我的WPF列表视图不会绑定

Question

This may seem an odd question but I am stuck.

I am using ListViews in my wpf app that dynamically binds to list collections.

Apart from one. I just cannot see what is wrong/different.

This is my model:

public class WorkUnitCost
{
    public string ErrorMessage { get; set; }
    public int WorkUnitCostId { get; set; }
    public bool IsUploaded { get; set; }
    public string WorkUnitCostRef { get; set; }
    public string Description { get; set; }
    public double Cost { get; set; }
    public bool IncludesVAT { get; set; }
    public string CompanyRef { get; set; }
    public bool Active { get; set; }
    public bool Exists { get; set; }
    public string Caption
    {
        get { return Description + " £" + Cost; }
    }
}

This is my collection:

public List<WorkUnitCost> WorkUnitCost = new List<Model.WorkUnitCost>();

This is my code-behind:

lvWorkItems.ItemsSource = WorkUnitCost;

This is my markup:

     <ListView x:Name="lvWorkItems">           
        <ListView.View>
            <GridView>
                <GridViewColumn Header="Description" Width="190" DisplayMemberBinding="{Binding Description}"  />
                <GridViewColumn Header="IsVat" Width="50" DisplayMemberBinding="{Binding IncludesVAT}" />
                <GridViewColumn Header="Cost" Width="75" DisplayMemberBinding="{Binding Cost}" />
            </GridView>
        </ListView.View>
    </ListView>

By setting a break-point I know there are 2 items with populated fields. Yet, nothing is visually displayed?

Answer 1

If you are adding items to your colleciton after setting it as ItemsSource , your UI won't get notified about changes.

You will have to use some collection implementing INotifyCollectionChanged instead. ObservableCollection<T> is most common choice.

Answer 2

I think you need to implement The INotifyCollectionChanged to your model and instead of List try to use ObservableCollection<WorkUnitCost> to enable your view synchronize with your model data. Actually It will be better if you use MVVM to ensure the best practices for WPF , you will find at this link a good explanation of how to use ObservableCollection and INotifyPropertyChanged with MVVM design pattern