CODEWITHSUNDEEP
c#wpfcombobox
CM99
CM99

Reputation: 313

Combobox Only show some comboxitems

Ive set up a ComboBox with about 20 ComboBox items in it. I wanted to be able to limit the number the user can see when they click a check box e.g

if (checkbox1.ischecked)    
{
    combobox1.items = item 1, item 2 // correct code here    
}

been searching the web and MSDN etc and i am not even sure if its possible any pointers in the right direction would be appreciated

Upvotes: 1

Views: 1788

Answers (2)

AlSki
AlSki

Reputation: 6961

If you don't want to change the collection, you can simply tweak the visibility, so given this xaml

    <ComboBox x:Name="itemsBox">
        <ComboBox.Items>
            <ComboBoxItem x:Name="itemRed" Content="Red"/>
            <ComboBoxItem Content="White"/>
            <ComboBoxItem x:Name="itemBlue" Content="Blue"/>
        </ComboBox.Items>
    </ComboBox>
    <CheckBox x:Name="checkBox" Click="checkBox_Click"/>

You just need,

private void checkBox_Click(object sender, RoutedEventArgs e)
{
    itemBlue.Visibility = checkBox.IsChecked.Value ? Visibility.Collapsed : Visibility.Visible;
    itemRed.Visibility = checkBox.IsChecked.Value ? Visibility.Collapsed : Visibility.Visible;
}

However Sheridan's answer will be far more flexible in the long term as filtering the collections is a far better way to go. If you are trying to do anything other than expose/hide a fixed set of items (note mine above are named explicitly) you really should move to ItemsSource

i.e. If you start doing this,

private void checkBox_Click(object sender, RoutedEventArgs e)
{
    foreach(var x in new ComboBoxItem[] { ItemBlue, ItemRed /*, etc*/ })
    {
        x.Visibility = checkBox.IsChecked.Value ? Visibility.Collapsed : Visibility.Visible;
     }
 }

Then refactor it to an ItemsSource

Upvotes: 1

Sheridan
Sheridan

Reputation: 69959

Basically, you will have to decide which items will be added to suit you, but in this example, I'm just picking the first 5 items:

if (checkBox1.IsChecked)
{
    ObservableCollection<YourItemType> filteredCollection = originalItemsSource.Take(5);
    comboBox1.ItemsSource = filteredCollection;
}
else comboBox1.ItemsSource = originalItemsSource;

Note also that I am assuming that you have set the ComboBox.ItemsSource to a collection (the full collection) named originalItemsSource, which remains full and unaltered.

Upvotes: 4

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