CODEWITHSUNDEEP
c#wpfdata-bindingmvvmviewmodel
Pallas
Pallas

Reputation: 1579

Problems setting up databinding with WPF and MVVM

I have an application that uses MVVM. I'm trying to set up the databinding for my ComboBox by connecting it to the Properties in my ViewModel. When I run the application I get this error message:

Message='Provide value on 'System.Windows.Data.Binding' threw an exception.' Line number '11' and line position '176'.

The problem occurs with this line of XAML:

<ComboBox x:Name="schoolComboBox" HorizontalAlignment="Left" Margin="25,80,0,0" VerticalAlignment="Top" Width="250" FontSize="16" ItemsSource="{Binding LocationList}" SelectedItem="{Binding Source=LocationPicked}" />

Below is the ViewModel that I'm trying to use.

using QMAC.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Windows;

namespace QMAC.ViewModels
{
  class MainViewModel : ViewModelBase
  {
    Address address;
    Location location;
    private string _locationPicked;

    public MainViewModel()
    {
        address = new Address();
        location = new Location();
    }

    public List<string> LocationList
    {
        get { return location.site; }
        set
        {
            OnPropertyChanged("LocationList");
        }
    }

    public string LocationPicked
    {
        get { return _locationPicked; }
        set
        {
            _locationPicked = value;
            MessageBox.Show(_locationPicked);
            OnPropertyChanged("LocationPicked");
        }
    }
  }
}

Am I setting up the property incorrectly for it to work with the databinding?

Upvotes: 1

Views: 2635

Answers (1)

evanb
evanb

Reputation: 3111

You are not binding the SelectedItem correctly. You need to set the Path on the binding and not the Source. I'm assuming that you have set the datacontext to the MainViewModel. Since the LocationPicked property is in the MainViewModel you don't need to set the Binding.Source. Change your binding to set the Path on the SelectedItem using {Binding LocationPicked.

Upvotes: 3

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