How to call function with parameters from command - mvvm

Question

I'm trying to call command which is bindable in tapgesture...
Why TabTappedCommand doesn't do nothing...
IrrigNetPage.xaml
<StackLayout BackgroundColor="{Binding SelectedTabColor}"
x:Name="StackService">
<StackLayout.GestureRecognizers>
<TapGestureRecognizer Command="{Binding TabTappedCommand}" CommandParameter="service"/>
</StackLayout.GestureRecognizers>
<Image Source="{Binding ServiceTabIcon}"
HorizontalOptions="Start"
VerticalOptions="Center"
WidthRequest="16"
HeightRequest="16"
Aspect="AspectFit"
x:Name="ServiceIcon"/>
<Label Text="{i18n:Translate Service}"
VerticalOptions="FillAndExpand"
HorizontalOptions="FillAndExpand"
VerticalTextAlignment="Center"
HorizontalTextAlignment="Start"
TextColor="{Binding SelectedTabTextColor}"
x:Name="ServiceText"/>
</StackLayout>
IrrigNetViewModel.cs
public string ServiceTabIcon { get; set; } = "services_sel.png";
public string LocationTabIcon { get; set; } = "location.png";
public string MapTabIcon { get; set; } = "location.png";
public string ListHederIcon { get; set; } = "service_irrig.png";
public ICommand TabTappedCommand { get; }
public IrrigNetViewModel()
{
TabTappedCommand = new Command((tabName) => OnTapClicked(tabName.ToString()));
}
private void OnTapClicked(string tabName)
{
string serviceBlackIcon = "services.png";
string locationWhiteIcon = "location_sel.png";
string mapWhiteIcon = "location_sel.png";
if (tabName == "service")
{
ServiceTabIcon = "services_sel.png";
LocationTabIcon = "location.png";
MapTabIcon = "location.png";
}
else if (tabName == "location")
{
ServiceTabIcon = "services.png";
LocationTabIcon = "location_sel.png";
MapTabIcon = "location.png";
}
else
{
ServiceTabIcon = "services.png";
LocationTabIcon = "location.png";
MapTabIcon = "location_sel.png";
}
}
So, point is to change icons of selected stackLayout (and back to default icons when it's unselected) but for some reason TabTappedCommand doesn't work... What I'm missing...?

Answer 1

Solution:
Refer to the following code
public class IrrigNetViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private string serviceTabIcon = "services.png";
public string ServiceTabIcon
{
get { return serviceTabIcon; }
set
{
serviceTabIcon = value;
PropertyChanged(this, new PropertyChangedEventArgs("ServiceTabIcon"));
}
}
private string locationTabIcon = "services.png";
public string LocationTabIcon
{
get { return locationTabIcon; }
set
{
locationTabIcon = value;
PropertyChanged(this, new PropertyChangedEventArgs("LocationTabIcon"));
}
}
private string mapTabIcon = "location.png";
public string MapTabIcon
{
get { return mapTabIcon; }
set
{
mapTabIcon = value;
PropertyChanged(this, new PropertyChangedEventArgs("MapTabIcon"));
}
}
private string listHederIcon = "services.png";
public string ListHederIcon
{
get { return listHederIcon; }
set
{
listHederIcon = value;
PropertyChanged(this, new PropertyChangedEventArgs("ListHederIcon"));
}
}
public ICommand TabTappedCommand { get; }
public IrrigNetViewModel()
{
TabTappedCommand = new Command((tabName) => OnTapClicked(tabName.ToString()));
}
private void OnTapClicked(string tabName)
{
if (tabName == "service")
{
ServiceTabIcon = "location.png";
LocationTabIcon = "location.png";
MapTabIcon = "location.png";
}
else if (tabName == "location")
{
ServiceTabIcon = "services.png";
LocationTabIcon = "location_sel.png";
MapTabIcon = "location.png";
}
else
{
ServiceTabIcon = "services.png";
LocationTabIcon = "location.png";
MapTabIcon = "location_sel.png";
}
}
}

Answer 2

You are missing the Generic type for the Command that is required to pass a parameter.
public ICommand TabTappedCommand<string> { get; }
public IrrigNetViewModel()
{
TabTappedCommand = new Command<string>(OnTapClicked);
}