how to have 2 data binding fields in one Xamarin forms label?

Question

I'm working on an app in xamarin froms that gets data from a service. What I'm trying to do is make the first name and last name fields display in the same label however it currently displays first name then it returns a line and then shows the last name. This is my XAML code:

  <?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="ReadyMo.ContactInfo">
              <ListView ItemsSource="{Binding .}" HasUnevenRows="true">
               <ListView.ItemTemplate>
      <DataTemplate>
        <ViewCell>
          <Frame Padding="0,0,0,8" BackgroundColor="#d2d5d7">
            <Frame.Content>
              <Frame Padding="25,25,25,25"   OutlineColor="Gray" BackgroundColor="White">
                <Frame.Content>
                  <StackLayout Padding="20,0,0,0"  HorizontalOptions="CenterAndExpand" >
                    <Label x:Name="FirstName" Text="{Binding First_Name}">
                        </Label>
                        <Label x:Name ="LastName" Text="{Binding Last_Name}">
                        </Label>
                        <Label x:Name="County" Text="{Binding name}">
                        </Label>
                        <Label x:Name ="Adress" Text="{Binding Address1}">
                        </Label>
                          <Label x:Name ="City" Text="{Binding Address2}">
                        </Label>
                        <Label x:Name="Number"  Text="{Binding BusinessPhone}" >
                        </Label>   
                  </StackLayout>
                </Frame.Content>
              </Frame>
            </Frame.Content>
          </Frame>
        </ViewCell>
      </DataTemplate>
    </ListView.ItemTemplate>
  </ListView>
</ContentPage>

EDIT Here's My codebehind:

using Newtonsoft.Json;
using ReadyMo.Data;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Net.Http;
using System.Threading.Tasks;

using Xamarin.Forms;

namespace ReadyMo
{

    public partial class ContactInfo : ContentPage
    {


        private County item;

        public static async Task<string> GetContactString(string contactid)
        {
            HttpClient client = new HttpClient();
            var url = $"URL";
            var response = await client.GetAsync(url);
            if (response.IsSuccessStatusCode)
            {
                var responsetext = await response.Content.ReadAsStringAsync();
                return responsetext;
            }
            throw new Exception(response.ReasonPhrase);
        }

        public ContactInfo()
        {
            InitializeComponent();
            ContactInfoList = new ObservableCollection<ContactInfoModel>();
        }

        ObservableCollection<ContactInfoModel> ContactInfoList;

        public ContactInfo(County item) : this()
        {
            this.item = item;
            this.BindingContext = ContactInfoList;
        }

        protected override async void OnAppearing()
        {
            if (item == null)
                return;
            var contact = await GetContactString(item.id);
            var models = JsonConvert.DeserializeObject<List<ContactInfoModel>>(contact);
            foreach (var model in models)
                ContactInfoList.Add(model);



        }

    }
}

any help would be amazing!

Answer 1

*Update: With the release of Xamarin Forms 4.7, you can now use Multi-Bindings instead of creating a getter property. Using the first and last name example, you would do something like this:

<StackLayout Padding="20,0,0,0"  HorizontalOptions="CenterAndExpand" >
    <Label x:Name="FirstName">
        <Label.Text>
            <MultiBinding StringFormat="{}{0} {1}">
                <Binding Path="FirstName" />
                <Binding Path="LastName" />
            </MultiBinding>
        </Label.Text>
    </Label>
    .........
</StackLayout>

*Pre-Xamarin Forms 4.7 What I do in this situation is to put an extra property on the model that combines the two properties.

public class ContactInfo {
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string FirstLastName { get { return FirstName + " " + LastName; }}
    //Or use C# 6 goodness
    //public string FirstLastName => FirstName + " " + LastName;
}

Now in your ViewModel, if first or last name changes, you would need to do something like this to update the FirstLastName property:

private string _firstLastName;
public string FirstLastName {
    get { return _firstLastName; }
    set {
        if(_firstLastName != value) {
            _firstLastName = value;
            SetPropertyChanged();
        }
    }
}

private string _firstName;
public string FirstName {
    get { return _firstName; }
    set {
        if(_firstName != value) {
            _firstName = value;
            SetPropertyChanged();
            SetPropertyChanged("FirstLastName"); //Also send alert that FirstLastName changed
        }
    }
}

Then do the same for you LastName property.

Edit: Your XAML would then look like:

<StackLayout Padding="20,0,0,0"  HorizontalOptions="CenterAndExpand" >
    <Label x:Name="FirstName" Text="{Binding FirstLastName}"/>
    .....
</StackLayout>

Edit2: So since you are probably not ever changing the First or Last Name property while showing the UI, you just need to add the property to your model, like I show in the ContactInfo code above, and then change your label, like I show in the edit above and you will be good to go.

Answer 2

As Ed Phuket said it is working but :
You need to add Mode=OneWay if you want it to update with OnPropertyChanged event to the span because it has OneTime Binding mode as default

Answer 3

While the team at Xamarin Forms are still figuring out Binding with the Span element, you can just change the formatting of the Labels to get this working:

    <StackLayout Orientation="Horizontal" Padding="0" Margin="0" Spacing="0">
        <Label Text="{Binding First_Name}" Margin="0" />
        <Label Text=" " Margin="0" />
        <Label Text="{Binding Last_Name}" Margin="0" />
    </StackLayout>