i have a created an android app with a recyclerview. each row in the recyclerview has 3 textviews and an edittext. the data is added to the recyclerview from a dialogfragment list that i created. i liked to implement a delete when swiped method to my recyclerview and it worked, but not perfectly. the thing is that when i first add items from the list and then swipe to delete, the swiping works and the recyclerview is updated. but when i add items to the recyclerview, then open my list and add new items to my recyclerview, the swiping doesn't work properly. i tried to understand what the problem is but i couldn't figure it out. i made a work around solution but i'm not satisfied with it. i'll show you my codes:
this is my dialog fragment for the list
public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View view = inflater.Inflate(Resource.Layout.list, container, false);
lst = view.FindViewById<ListView>(Resource.Id.list_options);
check = view.FindViewById<CheckBox>(Resource.Id.checkBox1);
title = view.FindViewById<TextView>(Resource.Id.spinnerTitle);
ok = view.FindViewById<Button>(Resource.Id.ok);
check.CheckedChange += delegate
{
if (check.Checked == true)
{
adp = new list_adapter(this, getmodel(true), check);
lst.Adapter = adp;
}
else
{
adp = new list_adapter(this, getmodel(false), check);
lst.Adapter = adp;
}
};
WSEng.WebService5 ws = new WSEng.WebService5();
ws.get_itemsAsync(1);
ws.get_itemsCompleted += Ws_get_itemsCompleted;
SearchView searchView1 = view.FindViewById<SearchView>(Resource.Id.searchView1);
searchView1.QueryTextChange += (s, e) =>
{
adp.Filter.InvokeFilter(e.NewText);
};
searchView1.QueryTextSubmit += (s, e) =>
{
// Handle enter/search button on keyboard here
Toast.MakeText(this.Context, "Searched for: " + e.Query, ToastLength.Short).Show();
e.Handled = true;
};
ok.Click += delegate
{
selectedItems.Clear();
selectedItems = adp.GetSelectedItems();
sendResult(0);
this.Dismiss();
};
return view;
}
public List<list_item> getmodel(bool selection)
{
List<list_item> after_selection = new List<list_item>();
for (int i=0;i<user.tableItems.Count;i++)
{
user.tableItems[i].IsSelected = selection;
after_selection.Add(user.tableItems[i]);
}
return after_selection;
}
private void Ws_get_itemsCompleted(object sender, WSEng.get_itemsCompletedEventArgs e)
{
try
{
DataTable laborers = new DataTable();
laborers = e.Result;
user.tableItems.Clear();
int i = 0;
foreach (DataRow row in laborers.Rows)
{
user.tableItems.Add(new list_item { id = i, name = row["ItemName"].ToString(), item_code = row["itemcode"].ToString(), unit = row["itemsunitcode"].ToString(), quantity = "1", itembarcode = row["itembarcode"].ToString(), categorycode = row["itemscategorycode"].ToString(), currentQty = row["currentQuantity"].ToString(), reference = row["reference"].ToString(), model = row["model"].ToString(), categoryname = row["categoryname"].ToString(), size = row["size"].ToString(), IsSelected = false });
i++;
}
adp = new list_adapter(this, user.tableItems, check);
lst.Adapter = adp;
}
catch (System.Reflection.TargetInvocationException exp)
{
System.Net.WebException exception = new System.Net.WebException("can't reach server", exp.InnerException);
Toast.MakeText(this.Context, exp.InnerException.Message, ToastLength.Long).Show();
Android.App.AlertDialog.Builder alert = new Android.App.AlertDialog.Builder(this.Context);
alert.SetTitle("Connection failed");
alert.SetMessage("Please, Check your Internet Connection!");
alert.SetPositiveButton("Retry", (senderAlert, args) =>
{
WSEng.WebService5 ws = new WSEng.WebService5();
ws.get_itemsAsync(1);
ws.get_itemsCompleted += Ws_get_itemsCompleted;
alert.Dispose();
});
_dialog = alert.Create();
_dialog.Show();
}
}
private void sendResult(int reqcode)
{
Intent intent = new Intent();
intent.PutExtra("result", JsonConvert.SerializeObject(selectedItems));
TargetFragment.OnActivityResult(TargetRequestCode, 0, intent);
}
private class SearchViewExpandListener : Java.Lang.Object, MenuItemCompat.IOnActionExpandListener
{
private readonly IFilterable _adapter;
public SearchViewExpandListener(IFilterable adapter)
{
_adapter = adapter;
}
public bool OnMenuItemActionCollapse(IMenuItem item)
{
_adapter.Filter.InvokeFilter("");
return true;
}
public bool OnMenuItemActionExpand(IMenuItem item)
{
return true;
}
}
}
}
this is the code of the fragment where my recyclerview is found. it is where i get the result of the selected items from the list fragment and fill them in the recyclerview
public override void OnActivityResult(int requestCode, int resultCode, Intent data)
{
if (requestCode == 0)
{
selected_data.AddRange( JsonConvert.DeserializeObject<List<list_item>>(data.GetStringExtra("result")));
laborers_dt.Clear();
int count_repeated = 0;
for (int i = 0; i < selected_data.Count; i++)
{
laborers_dt.Rows.Add(i + 1, selected_data[i].itembarcode, selected_data[i].item_code, selected_data[i].name, selected_data[i].unit, selected_data[i].quantity, selected_data[i].categorycode,"");
}
for (int i = 0; i < laborers_dt.Rows.Count; i++)
{
count_repeated = 0;
for (int j = 0; j < laborers_dt_total.Rows.Count; j++)
{
if (laborers_dt.Rows[i]["itemcode"].ToString() == laborers_dt_total.Rows[j]["itemcode"].ToString())
{
count_repeated = count_repeated + 1;
}
}
if (count_repeated == 0)
{
laborers_dt_total.Rows.Add(laborers_dt_total.Rows.Count + 1, laborers_dt.Rows[i]["itembarcode"].ToString(), laborers_dt.Rows[i]["itemcode"].ToString(), laborers_dt.Rows[i]["name"].ToString(), laborers_dt.Rows[i]["itemsunitcode"].ToString(),
Convert.ToDecimal(laborers_dt.Rows[i]["itemQty"].ToString()), laborers_dt.Rows[i]["itemscategorycode"].ToString(),"");
}
}
mLayoutManager = new LinearLayoutManager(this.Context);
mRecyclerView.HasFixedSize = true;
mRecyclerView.SetLayoutManager(mLayoutManager);
RecyclerviewAdapter = new recyclerviewAdapter(this, laborers_dt_total,selected_data);
mRecyclerView.SetAdapter(RecyclerviewAdapter);
var swipeHandler = new SwipeToDeleteCallback(0, ItemTouchHelper.Left, this.Context, RecyclerviewAdapter, laborers_dt_total,mRecyclerView);
var itemTouchHelper = new ItemTouchHelper(swipeHandler);
itemTouchHelper.AttachToRecyclerView(mRecyclerView);
}
}
public class recyclerview_viewholder : RecyclerView.ViewHolder
{
public TextView rownbr, itemname;
public EditText qty;
public TextView unit;
public LinearLayout linearLayout;
public recyclerview_viewholder(View itemView, Action<int> listener)
: base(itemView)
{
rownbr = itemView.FindViewById<TextView>(Resource.Id.rownbr);
itemname = itemView.FindViewById<TextView>(Resource.Id.laborname);
unit = itemView.FindViewById<TextView>(Resource.Id.days);
qty = itemView.FindViewById<EditText>(Resource.Id.overtime);
linearLayout = itemView.FindViewById<LinearLayout>(Resource.Id.linearLayout);
itemView.Click += (sender, e) => listener(base.LayoutPosition);
}
}
public class recyclerviewAdapter : RecyclerView.Adapter
{
// Event handler for item clicks:
public event EventHandler<int> ItemClick;
DataTable summary_Requests = new DataTable();
//Context context;
public readonly new_request_items context;
int selected_pos = -1;
private SwipeToDeleteCallback swipeToDeleteCallback;
List<list_item> item_details = new List<list_item>();
public recyclerviewAdapter(new_request_items context, DataTable sum_req, List<list_item> item_details)
{
this.context = context;
summary_Requests = sum_req;
this.item_details = item_details;
}
public recyclerviewAdapter(DataTable sum_req, SwipeToDeleteCallback swipeToDeleteCallback)
{
this.swipeToDeleteCallback = swipeToDeleteCallback;
summary_Requests = sum_req;
}
public override RecyclerView.ViewHolder
OnCreateViewHolder(ViewGroup parent, int viewType)
{
View itemView = LayoutInflater.From(parent.Context).
Inflate(Resource.Layout.recycler_view_request_new_data, parent, false);
recyclerview_viewholder vh = new recyclerview_viewholder(itemView, OnClick);
user.zero_val = new string[summary_Requests.Rows.Count];
vh.qty.TextChanged += (sender, e) =>
{
if (vh.qty.Text != "")
try
{
int position = vh.LayoutPosition;
summary_Requests.Rows[position]["itemQty"] = Convert.ToDecimal(vh.qty.Text);
user.zero_val[position]="Not_exist";
}
catch (System.FormatException exp)
{
int position = vh.LayoutPosition;
var icon = AppCompatResources.GetDrawable(context.Context, Resource.Drawable.error_ic);
icon.SetBounds(0, 0, 50, 50);
vh.qty.SetError("qty can be decimal", icon);
user.zero_val[position]="exits";
}
else if (vh.qty.Text == "")
{
int position = vh.LayoutPosition;
var icon = AppCompatResources.GetDrawable(context.Context, Resource.Drawable.error_ic);
icon.SetBounds(0, 0, 50, 50);
vh.qty.SetError("value can not be empty", icon);
user.zero_val[position]="exits";
}
};
vh.ItemView.LongClick += (sender, e) =>
{
int position = vh.AdapterPosition;
string itemcode = summary_Requests.Rows[position]["itemcode"].ToString();
list_item result = item_details.Find(list_item => list_item.item_code == itemcode);
Bundle bundle = new Bundle();
bundle.PutString("result", JsonConvert.SerializeObject(result));
items_info iteminf = new items_info();
iteminf.Arguments = bundle;
iteminf.Cancelable = true;
var SupportFragmentManager = this.context.FragmentManager;
iteminf.Show(SupportFragmentManager, "dialog");
selected_pos = position;
NotifyDataSetChanged();
};
return vh;
}
public override void
OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
recyclerview_viewholder vh = holder as recyclerview_viewholder;
vh.rownbr.Text = summary_Requests.Rows[position]["rowNumber"].ToString();
vh.itemname.Text = summary_Requests.Rows[position]["name"].ToString();
vh.unit.Text = summary_Requests.Rows[position]["itemsunitcode"].ToString();
vh.qty.Text= summary_Requests.Rows[position]["itemQty"].ToString();
if (selected_pos == position)
vh.ItemView.SetBackgroundColor(Color.ParseColor("#4fa5d5"));
else
vh.ItemView.SetBackgroundColor(Color.LightGray);
}
public void RemoveItem(int position)
{
if (laborers_dt_total.Rows.Count != 0)
{
if (position < laborers_dt_total.Rows.Count && position > -1)
{
laborers_dt_total.Rows.RemoveAt(position);
}
else
{
Toast.MakeText(context.Context, "select an item to delete", ToastLength.Long).Show();
}
}
else if (laborers_dt_total.Rows.Count == 0)
{
Toast.MakeText(context.Context, "no items to delete", ToastLength.Long).Show();
}
for (int i = 0; i < laborers_dt_total.Rows.Count; i++)
{
laborers_dt_total.Rows[i]["rowNumber"] = (i + 1).ToString();
NotifyDataSetChanged();
}
}
public DataTable get_dt_final()
{
DataTable final_dt = summary_Requests.Copy();
return final_dt;
}
public override int ItemCount
{
get { return summary_Requests.Rows.Count; }
}
// Raise an event when the item-click takes place:
void OnClick(int position)
{
if (ItemClick != null)
ItemClick(this, position);
// user.req_pos = position;
}
}
and this is the code of the swiping that is written in the same fragment, i'll show you the code before the work around and after it:
public class SwipeToDeleteCallback : ItemTouchHelper.SimpleCallback
{
private View v;
private DataTable dt;
private Context context;
public static RecyclerView.Adapter mAdapter;
private Android.Graphics.Drawables.Drawable deleteIcon;
private int intrinsicWidth;
private int intrinsicHeight;
private Android.Graphics.Drawables.ColorDrawable background;
private Color backgroundColor;
private Paint clearPaint;
private recyclerviewAdapter mdapter;
private RecyclerView rcv;
public SwipeToDeleteCallback(int dragDirs, int swipeDirs, Context context) : base(dragDirs, swipeDirs)
{
this.context = context;
deleteIcon = ContextCompat.GetDrawable(context, Resource.Drawable.delete_icon);
intrinsicWidth = 60;
intrinsicHeight = 60;
background = new Android.Graphics.Drawables.ColorDrawable();
backgroundColor = Color.ParseColor("#f44336");
clearPaint = new Paint();
clearPaint.SetXfermode(new PorterDuffXfermode(PorterDuff.Mode.Clear));
}
public SwipeToDeleteCallback(int dragDirs, int swipeDirs, Context context,recyclerviewAdapter mRecyclerView,DataTable dt,RecyclerView rcv) : this(dragDirs, swipeDirs, context)
{
this.context = context;
this.rcv = rcv;
this.mdapter = mRecyclerView;
this.dt = dt;
deleteIcon = ContextCompat.GetDrawable(context, Resource.Drawable.delete_icon);
intrinsicWidth = 60;
intrinsicHeight = 60;
background = new Android.Graphics.Drawables.ColorDrawable();
backgroundColor = Color.White;
clearPaint = new Paint();
clearPaint.SetXfermode(new PorterDuffXfermode(PorterDuff.Mode.Clear));
}
public override int GetMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder)
{
if (viewHolder.AdapterPosition == 10)
{
return 0;
}
return base.GetMovementFlags(recyclerView, viewHolder);
}
public override void OnChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, bool isCurrentlyActive)
{
base.OnChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
}
public override bool OnMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target)
{
//throw new NotImplementedException();
return false;
}
public override void OnChildDrawOver(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, bool isCurrentlyActive)
{
var itemView = viewHolder.ItemView;
var itemHeight = itemView.Bottom - itemView.Top;
var isCanceled = dX == 0f && !isCurrentlyActive;
if (isCanceled)
{
clearCanvas(c, itemView.Right + dX, (float)itemView.Top, (float)itemView.Right, (float)itemView.Bottom);
base.OnChildDrawOver(c, recyclerView
, viewHolder, dX, dY, actionState, isCurrentlyActive);
return;
}
background.Color = backgroundColor;
background.SetBounds(itemView.Right + (int)dX, itemView.Top, itemView.Right, itemView.Bottom);
background.Draw(c);
var deleteIconTop = itemView.Top + (itemHeight - intrinsicHeight) / 2;
var deleteIconMargin = (itemHeight - intrinsicHeight) / 2;
var deleteIconLeft = itemView.Right - deleteIconMargin - intrinsicWidth;
var deleteIconRight = itemView.Right - deleteIconMargin;
var deleteIconBottom = deleteIconTop + intrinsicHeight;
deleteIcon.SetBounds(deleteIconLeft, deleteIconTop, deleteIconRight, deleteIconBottom);
deleteIcon.Draw(c);
base.OnChildDrawOver(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
}
private void clearCanvas(Canvas c, float v, float top, float right, float bottom)
{
c.DrawRect(v, top, right, bottom, clearPaint);
}
public override void OnSwiped(RecyclerView.ViewHolder viewHolder, int direction)
{
mdapter.RemoveItem(viewHolder.AdapterPosition);
mdapter.NotifyDataSetChanged();
}
public override void ClearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder)
{
base.ClearView(recyclerView, viewHolder);
}
}
}
}
and this is the solution that i found:
public class SwipeToDeleteCallback : ItemTouchHelper.SimpleCallback
{
private View v;
private DataTable dt;
private Context context;
public static RecyclerView.Adapter mAdapter;
private Android.Graphics.Drawables.Drawable deleteIcon;
private int intrinsicWidth;
private int intrinsicHeight;
private Android.Graphics.Drawables.ColorDrawable background;
private Color backgroundColor;
private Paint clearPaint;
private recyclerviewAdapter mdapter;
private RecyclerView rcv;
public SwipeToDeleteCallback(int dragDirs, int swipeDirs, Context context) : base(dragDirs, swipeDirs)
{
this.context = context;
deleteIcon = ContextCompat.GetDrawable(context, Resource.Drawable.delete_icon);
intrinsicWidth = 60;
intrinsicHeight = 60;
background = new Android.Graphics.Drawables.ColorDrawable();
backgroundColor = Color.ParseColor("#f44336");
clearPaint = new Paint();
clearPaint.SetXfermode(new PorterDuffXfermode(PorterDuff.Mode.Clear));
}
public SwipeToDeleteCallback(int dragDirs, int swipeDirs, Context context,recyclerviewAdapter mRecyclerView,DataTable dt,RecyclerView rcv) : this(dragDirs, swipeDirs, context)
{
this.context = context;
this.rcv = rcv;
this.mdapter = mRecyclerView;
this.dt = dt;
deleteIcon = ContextCompat.GetDrawable(context, Resource.Drawable.delete_icon);
intrinsicWidth = 60;
intrinsicHeight = 60;
background = new Android.Graphics.Drawables.ColorDrawable();
backgroundColor = Color.White;
clearPaint = new Paint();
clearPaint.SetXfermode(new PorterDuffXfermode(PorterDuff.Mode.Clear));
}
public override int GetMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder)
{
if (viewHolder.AdapterPosition == 10)
{
return 0;
}
return base.GetMovementFlags(recyclerView, viewHolder);
}
public override void OnChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, bool isCurrentlyActive)
{
base.OnChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
}
public override bool OnMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target)
{
//throw new NotImplementedException();
return false;
}
public override void OnChildDrawOver(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, bool isCurrentlyActive)
{
var itemView = viewHolder.ItemView;
var itemHeight = itemView.Bottom - itemView.Top;
var isCanceled = dX == 0f && !isCurrentlyActive;
if (isCanceled)
{
clearCanvas(c, itemView.Right + dX, (float)itemView.Top, (float)itemView.Right, (float)itemView.Bottom);
base.OnChildDrawOver(c, recyclerView
, viewHolder, dX, dY, actionState, isCurrentlyActive);
return;
}
background.Color = backgroundColor;
background.SetBounds(itemView.Right + (int)dX, itemView.Top, itemView.Right, itemView.Bottom);
background.Draw(c);
var deleteIconTop = itemView.Top + (itemHeight - intrinsicHeight) / 2;
var deleteIconMargin = (itemHeight - intrinsicHeight) / 2;
var deleteIconLeft = itemView.Right - deleteIconMargin - intrinsicWidth;
var deleteIconRight = itemView.Right - deleteIconMargin;
var deleteIconBottom = deleteIconTop + intrinsicHeight;
deleteIcon.SetBounds(deleteIconLeft, deleteIconTop, deleteIconRight, deleteIconBottom);
deleteIcon.Draw(c);
base.OnChildDrawOver(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
}
private void clearCanvas(Canvas c, float v, float top, float right, float bottom)
{
c.DrawRect(v, top, right, bottom, clearPaint);
}
public override void OnSwiped(RecyclerView.ViewHolder viewHolder, int direction)
{
//Invoke Removing Item method from
int position = viewHolder.LayoutPosition;
mdapter.RemoveItem(viewHolder.AdapterPosition);
mdapter = new recyclerviewAdapter(myreq, laborers_dt_total, myreq.selected_data);
rcv.SetAdapter(mdapter);
var swipeHandler = new SwipeToDeleteCallback(0, ItemTouchHelper.Left, context, mdapter, laborers_dt_total, rcv);
var itemTouchHelper = new ItemTouchHelper(swipeHandler);
itemTouchHelper.AttachToRecyclerView(rcv);
}
public override void ClearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder)
{
base.ClearView(recyclerView, viewHolder);
}
}
}
}
i redefined the adapter for the recyclerview to work it out. i don't get it, why doesn't the mdapter.NotifyDataSetChanged(); work after i add new items. i am sorry for the long post. thanks in advance.
this is a link conveying my problem when i only use mdapter.NotifyDataSetChanged(); when i choose in the first time and delete rows. it works fine. but when i add new items and delete again, it doesn't. https://1drv.ms/v/s!ApO-CpoDPS4ikW3m0I_9X_pcmf8G?e=SZjH1v
