CODEWITHSUNDEEP
c#wpfxamlcomboboxdatatemplate
PatrickV
PatrickV

Reputation: 2135

ComboBox Item Selection Works With Keyboard But Not Mouse

I have a combo box that is not working as I expect at runtime. I can use the mouse to expand the drop-down window, but clicking an item does not seem to select it. The dropdown goes away, but the selection is not changed. The same control seems to work as expected using the keyboard. Arrow up/down changes the selection. I can use the arrow keys to choose and enter to select to change the value as well.

How do I get clicking to select an item?

  <DataTemplate DataType="{x:Type myType}">
    <Border ...>
      <Grid x:Name="upperLayout">
        <Grid x:Name="lowerLayout">
          <ComboBox x:Name="combo"
            Grid.Column="2"
            ItemsSource="{Binding Things}"
            SelectedItem="{Binding SelectedThing}"
            >
            <ComboBox.ItemTemplate>
              <DataTemplate>
                <TextBlock Text="{Binding Name}" />
              </DataTemplate>
            </ComboBox.ItemTemplate>
          </ComboBox>
        </Grid>
      </Grid>
    </Border>
  </DataTemplate>

Upvotes: 2

Views: 2764

Answers (2)

aybe
aybe

Reputation: 16652

I can't really tell what's wrong from your code however, I'd strongly suggest you to use Snoop to debug your controls (http://snoopwpf.codeplex.com/)

By holding Ctrl+Shift and pointing the mouse where you ComboBox is supposed to grab the input you would instantly find out who is having the focus instead of your combo box.

enter image description here

You can even change the value of a property, really your best friend for debugging your templates !

EDIT

I'm afraid but the code you've posted works for me:

<Window x:Class="WpfApplication6.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:wpfApplication6="clr-namespace:WpfApplication6"
        Title="MainWindow"
        Width="525"
        Height="350">
    <Window.Resources>
        <DataTemplate x:Key="myTemplate" DataType="{x:Type wpfApplication6:MyType}">
            <Border>
                <Grid x:Name="upperLayout">
                    <Grid x:Name="lowerLayout">
                        <ComboBox x:Name="combo"
                                  Grid.Column="0"
                                  ItemsSource="{Binding Path=Things}"
                                  SelectedItem="{Binding Path=SelectedThing}">
                            <ComboBox.ItemTemplate>
                                <DataTemplate DataType="{x:Type wpfApplication6:MyThing}">
                                    <TextBlock Text="{Binding Name}" />
                                </DataTemplate>
                            </ComboBox.ItemTemplate>
                        </ComboBox>
                    </Grid>
                </Grid>
            </Border>
        </DataTemplate>
    </Window.Resources>
    <Grid x:Name="grid">
        <ContentControl x:Name="content" ContentTemplate="{StaticResource myTemplate}" Margin="58,79,71,40" />
    </Grid>
</Window>

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        Loaded += MainWindow_Loaded;
    }

    private void MainWindow_Loaded(object sender, RoutedEventArgs e)
    {
        MyType type = new MyType()
            {
                Things = new List<MyThing>() {new MyThing() {Name = "aaa"}, new MyThing() {Name = "bbb"}}
            };
        content.Content = type;
    }
}

public class MyType
{
    public MyThing SelectedThing { get; set; }
    public List<MyThing> Things { get; set; }
}

public class MyThing
{
    public string Name { get; set; }
}

Maybe something else is screwing it such as a style with no key or whatever, post more of your code you're having a problem with.

Upvotes: 1

PatrickV
PatrickV

Reputation: 2135

Root cause was that another developer had implemented some code that changed the focus on the preview mouse down event. This code was updated to have the desired behavior without modifying focus and the combo box now works as expected. The information needed to diagnose was not in the original question (can't publish it all...).

Upvotes: 0

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