onClick(View view)
{
commentsDataSource.deleteComment(cmt);
//Requery DB to get Updated results
notifyDataSetChanged();
}
})
}
// return view
return view;
}
source to share
You need to install onlistitemclicklistener
to advanced ListActivity
. It will be something like this.
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
ViewHolder item = (ViewHolder ) getListAdapter().getItem(position);
Toast.makeText(this, item.txtComment + " selected", Toast.LENGTH_LONG).show();
}
Now make a handler to delete the selected row. You have listview
, current view
and indexed id
. Hope it works
source to share
write a listener for button click and in onClick () method, use this code:
@Override
protected void onClick(View view){
view.getParent().setVisibility(View.GONE);
}
I hope this works for you. Alternatively, since I don't have time to test the above code, if that doesn't work, in the method getView()
you can keep view
and the button two separate ArrayList
, then get the button's index in onClick()
, using the button, ArrayList
and set the visibility of the same index in the view ArrayList
as GONE
. This method is messy, so I prefer the above method.
source to share