Rank 1
Binding multiple selected to RadComboBox after getting the data not work
xaml code <telerik:RadComboBox ItemsSource="{Binding Skills}"
SelectedItem="{Binding SelectedSkillItems,Mode=TwoWay}"
Placeholder="Select Skills"
MaximumWidthRequest="{OnPlatform WinUI='300', MacCatalyst='300'}"
SelectionMode="Multiple"
IsDropDownClosedOnSelection="False"/>
public ObservableCollection<string> Skills { get; set; }
public ObservableCollection<string> SelectedSkillItems
{
get => selectedSkillItems;
set =>UpdateValue(ref selectedSkillItems, value);
}
Skills = new ObservableCollection<string>()
{
".NET MAUI",
"Xamarin",
"Blazor",
"WPF",
"WinUI",
"Fiddler",
"Sitefinity",
"Test Studio",
"Open Edge",
"Kinvey",
"DataRPM",
"Corticon"
};
SelectedSkillItems =new ObservableCollection<string>(new List<string>() { "Xamarin", "WPF" });
1 Answer, 1 is accepted
SelectedItems collection of RadComboBox is read-only, so you cannot bind with TwoWay binding to it, you can only get the collection (OneWay binding) and add/remove items.
Here is an example for SelectedItems collection:
public class ViewModel : NotifyPropertyChangedBase
{
private int selectedIndex;
private City selectedItem;
private ObservableCollection<object> selectedItems;
public ViewModel()
{
this.Items = new ObservableCollection<City>
{
new City { Name = "Tokyo", Population = 13929286 },
new City { Name = "New York", Population = 8623000 },
new City { Name = "London", Population = 8908081 },
new City { Name = "Madrid", Population = 3223334 },
new City { Name = "Los Angeles", Population = 4000000},
new City { Name = "Paris", Population = 2141000 },
new City { Name = "Beijing", Population = 21540000 },
new City { Name = "Singapore", Population = 5612000 },
new City { Name = "New Delhi", Population = 18980000 },
new City { Name = "Bangkok", Population = 8305218 },
new City { Name = "Berlin", Population = 3748000 },
};
this.SelectedIndex = 1;
this.SelectedItem = this.Items[2];
}
public ObservableCollection<City> Items { get; set; }
public ObservableCollection<object> SelectedItems
{
get
{
return this.selectedItems;
}
set
{
if (this.selectedItems != value)
{
this.selectedItems = value;
this.selectedItems.Add(this.Items[0]);
this.selectedItems.Add(this.Items[1]);
this.OnPropertyChanged();
}
}
}
public int SelectedIndex
{
get
{
return this.selectedIndex;
}
set
{
if (this.selectedIndex != value)
{
this.selectedIndex = value;
OnPropertyChanged();
}
}
}
public City SelectedItem
{
get
{
return this.selectedItem;
}
set
{
if (this.selectedItem != value)
{
this.selectedItem = value;
OnPropertyChanged();
}
}
}
}
<telerik:RadComboBox ItemsSource="{Binding Items}"
SelectionMode="Multiple"
DisplayMemberPath="Name"
SelectedItems="{Binding SelectedItems}">
<telerik:RadComboBox.BindingContext>
<local:ViewModel/>
</telerik:RadComboBox.BindingContext>
</telerik:RadComboBox>The Example in the documentation will be updated.
For multiple selection mode use the ComboBox.SelectedItems collection. Example is provided here: https://github.com/telerik/maui-samples/blob/5e0097e9c3410a14fb254d13e2d1c66ad33ceebf/Samples/SdkBrowser/Examples/ComboBoxControl/FeaturesCategory/SelectionExample/Selection.xaml#L39
The SelectedSkillItems property form the ViewModel must be bound to the Combobox.SelectedItems property, not to the SelectedItem.