SelectionChanged-Behavior-in-the-.NET-MAUI-ComboBox

The sample demonstrates how to manage the SelectionChanged behaviors in the .NET MAUI ComboBox control.

Getting Started with .NET MAUI ComboBox (SfComboBox)

Adding a .NET MAUI ComboBox reference

Syncfusion .NET MAUI controls are available in Nuget.org. To add .NET MAUI ComboBox to your project, open the NuGet package manager in Visual Studio, search for Syncfusion.Maui.Inputs and then install it.

Create a Simple .NET MAUI ComboBox

The .NET MAUI ComboBox control is configured entirely in C# code or by using XAML markup. The following steps explain how to create a .NET MAUI ComboBox (SfComboBox) and configure its elements:

Adding the .NET MAUI ComboBox control

Step 1: Add the NuGet to the project as discussed in the above reference section.

Step 2: Add the namespace as shown in the following code sample:

[XAML]

xmlns:inputs="clr-namespace:Syncfusion.Maui.Inputs;assembly=Syncfusion.Maui.Inputs"

Step 3: Set the control to content in ContentPage.

[XAML]

<ContentPage.Content>    
    <inputs:SfComboBox x:Name="comboBox" />
</ContentPage.Content>

Add a SelectionChanged Behavior to the .NET MAUI SfComboBox

[XAML]

  <ContentPage.BindingContext>
   <local:EmployeeViewModel/>
</ContentPage.BindingContext>

<StackLayout Padding="50,100,50,0">
   <inputs:SfComboBox x:Name="comboBox"
                      WidthRequest="200"
                      IsEditable="True"
                      SelectedIndex="2"
                      DisplayMemberPath="Name" 
                      ItemsSource="{Binding EmployeeCollection}"
                      MaxDropDownHeight = "180">
       <inputs:SfComboBox.Behaviors>
           <local:SelectionChangedBehavior/>
       </inputs:SfComboBox.Behaviors>
   </inputs:SfComboBox>
</StackLayout>

SelectionChanged Behavior

[C#]

 ppublic class SelectionChangedBehavior : Behavior<SfComboBox>
{
   public Command Display { get; private set; }
   EmployeeViewModel employeeViewModel;
   protected override void OnAttachedTo(SfComboBox bindable)
   {
       bindable.SelectionChanged += Bindable_SelectionChanged;
       base.OnAttachedTo(bindable);
   }
   protected override void OnDetachingFrom(SfComboBox bindable)
   {
       bindable.SelectionChanged -= Bindable_SelectionChanged;
       base.OnDetachingFrom(bindable);
   }

   async void Bindable_SelectionChanged(object sender, Syncfusion.Maui.Inputs.SelectionChangedEventArgs e)
   {
       employeeViewModel = new EmployeeViewModel();
       var selectedValue = e.CurrentSelection;
       var lastItem = selectedValue.Last();
       employeeViewModel.SelectedId = new List<string>();
       foreach (var item in selectedValue)
       {
           var selectedId = (item as Employee).Id;
           if (item == lastItem)
           {
               employeeViewModel.SelectedId.Add(selectedId);
               Application.Current.MainPage.DisplayAlert("Selected Id", "The last selected ID is " + selectedId, "Ok");
           }
           else
           {
               employeeViewModel.SelectedId.Add(selectedId);
           }
       }
   }
}

How to run this application?

To run this application, you need to first clone the How-to-bind-an-Enum-to-the-ItemsSource-property-of-.NET-MAUI-SfComboBox repository and then open it in Visual Studio 2022. Now, simply build and run your project to view the output.

Troubleshooting

Path too long exception

If you are facing path too long exception when building this example project, close Visual Studio and rename the repository to short and build the project.

License

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