CODEWITHSUNDEEP
wpfmvvm
Jinsu Lim
Jinsu Lim

Reputation: 11

WPF MVVM I want to bring data from another Window ViewModel and use it

I'm creating a customer care program using WPF MVVM pattern I created a registration window and a customer information window I want to bring the value of the data grid of the customer information window to the text box of the creation window

This is information ViewModel

public class MainViewModel : ObservableObject
{
   private MemberInfo selectedCustomer = new MemberInfo();
      
   public MemberInfo SelectedCustomer
  {
      get => selectedCustomer;
      set
      {   
          SetProperty(ref selectedCustomer, value);

          RegisterViewModel RV = new RegisterViewModel();

          if (value != null)
          {
              RV.Name = selectedCustomer.Name;
           }
        }
    }
 }

This is Creat ViewModel

 public class RegisterViewModel : ObservableObject
 {
     private string name = "";
     public string Name
     {
         get => this.name;
         set => SetProperty(ref this.name, value);
      }
  }

If I use it like this, the value goes over only set, and there is no value to execute the get

Upvotes: 1

Views: 115

Answers (1)

Kostas K.
Kostas K.

Reputation: 8518

If I use it like this, the value goes over only set, and there is no value to execute the get

Not entirely sure I understood this correctly, but you could pass a MemberInfo object to the constructor of the RegisterViewModel and expose it to the view via a read-only property.

So, the RegisterViewModel becomes:

public class RegisterViewModel : ObservableObject
{
    public RegisterViewModel(MemberInfo member)
    {
         Member = member;
    }

    public MemberInfo Member { get; }
 }

Thus in the MainViewModel:

public MemberInfo SelectedCustomer
{
    get => selectedCustomer;
    set
    {   
         SetProperty(ref selectedCustomer, value);
         RegisterViewModel RV = new RegisterViewModel(selectedCustomer);
     }
}

The view then binds to:

Text = "{Binding Path=Member.Name, Mode=TwoWay}"

Edit

Since the RegisterViewModel is expecting a MemberInfo object, you cannot register it and simply call the GetService<T> method.

What I usually do in this case, I make use of the ActivatorUtilities.CreateInstance which is part of the Microsoft.Extensions.DependencyInjection.Abstractions package.

Through an extension method:

public static T Create<T>(this IServiceProvider provider, params object[] args) where T : class
{
    return ActivatorUtilities.CreateInstance<T>(provider, args);
}

Which can then be called:

this.DataContext = App.Current.Services.Create<RegisterViewModel>(member);

This way, if the RegisterViewModel is expecting additional registered services through the constructor, those will be resolved by the container.

Upvotes: 1

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