xamarin checkbox inside listview visibility change - xamarin.forms

Question

I have xamarin.forms app which contains a List view. I implemented a long press gesture for view cell of list view. Which works fine.What I am trying to do is, inside my list view there is a checkbox and its visibility property is set bind to data model. Defaultly it will be false. If I long pressed the view cell I want all checkbox to be visible.My purpose is multi select the list view.How can I accomplish that?
My data model
public class TimeSheetListData
{
public string StartDate { get; set; }
public string EndDate { get; set; }
public bool Selected { get; set; }
public bool IsCheckBoxVisible { get; set; }
}
I am simply setting the API data to the item source of listview.
ObservableCollection<TimeSheetListData> resultObjForApprovedTimeSheetList = new ObservableCollection<TimeSheetListData>();
After API call,
TimesheetListView.ItemsSource = resultObjForApprovedTimeSheetList;
My Longpress Event and changing the chekbox visiblility.
private void CustomView_LongPressEvent(object sender, EventArgs e)
{
foreach (TimeSheetListData TS in resultObjForApprovedTimeSheetList)
{
TSData.IsCheckBoxVisible = true;
}
TimesheetListView.ItemsSource = null;
TimesheetListView.ItemsSource = resultObjForApprovedTimeSheetList
}
It will change the visiblity of checkbox to true. But it will only visible when listview scrolled.
How can I solve this?

Answer 1

You need to implement INotifyPropertyChanged interface so that we could update the UI in runtime.
model
public class TimeSheetListData: INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
public string StartDate { get; set; }
public string EndDate { get; set; }
private bool selected;
public bool Selected {
get
{
return selected;
}
set
{
if (value!= null)
{
selected = value;
NotifyPropertyChanged("Selected");
}
}
}
private bool isCheckBoxVisible;
public bool IsCheckBoxVisible
{
get
{
return isCheckBoxVisible;
}
set
{
if (value != null)
{
isCheckBoxVisible = value;
NotifyPropertyChanged("IsCheckBoxVisible");
}
}
}
}