wpf binding to string

Question

I have a Movie class with a Dim _characters = New ObservableCollection(of String)
Characters is the associated property to get and set

How can i get characters to show up in the listBox using Binding?
So far i have the following, this isn't working as i don't know what to put instead of ToString.

<ListBox Name="cList" ItemsSource="{Binding Characters}">

 <ItemsControl >
   <ItemsControl.ItemTemplate >
    <DataTemplate >
     <TextBox Text="{Binding ToString}"/>  
    </DataTemplate> 
   </ItemsControl.ItemTemplate> 
 </ItemsControl>

 </ListBox> 

I want them to be editable, hence a textbox.

i tried to bind Characters to TextBox directly, even that didn't work.

Edit : in the code i have parentGrid1.DataContext = me.movies where
parent grid holds movies.

Solution 1

You cannot perform two-way binding to ObservableCollection<string>. In order to make the strings editable you have to create a class with a string get/set property as the following class Foo:

public class Foo
{
    string _text;

    public Foo(string text)
    {
        _text = text;
    }
    public string Text 
    {
        get { return _text; }
        set { _text = value; }
    }
}

Your Characters should then be of type ObservableCollection<Foo> and your XAML should be changed so that the textboxes are binding to Foo.Text:

<ListBox ItemsSource="{Binding Characters}" >
    <ListBox.ItemTemplate >
        <DataTemplate >
            <TextBox Text="{Binding Text}"/>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

Solution 2

For those who are experiencing the exception

... binding requires path or xpath ...

You can bind the object directly this way:

<Label Content="{Binding .}" />

Solution 3

Change your TextBox binding to the following. I think it should work:

<TextBox Text="{Binding}"/>

This loads the item itself instead of a property or method output. Since the item is a string it should bind to the strings value.

Solution 4

Just remove the ToString portion of the code.

Currently you are telling the program that you want to bind to an object called ToString

Solution 5

I take it that Characters is a public property. Debug and be sure that get is being called for Characters. If you have a the datacontext of the page/window to Movies then you need ItemsSource on the ListBox to be {Binding Path=Characters}

View more solutions

Comments

[Joachim Kerschbaumer]

Try just something like this : <TextBox Text="{Binding}"/> as the current context within the itemscontrol is a string. just bind to the current datacontext ({Binding}) without providing any further path.

[heyNow]

gives an error saying 2 way binding requires path or xpath

[Jakob Christensen]

@sitsOnRedChair: This is because you cannot perform two-way binding to ObservableCollection<string>. See my answer below: stackoverflow.com/questions/6943726/wpf-binding-to-string/…

[heyNow]

YES! i just did that & it worked finally. created a class Character with a Name property, bound the Name to the textBox, its working now.

[heyNow]

just out of curiosity why doesn't it work with strings? they are just like every other object

[Jakob Christensen]

It does not work with strings or any other object when you perform the binding directly to the object because the WPF binding cannot insert new objects into the ObservableCollection. It can only change properties on the objects already in the collection. If you use {Binding Text, Mode=OneWay} it will work but then of course you cannot change the strings.

[CodeWarrior]

Ahh I completely glossed over the fact that it was a textbox rather than a textblock. My apologies.