BindingMode=TwoWay in codebehind - xamarin.forms

Question

Edit: apologies for the bad title, apparently something like "Setting bindingmode in code behind" didn't fit the highly nebulous requirements of SO. A title that is clearly more obvious than what the current one is.
Original: I am trying to set the binding of my listview in the code behind of its data selector template. The reason i am doing this, as I suspect (because doing something similar to it in a different template selector fixed it) that once you exit that page android seems to still contain a reference to it and then throws a amarin.forms.platform.android.viewcellrendererA disposed object exception.
my current xaml looks as follows:
<StackLayout Orientation="Vertical"
Padding="0, 20, 0, 0"
HorizontalOptions="FillAndExpand"
VerticalOptions="StartAndExpand">
<Label
x:Name="LabelName"
FontAttributes="Bold"
TextColor="Black"
FontSize="14"
VerticalOptions="Start"
HorizontalOptions="FillAndExpand"/>
<ListView x:Name="MultiselectList"
SeparatorVisibility="None"
RowHeight="30"
Margin="0, 10, 0, 0"
VerticalOptions="FillAndExpand"
HorizontalOptions="StartAndExpand"
SelectedItem="{Binding SelectedItem, Mode=TwoWay}">
<ListView.ItemTemplate>
<DataTemplate>
<customcontrols:NoHighlightCell>
<StackLayout Orientation="Horizontal"
HorizontalOptions="FillAndExpand"
VerticalOptions="StartAndExpand">
<Image
x:Name="image"
Source="{Binding ImageUrl}"
VerticalOptions="StartAndExpand"
HorizontalOptions="Start"
Margin="0, 2, 0, 0"
WidthRequest="15"
HeightRequest="15" />
<Label
x:Name="name"
Text="{Binding Name}"
TextColor="Black"
VerticalOptions="StartAndExpand"
FontSize="14"
HorizontalOptions="Start"/>
</StackLayout>
</customcontrols:NoHighlightCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<Label Text="Selection required"
TextColor="Red"
Margin="0, 10, 0, 0"
IsVisible="{Binding ValidationRequired}"
VerticalOptions="StartAndExpand"
HorizontalOptions="FillAndExpand"
FontSize="14"/>
</StackLayout>
Here's my code behind:
private SoapNoteControlsViewModel viewModel;
public SelectListTemplate()
{
InitializeComponent();
}
protected override void OnDisappearing()
{
base.OnDisappearing();
}
protected override void OnAppearing()
{
base.OnAppearing();
LabelName.Text = viewModel.Label;
MultiselectList.ItemsSource = viewModel.CheckboxItems;
MultiselectList.SelectedItem = viewModel.SelectedItem;
//how would i set the BindingMode here? Doing .SetBinding doesn't seem to do it.
}
protected override void OnBindingContextChanged()
{
try
{
base.OnBindingContextChanged();
if(BindingContext == null)
{
return;
}
viewModel = BindingContext as SoapNoteControlsViewModel;
} catch (Exception e)
{
Console.WriteLine(e);
}
}
}
I tried doing .SetBinding, but it keeps saying that BindingMode is a type (given that it is an enum). Looking at some of the examples on MSDN haven't really helped

Answer 1

You would do it like this:
MultiselectList.SetBinding(ListView.ItemsSourceProperty, nameof(viewModels.CheckboxItems), BindingMode.TwoWay);
The first parameter is the property that you want to bind to - e.g. the ItemsSource.
The second parameter is the name of the property to look for - e.g. your viewModel's CheckBoxItems. This collection will be bound/populated in the list.
The last parameter is what you would want to achieve - the BindingMode. You are correct in saying that it is an enum, so here we can set it to BindingMode.TwoWay.
For reference: BindingMode's Remarks page.