Wpf 尝试将ComboBox SelectedItem绑定到GroupBox可见性属性

尝试基于ComboBox的SelectedItem绑定GroupBox的可见性属性。我的组合框显示

FreqTypeCollection

，我想隐藏/显示相应的GroupBox

        public Dictionary<FreqType, string> FreqTypeCollection
        {
            get
            {
                var d =
                    new Dictionary<FreqType, string>()
                        {
                            {FreqType.OneTimeOnly, "One time only"},
                            {FreqType.Daily, "Recurring - Daily"},
                            {FreqType.Weekly, "Recurring - Weekly"},
                            {FreqType.Monthly, "Recurring - Monthly"},
                            {FreqType.MonthlyRelativeToFreqInterval, "Monthly relative"}
                        };
                return d;
            }
        }

<ComboBox Name="ScheduleTypeComboBox" ItemsSource="{Binding Path=FreqTypeCollection}" DisplayMemberPath="Value" 
    SelectedValuePath="Key" SelectedValue="{Binding Path=freq_type, Mode=TwoWay, Converter={StaticResource FreqTypeConverter}}">
<GroupBox Header="One time only" Name="OneTimeOnlyGroupBox" Visibility="Collapsed">
    <GroupBox.Style>
        <Style TargetType="GroupBox">
            <Style.Triggers>
                <DataTrigger Binding="{Binding Path=freq_type}" Value="1">
                    <Setter Property="Visibility" Value="Visible"></Setter>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </GroupBox.Style>
</GroupBox>
<GroupBox Header="Recurring-Daily" Name="DailyGroupBox" Visibility="Collapsed">
    <GroupBox.Style>
        <Style TargetType="GroupBox">
            <Style.Triggers>
                <DataTrigger Binding="{Binding Path=freq_type}" Value="2">
                    <Setter Property="Visibility" Value="Visible"></Setter>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </GroupBox.Style>
</GroupBox>

 class FreqTypeConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if (value == null)
                return null;
            else
            {
                FreqType f = (FreqType)value;
                return f;
            }
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            int rValue=(int)value;
            return rValue;
        }
    }

public enum FreqType
{
    [Display(Name = "One time only")]
    [Description("Task will be scheduled one time only.")]
    OneTimeOnly = 1,
    [Display(Name = "Daily")]
    [Description("Recurring daily.")]
    Daily = 4,
    [Display(Name = "Weekly")]
    [Description("Recurring weekly.")]
    Weekly = 8,
    [Display(Name = "Monthly")]
    [Description("Recurring monthly.")]
    Monthly = 16,
    [Display(Name = "Monthly relative")]
    [Description("Recurring monthly relatively.")]
    MonthlyRelativeToFreqInterval = 32,
};  

公共字典类型集合
{
得到
{
变量d=
新字典（）
{
{FreqType.OneTimeOnly，“仅限一次”}，
{FreqType.Daily，“循环-每日”}，
{FreqType.Weekly，“循环-每周”}，
{FreqType.Monthly，“循环-每月”}，
{FreqType.MonthlyRelativeToFreqInterval，“每月相对”}
};
返回d；
}
}
类FreqTypeConverter:IValueConverter
{
公共对象转换（对象值、类型targetType、对象参数、System.Globalization.CultureInfo区域性）
{
如果（值==null）
返回null；
其他的
{
FreqType f=（FreqType）值；
返回f；
}
}
公共对象转换回（对象值、类型targetType、对象参数、System.Globalization.CultureInfo区域性）
{
int rValue=（int）值；
返回右值；
}
}
公共枚举类型
{
[显示（Name=“仅一次”）]
[说明（“任务只安排一次。”）]
OneTimeOnly=1，
[显示（Name=“每日”）]
[说明（“每日重复”）
每日=4，
[显示（Name=“Weekly”）]
[说明（“每周定期”）]
每周=8，
[显示（Name=“每月”）]
[说明（“每月定期”）]
每月=16，
[显示（Name=“每月相对”）]
[说明（“每月相对重复。”）]
月相对频率间隔=32，
};  

您在xaml中有一些错误

触发器应该绑定到组合框中的SelectedIndex（在您的情况下，触发器如何知道组合框中的新选定项？）

Binding=“{Binding Path=SelectedIndex，ElementName=ScheduleTypeComboBox}”

触发器应该为属性的默认值设置setter

Setter Property=“可见性”Value=“折叠”

都是代码：

 <ComboBox x:Name="ScheduleTypeComboBox" ItemsSource="{Binding Path=FreqTypeCollection}" DisplayMemberPath="Value" 
    SelectedValuePath="Key" SelectedValue="{Binding Path=freq_type, Mode=TwoWay, Converter={StaticResource FreqTypeConverter}}"/>
                <GroupBox Header="One time only" x:Name="OneTimeOnlyGroupBox">
                    <GroupBox.Style>
                        <Style TargetType="GroupBox">
                        <Setter Property="Visibility" Value="Collapsed" />
                        <Style.Triggers>
                            <DataTrigger Binding="{Binding Path=SelectedIndex, ElementName=ScheduleTypeComboBox}" Value="0">
                                    <Setter Property="Visibility" Value="Visible"></Setter>
                                </DataTrigger>
                            </Style.Triggers>
                        </Style>
                    </GroupBox.Style>
                </GroupBox>
                <GroupBox Header="Recurring-Daily" x:Name="DailyGroupBox">
                    <GroupBox.Style>
                        <Style TargetType="GroupBox">
                        <Setter Property="Visibility" Value="Collapsed" />
                        <Style.Triggers>
                            <DataTrigger Binding="{Binding Path=SelectedItem, ElementName=ScheduleTypeComboBox}" Value="1">
                                    <Setter Property="Visibility" Value="Visible"></Setter>
                                </DataTrigger>
                            </Style.Triggers>
                        </Style>
                    </GroupBox.Style>
                </GroupBox>