CODEWITHSUNDEEP
c#wpfxamlobservablecollection
user1135183
user1135183

Reputation:

Bind Observable collection

How would I go about binding this in XAML?

I am looking to use an observable collection to populate a ListView ever time a method is called which will be through a drop event on another control. The collection is getting added too but the ListView won't populate.

I haven't been using WPF long so any insight would be great. 

namespaceA 
{
    public class SomeClassA
    {
        public string FirstName { get; set; }
    }

    public class SomeClassB
    {
        public void MethodA()
        {
            ObservableCollection<SomeClassA> Name_Col = new ObservableCollection<SomeClassA>();
            Name_col.Add(new SomeClassA { FirstName = "SomeValue" });
        }
    }
}

XAML:

 <ObjectDataProvider
    x:Key="Viewmodel"
    ObjectType="{x:Type Local:NamespaceA}"/>

 <ListView DataContext="{StaticResource Viewmodel}"
    Height="396" 
    HorizontalAlignment="Left" 
    Margin="766,67,0,0" 
    Name="listView1" 
    VerticalAlignment="Top" 
    Width="260" 
    ItemsSource="{Binding Name_col}" />

Upvotes: 0

Views: 1562

Answers (3)

Rachel
Rachel

Reputation: 132648

There are quite a few things wrong with your code

First off, your DataContext is pointing to a namespace, not an object. Change that to be an instance of an object.

<ObjectDataProvider x:Key="Viewmodel" ObjectType="{x:Type local:SomeClassB}"/>

Or 

<local:SomeClassB x:Key="Viewmodel" />

Second, your ObservableCollection is not a public property, so your View cannot see nor access it.

public class SomeClassB
{
    public ObservableCollection<SomeClassA> Name_Col { get; set; }

    public void MethodA()
    {
        Name_Col = new ObservableCollection<SomeClassA>();
        Name_col.Add(new SomeClassA { FirstName = "SomeValue" });
    }
}

And last of all, WPF bindings are case-sensitive so you need to fix the ItemsSource binding to use the correct case

<ListView ... 
    ItemsSource="{Binding Name_Col}" />

Upvotes: 1

Nuffin
Nuffin

Reputation: 3972

The only things you can access in bindings are public (internal doesn't work) properties and indexers of public classes.

And no matter how, variables declared inside a method will never be accessible from anywhere outside the said method. It's a common mistake people who used to work with scripting languages often make. To access something outside a method (or inside of another), that must be declared outside of the method.

One useful hint: Visual Studio's Output window is a very useful tool for tracking binding errors.

On a side note: Bindings are case sensitive. Even if your code followed the rules mentioned above, WPF would still not find the binding source, as your binding path is Name_col, but the property's name is Name_Col.

Upvotes: 4

Justin Fyles
Justin Fyles

Reputation: 160

Assuming this code is pasted, your binding is looking at a nonexistent property. Try capitalizing the 'c' in your binding. Name_col -> Name_Col

Upvotes: 0

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