C# irstOrDefault（）。显示名称：SelectedCountry SelectedCountry=\u非洲？countries.Where（=>u.contraction==contraction.Africa）.FirstOrDefault（）。显示名称：SelectedCountry SelectedCountry=\u America？countries.Where（=>u.Continent==Continent.America）。FirstOrDefault（）。显示名称：SelectedCountry

调用所有属性的

OnPropertyChanged

private readonly ObservableCollection<Country> countries;
private ContinentViewModel selectedContinent;
private static string selectedCountry;
private int selectedRadioGroup;
private ObservableCollection<ContinentViewModel> continents;
private ListCollectionView countryView;
public event PropertyChangedEventHandler PropertyChanged;
private bool _All;
private bool _Africa;
private bool _America;
public bool All
{
    get
    {
        return _All;
    }
    set
    {
        _All = value;
        CountryView.Refresh();
        SelectedCountry = _All ? countries.FirstOrDefault().DisplayName : SelectedCountry;
        OnPropertyChanged("All");
    }
}

public bool Africa
{
    get
    {
        return _Africa;
    }
    set
    {
        _Africa = value;
        CountryView.Refresh();
        SelectedCountry = _Africa ? countries.Where(_ => _.Continent == Continent.Africa).FirstOrDefault().DisplayName : SelectedCountry;
        OnPropertyChanged("Africa");
    }
}

public bool America
{
    get
    {
        return _America;
    }
    set
    {
        _America = value;
        CountryView.Refresh();
        SelectedCountry = _America ? countries.Where(_ => _.Continent == Continent.America).FirstOrDefault().DisplayName : SelectedCountry;
        OnPropertyChanged("America");
    }
}

public MySettings()
{
    countries = new ObservableCollection<Country>(
        new[]
        {
        new Country() { Continent = Continent.Africa, DisplayName = "Algeria" },
        new Country() { Continent = Continent.Africa, DisplayName = "Egypt" },
        new Country() { Continent = Continent.Africa, DisplayName = "Chad" },
        new Country() { Continent = Continent.Africa, DisplayName = "Ghana" },
        new Country() { Continent = Continent.America, DisplayName = "Canada" },
        new Country() { Continent = Continent.America, DisplayName = "Greenland" },
        new Country() { Continent = Continent.America, DisplayName = "Haiti" }
        });
    CountryView = (ListCollectionView)CollectionViewSource.GetDefaultView(countries);
    CountryView.Filter += CountryFilter;
    Continents = new ObservableCollection<ContinentViewModel>(Enum.GetValues(typeof(Continent)).Cast<Continent>().Select(c => new ContinentViewModel { Model = c }));
}

private bool CountryFilter(object obj)
{
    var country = obj as Country;
    if (country == null) return false;
    if (All && !Africa && !America) return true;
    else if (!All && Africa && !America) return country.Continent == Continent.Africa;
    else if (!All && !Africa && America) return country.Continent == Continent.America;
    return true;
}

public ObservableCollection<ContinentViewModel> Continents
{
    get { return continents; }
    set
    {
        continents = value;
        OnPropertyChanged("Continents");
    }
}

public ListCollectionView CountryView
{
    get { return countryView; }
    set
    {
        countryView = value;
        OnPropertyChanged("CountryView");
    }
}

public class Country
{
    public string DisplayName { get; set; }
    public Continent Continent { get; set; }
}

public enum Continent
{
    All,
    Africa,
    America
}

public class ContinentViewModel
{
    public Continent Model { get; set; }
    public string DisplayName
    {
        get
        {
            return Enum.GetName(typeof(Continent), Model);
        }
    }
}

public ContinentViewModel SelectedContinent
{
    get { return selectedContinent; }
    set
    {
        selectedContinent = value;
        OnContinentChanged();
        this.OnPropertyChanged("SelectedContinent");
    }
}

private void OnContinentChanged()
{
    CountryView.Refresh();
}

public int SelectedRadioGroup
{
    get { return selectedRadioGroup; }
    set
    {
        selectedRadioGroup = value;
        OnPropertyChanged("SelectedRadioGroup");
    }
}

public string SelectedCountry
{
    get { return selectedCountry; }
    set
    {
        if (selectedCountry == value) return;
        selectedCountry = value;
        OnPropertyChanged("SelectedCountry");
    }
}

protected virtual void OnPropertyChanged(string propertyName)
{
    PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}

私人只读可观察收集国家/地区；
私有大陆视图模型选择大陆；
私有静态字符串selectedCountry；
私有int-selectedRadioGroup；
私人可观测收集大陆；
私有ListCollectionView国家视图；
公共事件属性更改事件处理程序属性更改；
私人住宅；
私人布尔(非洲),；
美国私立学校；
公共图书馆
{
得到
{
全部归还；
}
设置
{
_全部=价值；
CountryView.Refresh（）；
SelectedCountry=\u All？countries.FirstOrDefault（）。显示名称：SelectedCountry；
不动产变更（“全部”）；
}
}
公共布尔非洲
{
得到
{
返回非洲；
}
设置
{
_非洲=价值；
CountryView.Refresh（）；
SelectedCountry=\u Africa？countries.Where（\u=>\u.Continental==Continental.Africa）。FirstOrDefault（）。显示名称：SelectedCountry；
不动产变更（“非洲”）；
}
}
美国公共图书馆
{
得到
{
回归美国；
}
设置
{
_美国=价值；
CountryView.Refresh（）；
SelectedCountry=\u America？countries.Where（\u=>\u.Continental==Continental.America）。FirstOrDefault（）。显示名称：SelectedCountry；
房地产变更（“美国”）；
}
}
公共MySettings（）
{
国家/地区=新的可观测集合(
新[]
{
新国家（）{大陆=大陆.非洲，DisplayName=“阿尔及利亚”}，
新国家（）{大陆=大陆.非洲，DisplayName=“埃及”}，
新国家（）{大陆=大陆.非洲，DisplayName=“乍得”}，
新国家（）{大陆=大陆.非洲，DisplayName=“加纳”}，
new Country（）{大陆=大陆.美洲，DisplayName=“加拿大”}，
new Country（）{大陆=大陆.美洲，DisplayName=“格陵兰”}，
新国家（{大陆=大陆.美洲，DisplayName=“海地”}
});
CountryView=（ListCollectionView）CollectionViewSource.GetDefaultView（国家）；
CountryView.Filter+=CountryFilter；
大陆=新的ObservableCollection（Enum.GetValues（typeof（大陆））.Cast（）.Select（c=>new Continents ViewModel{Model=c}））；
}
私有布尔CountryFilter（对象对象对象）
{
var国家=obj作为国家；
如果（country==null）返回false；
如果（所有&&！非洲&&！美洲）返回true；
否则，如果（！All&&Africa&&！America）返回country.containment==containment.Africa；
如果（！All&&！Africa&&America）返回country.Continent==Continent.America；
返回true；
}
公共观测收集大陆
{
获取{返回大陆；}
设置
{
大陆=价值；
财产变更（“大陆”）；
}
}
公共列表集合视图CountryView
{
获取{return countryView；}
设置
{
countryView=价值；
OnPropertyChanged（“CountryView”）；
}
}
公营国家
{
公共字符串DisplayName{get；set；}
公共大陆{get；set；}
}
欧洲大陆公共普查
{
全部的
非洲，
美国
}
公共类模型
{
公共大陆模型{get；set；}
公共字符串显示名
{
得到
{
返回Enum.GetName（typeof（大陆），Model）；
}
}
}
公共大陆视图模型选定大陆
{
获取{返回SelectedContinental；}
设置
{
SelectedContinental=值；
OnContinentChanged（）；
此。OnProperty已更改（“选定大陆”）；
}
}
私有void OnContinentChanged（）
{
CountryView.Refresh（）；
}
public int SelectedRadioGroup
{
获取{return selectedRadioGroup；}
设置
{
selectedRadioGroup=值；
OnPropertyChanged（“SelectedRadioGroup”）；
}
}
公共字符串SelectedCountry
{
获取{返回selectedCountry；}
设置
{
如果（selectedCountry==值）返回；
selectedCountry=值；
已更改的房地产（“选定国家”）；
}
}
受保护的虚拟void OnPropertyChanged（字符串propertyName）
{
PropertyChanged？.Invoke（这是新的PropertyChangedEventArgs（propertyName））；
}

---

尝试将

ListCollectionView

创建为

CountryView=CollectionViewSource.GetDefaultView（国家）我必须将其转换为
CountryView=（ListCollectionView）CollectionViewSource.GetDefaultView（国家）并且它确实防止了主错误。但是，我现在得到错误
System.Windows.Data错误：4:找不到引用为“RelativeSource FindAncestor，AncestorType='System.Windows.Controls.ItemsControl'，AncestorLevel='1'的绑定源。BindingExpression:Path=HorizontalContentAlignment；DataItem=null；目标元素是“RibbonGalleryItem”（名称=“”）；目标属性为“HorizontalContentAlignment”（类型为“HorizontalAlignment”）
。这与我使用组合框时收到的消息相同。此外，当我单击单选按钮时，它会显示
MyNamespace.MySettings+Country
，而不是第一个选项，尽管国家确实出现在下拉菜单中。您已将SelectedCountry绑定到组合框的SelectedItem，无法在code Behind中查看属性。关于您收到的另一个错误，我看不到任何代码，请作为单独的问题提问在我的原始代码中。我现在已经将其包含在上面的代码中。谢谢您的帮助。尽管组合框仍然显示
namespace.MySettings+Country
，但仍然存在问题。我将您的代码复制到我的项目中，并删除了所有其他代码。如果运行代码，请选择一个国家（如Alg
<Grid>
    <DockPanel>
        <r:Ribbon DockPanel.Dock="Top" x:Name="Ribbon">
            <r:RibbonGroup Header="Continent" Width="260">
                <!--<ComboBox x:Name="CountryList" Width="100" ItemsSource="{Binding CountryView}" SelectedItem="{Binding SelectedCountry}" DisplayMemberPath="DisplayName"/>-->
                <r:RibbonComboBox x:Name="CountryList" Height="Auto" SelectionBoxWidth="230" VerticalAlignment="Center">
                    <r:RibbonGallery x:Name="cbSelectedCountry" SelectedValue="{Binding SelectedCountry, Mode=TwoWay}" SelectedValuePath="DisplayName" >
                        <r:RibbonGalleryCategory x:Name="cbCountryList" ItemsSource="{Binding CountryView}" DisplayMemberPath="DisplayName" />
                    </r:RibbonGallery>
                </r:RibbonComboBox>
                <WrapPanel>
                    <r:RibbonRadioButton x:Name="All" Label="All" GroupName="ContinentGroup" Height="Auto" Width="Auto" HorizontalAlignment="Left" IsChecked="{Binding Path=All}">
                    </r:RibbonRadioButton>
                    <r:RibbonRadioButton x:Name="Africa" Label="Africa" GroupName="ContinentGroup" Height="Auto" Width="Auto" HorizontalAlignment="Left" IsChecked="{Binding Path=Africa}">
                    </r:RibbonRadioButton>
                    <r:RibbonRadioButton x:Name="America" Label="America" GroupName="ContinentGroup" Height="Auto" Width="Auto" HorizontalAlignment="Left" IsChecked="{Binding Path=America}">
                    </r:RibbonRadioButton>
                </WrapPanel>
            </r:RibbonGroup>
        </r:Ribbon>
    </DockPanel>
</Grid>

using System;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Windows.Data;

public class MySettings : INotifyPropertyChanged
{
    private readonly ObservableCollection<Country> countries;
    private ContinentViewModel selectedContinent;
    private static string selectedCountry;
    private int selectedRadioGroup;
    private ObservableCollection<ContinentViewModel> continents;
    private ListCollectionView countryView;
    public event PropertyChangedEventHandler PropertyChanged;
    private bool _All;
    private bool _Africa;
    private bool _America;

    public bool All { get => _All; set { _All = value; CountryView.Refresh(); SelectedCountry = countries[0].ToString(); } }
    public bool Africa { get => _Africa; set { _Africa = value; CountryView.Refresh(); SelectedCountry = countries[0].ToString(); } }
    public bool America { get => _America; set { _America = value; CountryView.Refresh(); SelectedCountry = countries[0].ToString(); } }

    public MySettings()
    {
        countries = new ObservableCollection<Country>(
            new[]
            {
                new Country() { Continent = Continent.Africa, DisplayName = "Algeria" },
                new Country() { Continent = Continent.Africa, DisplayName = "Egypt" },
                new Country() { Continent = Continent.Africa, DisplayName = "Chad" },
                new Country() { Continent = Continent.Africa, DisplayName = "Ghana" },
                new Country() { Continent = Continent.America, DisplayName = "Canada" },
                new Country() { Continent = Continent.America, DisplayName = "Greenland" },
                new Country() { Continent = Continent.America, DisplayName = "Haiti" }
            });
        CountryView = (ListCollectionView)CollectionViewSource.GetDefaultView(countries);
        CountryView.Filter += CountryFilter;
        Continents = new ObservableCollection<ContinentViewModel>(Enum.GetValues(typeof(Continent)).Cast<Continent>().Select(c => new ContinentViewModel { Model = c }));
    }

    private bool CountryFilter(object obj)
    {
        var country = obj as Country;
        if (country == null) return false;
        if (All) return true;
        if (Africa) return country.Continent == Continent.Africa;
        if (America) return country.Continent == Continent.America;
        return true;
    }

    public ObservableCollection<ContinentViewModel> Continents
    {
        get { return continents; }
        set
        {
            continents = value;
        }
    }

    public ListCollectionView CountryView
    {
        get { return countryView; }
        set
        {
            countryView = value;
        }
    }

    public class Country
    {
        public string DisplayName { get; set; }
        public Continent Continent { get; set; }
    }

    public enum Continent
    {
        All,
        Africa,
        America
    }

    public class ContinentViewModel
    {
        public Continent Model { get; set; }
        public string DisplayName
        {
            get
            {
                return Enum.GetName(typeof(Continent), Model);
            }
        }
    }

    public ContinentViewModel SelectedContinent
    {
        get { return selectedContinent; }
        set
        {
            selectedContinent = value;
            OnContinentChanged();
            this.OnPropertyChanged("SelectedContinent");
        }
    }

    private void OnContinentChanged()
    {
        CountryView.Refresh();
    }

    public int SelectedRadioGroup
    {
        get { return selectedRadioGroup; }
        set
        {
            selectedRadioGroup = value;
        }
    }

    public string SelectedCountry
    {
        get { return selectedCountry; }
        set
        {
            if (selectedCountry == value) return;
            selectedCountry = value;
        }
    }

    protected virtual void OnPropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

private readonly ObservableCollection<Country> countries;
private ContinentViewModel selectedContinent;
private static string selectedCountry;
private int selectedRadioGroup;
private ObservableCollection<ContinentViewModel> continents;
private ListCollectionView countryView;
public event PropertyChangedEventHandler PropertyChanged;
private bool _All;
private bool _Africa;
private bool _America;
public bool All
{
    get
    {
        return _All;
    }
    set
    {
        _All = value;
        CountryView.Refresh();
        SelectedCountry = _All ? countries.FirstOrDefault().DisplayName : SelectedCountry;
        OnPropertyChanged("All");
    }
}

public bool Africa
{
    get
    {
        return _Africa;
    }
    set
    {
        _Africa = value;
        CountryView.Refresh();
        SelectedCountry = _Africa ? countries.Where(_ => _.Continent == Continent.Africa).FirstOrDefault().DisplayName : SelectedCountry;
        OnPropertyChanged("Africa");
    }
}

public bool America
{
    get
    {
        return _America;
    }
    set
    {
        _America = value;
        CountryView.Refresh();
        SelectedCountry = _America ? countries.Where(_ => _.Continent == Continent.America).FirstOrDefault().DisplayName : SelectedCountry;
        OnPropertyChanged("America");
    }
}

public MySettings()
{
    countries = new ObservableCollection<Country>(
        new[]
        {
        new Country() { Continent = Continent.Africa, DisplayName = "Algeria" },
        new Country() { Continent = Continent.Africa, DisplayName = "Egypt" },
        new Country() { Continent = Continent.Africa, DisplayName = "Chad" },
        new Country() { Continent = Continent.Africa, DisplayName = "Ghana" },
        new Country() { Continent = Continent.America, DisplayName = "Canada" },
        new Country() { Continent = Continent.America, DisplayName = "Greenland" },
        new Country() { Continent = Continent.America, DisplayName = "Haiti" }
        });
    CountryView = (ListCollectionView)CollectionViewSource.GetDefaultView(countries);
    CountryView.Filter += CountryFilter;
    Continents = new ObservableCollection<ContinentViewModel>(Enum.GetValues(typeof(Continent)).Cast<Continent>().Select(c => new ContinentViewModel { Model = c }));
}

private bool CountryFilter(object obj)
{
    var country = obj as Country;
    if (country == null) return false;
    if (All && !Africa && !America) return true;
    else if (!All && Africa && !America) return country.Continent == Continent.Africa;
    else if (!All && !Africa && America) return country.Continent == Continent.America;
    return true;
}

public ObservableCollection<ContinentViewModel> Continents
{
    get { return continents; }
    set
    {
        continents = value;
        OnPropertyChanged("Continents");
    }
}

public ListCollectionView CountryView
{
    get { return countryView; }
    set
    {
        countryView = value;
        OnPropertyChanged("CountryView");
    }
}

public class Country
{
    public string DisplayName { get; set; }
    public Continent Continent { get; set; }
}

public enum Continent
{
    All,
    Africa,
    America
}

public class ContinentViewModel
{
    public Continent Model { get; set; }
    public string DisplayName
    {
        get
        {
            return Enum.GetName(typeof(Continent), Model);
        }
    }
}

public ContinentViewModel SelectedContinent
{
    get { return selectedContinent; }
    set
    {
        selectedContinent = value;
        OnContinentChanged();
        this.OnPropertyChanged("SelectedContinent");
    }
}

private void OnContinentChanged()
{
    CountryView.Refresh();
}

public int SelectedRadioGroup
{
    get { return selectedRadioGroup; }
    set
    {
        selectedRadioGroup = value;
        OnPropertyChanged("SelectedRadioGroup");
    }
}

public string SelectedCountry
{
    get { return selectedCountry; }
    set
    {
        if (selectedCountry == value) return;
        selectedCountry = value;
        OnPropertyChanged("SelectedCountry");
    }
}

protected virtual void OnPropertyChanged(string propertyName)
{
    PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}