基于 RadioButton 的 C# WPF 筛选器组合框

Question

我有一个带有功能区组合框的 WPF 项目，其中显示了我尝试根据所选单选按钮选项筛选的国家/地区列表(全部、非洲、亚洲、欧洲(。我的代码基于 WPF 中的 COMBOBOX 过滤和 MVVM，它使用 ComboBox 选择一个大洲并在列表框中显示过滤的国家/地区，但我在将其转换为使用 RadioButton 时遇到了问题。

1. XAML isChecked="..."似乎会导致 EnumBooleanConverter 中出现"输入字符串格式不正确"错误的行，但如果我将它们更改为"转换器参数 = 0"，应用程序将运行。我基于如何将单选按钮绑定到枚举？。
2. 默认的国家/地区列表最初显示在 ComboBox 中，但不显示默认国家/地区，而是显示为空白。
3. 单击单选按钮对列表没有影响。

显然我做错了什么，但我不知道是什么。你能帮忙吗？

XAML：

<ribbon:RibbonRadioButton x:Name="AllContinents"
GroupName="Continents"
IsChecked="{Binding Path=SelectedRadioGroup, Converter={StaticResource EnumBooleanConverter}, ConverterParameter={x:Static local:mySettings+Continent.All}}"> <= Causes run error
</ribbon:RibbonRadioButton>
<ribbon:RibbonRadioButton x:Name="Africa"
GroupName="Continents"
IsChecked="{Binding Path=SelectedRadioGroup, Converter={StaticResource EnumBooleanConverter}, ConverterParameter={x:Static local:mySettings+Continent.Africa}}"> <= Causes run error
</ribbon:RibbonRadioButton>

C# 代码隐藏 (数据上下文(：

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Windows.Data;
public class MySettings : INotifyPropertyChanged
{
private ObservableCollection<Country> countries;
private ContinentViewModel selectedContinent;
public ListCollectionView CountryView { get; set; }
public event PropertyChangedEventHandler PropertyChanged;
public ObservableCollection<ContinentViewModel> Continents { get; set; } 
private static string selectedCountry = "Germany"; // Default country
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.Europe, DisplayName = "France" }
new Country() { Continent = Continent.Europe, DisplayName = "Germany" }
});
CountryView = new ListCollectionView(countries);
CountryView.Filter = o => selectedContinent == null || ((Country)o).Continent == selectedContinent.Model;
Continents = new ObservableCollection<ContinentViewModel>(Enum.GetValues(typeof(Continent)).Cast<Continent>().Select(c => new ContinentViewModel { Model = c}));
}
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,
Asia,
Europe,
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;
OnPropertyChanged(nameof(SelectedCountry));
}
}
protected virtual void OnPropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = this.PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
public class EnumBooleanConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
int integer = (int)value;
return integer == int.Parse(parameter.ToString()) ? true : (object)false;  <= Error:Input string was not in a correct format
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return ((bool)value) ? parameter : Binding.DoNothing;
}
}

Answer 1

我会为每个单选按钮提供一个布尔属性，而不是使用转换器。然后检查您的过滤器。

CountryView.Filter += CountryFilter;

private bool _All;
private bool _Africa;
private bool _Asia;
private bool _Europe;
private bool _America;
public bool All { get=>_All; set { _All=value; CountryView.Refresh(); } }
public bool Africa { get=> _Africa; set { _Africa=value; CountryView.Refresh(); } }
public bool Asia { get=> _Asia; set { _Asia=value; CountryView.Refresh(); } }
public bool Europe { get=> _Europe; set { _Europe=value; CountryView.Refresh(); } }
public bool America { get=> _America; set { _America=value; CountryView.Refresh() ;} }}
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 (Asia) return country.Continent == Continent.Asia;
if (Europe) return country.Continent == Continent.Europe;
if (America) return country.Continent == Continent.America;
return true;
}