---
lang: ja-jp
breaks: true
---
# WinUI 3 コンボボックスにEnum型をバインドして使用する 2022-07-29

## MainWindow.xaml

<Window
	x:Class="App25.MainWindow"
	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
	xmlns:local="using:App25"
	xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
	mc:Ignorable="d"
	xmlns:viewModels="clr-namespace:App25.viewModels"
	>
    <Grid>
        <StackPanel >
            <ComboBox 
                Header="Nuget Organizations" 
                PlaceholderText="Nuget Organizations" 
                Width="400" 
                ItemsSource="{x:Bind ViewModel.Organizations, Mode=OneTime}"
                SelectedItem="{x:Bind ViewModel.Organization, Mode=TwoWay}"
                />
        </StackPanel>
    </Grid>

</Window>

:::info
選択された項目をバインドするプロパティは、`SelectedItem`を使用する。
:::

## MainWindow.xaml.cs

namespace App25;

/// <summary>
/// An empty window that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainWindow : Window
{
    private MainWindowViewModel ViewModel { get; init; }

    public MainWindow()
    {
        this.InitializeComponent();

        ViewModel = new MainWindowViewModel();
    }
}

## MainWindowViewModel.cs

namespace App25.viewModels;

internal sealed class MainWindowViewModel:
    INotifyPropertyChanged
{
    public enum Organization
    {
        orgs,
        user
    }

    public IReadOnlyList<Organization> Organizations
    {
        get
        {
            return Enum.GetValues<Organization>();
        }
    }

    private Organization? m_organization;
    public GithubPackagesAPI.Organization? Organization { get { return this.m_organization; } set { if (value == this.m_organization) { return; } this.m_organization = value; OnPropertyChanged(nameof(Organization)); } }
    public event PropertyChangedEventHandler PropertyChanged;
    public event PropertyChangedEventHandler PropertyChanged_Organization;
    private void OnPropertyChanged([System.Runtime.CompilerServices.CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        switch (propertyName)
        {
            case nameof(Organization):
                PropertyChanged_Organization?.Invoke(this, new PropertyChangedEventArgs(propertyName));
                break;
        }
    }
}

:::warning
コンボボックスの`ItemsSource`にバインドするリストは、`Enum.GetValues<Organization>()`か、`FastEnumUtility.FastEnum.GetValues<GithubPackagesAPI.Organization>().ToArray()`でも可能。

`FastEnumUtility.FastEnum.GetValues<GithubPackagesAPI.Organization>()`では、`SelectedItem`が正常にバインドできなかった。

:::

###### tags: `WinUI 3` `コンボボックス` `Combobox`