ObservableCollection don't Binding in CodeBehind - xamarin

Question

ObservableCollection don't Binding
Hello guys,
I need help in one question of ObservableCollection using in Xamarin Forms.
I need build one "Custom ListView" for TabIndex works correctly in my screen.
For this i create in code behind:
- ScrollView
- Label
- Entry
Screen rendering is works ok, only my problem is on binding in one ObservableCollection.
I my tests one property single string using OnPropertyChanged works correctly, but using ObservableCollection dont works. I tried using CollectionChanged but withour success.
Someone having same problem? Exist solution for this?
ViewModel:
private ObservableCollection<RawData> rawDataList;
public ObservableCollection<RawData> RawDataList
{
get { return rawDataList; }
set { rawDataList = value; OnPropertyChanged("RawDataList"); }
}
Code Behind
private void BuildRawDataTemplate()
{
var grid = BuildGrid();
#region Templates
grid.Children.Add(BuildScheduleHeaderTitleTemplate(), 0, 0); // Posição: Coluna: 0 | Linha: 0
grid.Children.Add(BuildScheduleDetailsSubtitleTemplate("Dados Brutos"), 0, 1); // Posição: Coluna: 0 | Linha: 1
#endregion
#region RawData
var scrollView = BuildScrollView();
var stackLayout = BuildStackLayout("DefaultLight", 10, StackOrientation.Vertical, null, LayoutOptions.Center);
rawDataCount = scheduleViewModel.RawDataList.Count();
foreach (var item in scheduleViewModel.RawDataList.Select((rawData, i) => new { i, rawData }))
{
stackLayout.Children.Add(GenerateLabel(item.rawData.Identification));
if (item.rawData.InfoTypeId == (int)InfoType.Equipment)
stackLayout.Children.Add(GenerateEquipmentsPicker(item.rawData, item.i, item.i == 0, rawDataCount == (item.i + 1)));
else
stackLayout.Children.Add(GenerateEntry(item.rawData, item.i, item.i == 0, rawDataCount == (item.i + 1)));
}
scrollView.Content = stackLayout;
grid.Children.Add(scrollView, 0, 2); // Posição: Coluna: 0 | Linha: 2
#endregion
#region Buttons
var stackLayoutFooterButtons = BuildStackLayout(string.Empty, null, StackOrientation.Horizontal, LayoutOptions.End, null);
stackLayoutFooterButtons.Children.Add(GeneratePrimaryButton("RESULTADOS", scheduleViewModel.VisibleResultCommand, rawDataCount++, scheduleViewModel.SelectedSampleBase.Finished));
stackLayoutFooterButtons.Children.Add(GeneratePrimaryButton("CALCULAR", scheduleViewModel.CalculateRawDataCommand, rawDataCount++, !scheduleViewModel.SelectedSampleBase.Synced));
stackLayoutFooterButtons.Children.Add(GeneratePrimaryButton("SALVAR", scheduleViewModel.SaveRawDataCommand, rawDataCount++, !scheduleViewModel.SelectedSampleBase.Synced));
grid.Children.Add(stackLayoutFooterButtons, 0, 3); // Posição: Coluna: 0 | Linha: 3
#endregion
Content = grid;
SetFocusOnFirstEntry();
}
private Entry GenerateEntry(RawData rawData, int tabIndex, bool firstElement = false, bool hasNextTabIndex = false)
{
var entry = new Entry();
entry.TabIndex = tabIndex;
entry.Text = rawData.DisplayValue;
entry.SetBinding(Entry.TextProperty, nameof(rawData.DisplayValue), BindingMode.TwoWay);
entry.StyleId = $"RawDataDynamicEntry_{tabIndex}";
entry.IsTabStop = true;
entry.IsEnabled = rawData.NotSynced;
if (rawData.InfoTypeId == (int)InfoType.Integer)
entry.Behaviors.Add(new NumericValidationBehavior());
if (firstElement)
entry.Focus();
// Temp
var focusOnReturnBehavior = new FocusOnReturnBehavior();
focusOnReturnBehavior.HasNextTabIndex = hasNextTabIndex;
entry.Behaviors.Add(focusOnReturnBehavior);
return entry;
}

Answer 1

I am little confused by the question. But I believe you have problem adding the entries to listview. Your Observable collection data is not getting populated in Listview.
I wrote a post on creating multiselect listview. You just see how I'm creating a listview and binding the contents of observable collection to it.
Please see here: https://androidwithashray.blogspot.com/2018/03/multiselect-list-view-using-xamarin.html
Please note for listview, you don't need scrollview as listview auto scrolls if the contents are more to fit inside the screen.
Hope this helps!!

Answer 2

For resolve my problem i using:
Code-Behind
#region Events Changed
private void EntryTextChanged(object sender, TextChangedEventArgs e)
{
var entryChanged = (Entry)sender;
selectedRawData.DisplayValue = entryChanged.Text;
}
private void PickerSelectedIndexChanged(object sender, System.EventArgs e)
{
var pickerChanged = (Picker)sender;
selectedRawData.DisplayValue = selectedItem.Identification;
}
#endregion