WPF ComboBox databinding xaml vs. code

Question

I am by no means an expert on WPF so this is probably very simple. I'm trying to bind a List to a combobox. It works in code, it doesn't work in xaml. If I remove the ItemsSource from the constructor, it doesn't work, which is how I know. I thought I had the equivalent in xaml, but apparently it's not.

xaml:

    <ComboBox Height="23"
              HorizontalAlignment="Left"
              Margin="146,76,0,0"
              Name="comboBox1"
              VerticalAlignment="Top"
              Width="120"
              ItemsSource="{Binding AvailableActions}"
              DisplayMemberPath="Name"
              SelectedValuePath="Name"
              SelectedValue="Replace" />

constructor:

    public MainWindow()
    {
        _availableActions = new List<IMapperAction>
                       {
                           new ReplaceAction(),
                           new CollapseAction(),
                           new NewBasedOnAction()
                       };

        InitializeComponent();
        Loaded += OnWindowLoaded;

        comboBox1.ItemsSource = AvailableActions;
    }

score 2 · Accepted Answer · answered May 20 '11 at 07:15

2

Well, you need to set the DataContext of the main window:

public MainWindow()
{
    _availableActions = new List<IMapperAction>
                   {
                       new ReplaceAction(),
                       new CollapseAction(),
                       new NewBasedOnAction()
                   };

    InitializeComponent();
    DataContext = this;
    Loaded += OnWindowLoaded;
}

answered May 20 '11 at 07:15

ChrisWue

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Oh I see. Thanks! Why did it work in code? Because it was pushing the context to the xaml rather than doing it from xaml, which would mean needing a context in which to "talk" to? – George R May 20 '11 at 07:21
1

in works in code because you set the itemsource directly, without binding. – blindmeis May 20 '11 at 07:29

score 0 · Answer 2 · edited May 23 '17 at 12:12

0

As suggested here, you have to set the DataContext.

You can also read this link to know why and when which of the two should be used:

Why are DataContext and ItemsSource not redundant?

edited May 23 '17 at 12:12

Community

1
1

answered May 20 '11 at 07:23

Mamta D

6,310
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WPF ComboBox databinding xaml vs. code

2 Answers2