Using MVVM Pattern Binding WPF Grid to a WCF Service - wcf

Question

I am trying to bind the data returned from WCF service to a grid in WPF using MVVM. The same works when i use the logic of WCF service in view model.
Code Behind:
this.DataContext = new SampleViewModel();
View/XAML:
<Window x:Class="Sample.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<DataGrid ItemsSource="{Binding Students}" AutoGenerateColumns="False" >
<DataGrid.Columns>
<DataGridTextColumn Header="ID" Binding="{Binding ID}" />
<DataGridTextColumn Header="Name" Binding="{Binding Name}" />
<DataGridTextColumn Header="Address" Binding="{Binding Address}" />
</DataGrid.Columns>
</DataGrid>
</Grid>
</Window>
View Model:
public List<Student> Students {
get {
var service = new StudentServiceClient();
var students = new List<Student>(service.GetStudents());
return students;
}
}
IStudentService:
[ServiceContract]
public interface IStudentService {
[OperationContract]
IEnumerable<Student> GetStudents();
}
[DataContract]
public class Student {
public string Name { get; set; }
public int ID { get; set; }
public string Address { get; set; }
}
StudentService.svc:
public class StudentService : IStudentService {
public IEnumerable<Student> GetStudents() {
var students = new List<Student>();
for (int i = 0; i < 3; i++) {
students.Add(new Student {
Name = "Name" + i,
ID = i,
Address = "Address" + 1
});
}
return students;
}
}
When i run the app, i dont see ant records in the grid..

Answer 1

public List<Student> Students {
get {
var service = new StudentServiceClient();
var students = new List<Student>(service.GetStudents());
return students;
}
}
Every time the Students property is used/read this code will connect to the server and retrieve the students. That will be too slow.
Load the Students in the constructor of the ViewModel (or in a separate method/command) and return this collection from the getter.
The reasons why your solution doesn't work can be:
List doesn't notify the View of changes of the collection; use ObservableCollection instead.
When the Students property changes (var students = new List<Student>(service.GetStudents());) there is no signal to the View that the property has changed; Implement INotifyPropertyChanged on the ViewModel.
Make sure the Service returns data.

Answer 2

Are there any binding errors? Or maybe there is a serviceside problem, and the service returns no entries. Did you debug / breakpoint the property's getter and check the result?