修改ObservableCollection時系結不起作用-有解無憂

我正在嘗試將 RadioButton 系結到ObservableCollection<Face>. 我已經做了幾個系結，它們都在作業。但是在那一個上，我無法理解出了什么問題。唯一不同的是，我嘗試為此使用轉換器。首先，我的 ObservableCollection 是 an ObservableCollection<int>，然后我將其更改為 an ObservableCollection<Face>，因為我認為問題是我無法系結 an ObservableCollection<int>，但沒有任何改變。

這是我的轉換器。我不想有一個 ConvertBack，但不能洗掉它？：

public class VisibleIfListIntContains : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if (parameter == null)
        {
            return false;
        }
        ObservableCollection<int> listInt = (ObservableCollection<int>)value;
        int value2 = System.Convert.ToInt32(parameter.ToString());
        //bool? retour = listInt.Contains(value2);
        return listInt.Contains(value2)
            ? Visibility.Visible
            : Visibility.Collapsed;
    }
    public object ConvertBack(object value, Type targetTypes, object parameter, System.Globalization.CultureInfo culture)
    {
        if ((bool)value == true)
        {
            return System.Convert.ToInt32(parameter);
        }
        else
        {
            return new List<int>();
        }
    }
}

然后是我系結的類：

public partial class Macro : INotifyPropertyChanged
{
    private ObservableCollection<int> listFacesAllowed = new ObservableCollection<int>();
    public ObservableCollection<int> ListFacesAllowed
    {
        get { return this.listFacesAllowed; }
        set
        {
            this.listFacesAllowed = value;
            this.NotifyPropertyChanged("ListFacesAllowed");
        }
    }
}

我這樣修改我的 ObservableCollection ：

private void setAvailableFaces()
{
    this.ListFacesAllowed.Clear();
    if (this.gpProfil == "I" || this.gpProfil == "H" || this.gpProfil == "U")
    {
        this.ListFacesAllowed.Add(0);
        this.ListFacesAllowed.Add(1);
        this.ListFacesAllowed.Add(2);
    }
    else if (this.gpProfil == "L")
    {
        this.ListFacesAllowed.Add(0);
        this.ListFacesAllowed.Add(2);
    }
    else if (this.gpProfil == "M")
    {
        this.ListFacesAllowed.Add(0);
        this.ListFacesAllowed.Add(1);
        this.ListFacesAllowed.Add(2);
        this.ListFacesAllowed.Add(3);
    }
    if (this.type==1)
    {
        if (this.isTraversingMacro)
        {
            if (this.gpProfil == "M")
            {
                this.ListFacesAllowed.Remove(1);
                this.ListFacesAllowed.Remove(3);
            }
            else if (gpProfil == "I" || gpProfil == "H" || gpProfil == "U")
            {
                this.ListFacesAllowed.Remove(1);
                if (this.name != "MV002" && this.name != "MV000")
                {
                    this.ListFacesAllowed.Remove(2);
                }
            }

        }
    }
    this.NotifyPropertyChanged("ListFacesAllowed");
    if (this.listFacesAllowed.Any() && !this.listFacesAllowed.Contains(this.face))
    {
        this.Face = this.listFacesAllowed[0];
    }
}

ObservableCollection 被修改，但轉換器從未執行。

這是 XAML 代碼：

<DataTemplate x:Key="TemplateType1">
        <Grid Background="{StaticResource WindowBackgroundColor}">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="auto"/>
                <ColumnDefinition Width="auto"/>
                <ColumnDefinition Width="200"/>
            </Grid.ColumnDefinitions>
            <Grid Margin="10,10,20,10">
                <Grid.RowDefinitions>
                    <RowDefinition Height="auto"/>
                    <RowDefinition Height="auto"/>
                    <RowDefinition Height="auto"/>
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="100"/>
                    <ColumnDefinition Width="*"/>
                </Grid.ColumnDefinitions>
                <Grid Grid.RowSpan="2">
                    <Grid.RowDefinitions>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="auto"/>
                    </Grid.RowDefinitions>
                    <ListView ItemsSource="{Binding}" SelectedItem="{Binding DataContext.SelectedMacro,   
                        RelativeSource={RelativeSource AncestorType=Window},Mode=TwoWay}"  Margin="3" Width="auto">
                        <ListView.View>
                            <GridView>
                                <GridViewColumn Header="{x:Static p:Resources.Name}" Width="auto" DisplayMemberBinding="{Binding Name}"/>
                            </GridView>
                        </ListView.View>
                    </ListView>
                    <Button Grid.Row="1" HorizontalAlignment="Left" Margin="3,10,3,3" Click="AddMacro_Click">
                        <Image Source="../img/image_add.png" Width="40"/>
                    </Button>
                </Grid>

                <Grid Grid.Column="1">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="auto"/>
                        <ColumnDefinition Width="*"/>
                        <ColumnDefinition Width="auto"/>
                    </Grid.ColumnDefinitions>
                    <Grid Grid.Column="0">
                        <Grid.RowDefinitions>
                            <RowDefinition Height="*"/>
                            <RowDefinition Height="20"/>
                            <RowDefinition Height="*"/>
                            <RowDefinition Height="*"/>
                            <RowDefinition Height="*"/>
                            <RowDefinition Height="*"/>
                            <RowDefinition Height="*"/>
                            <RowDefinition Height="*"/>
                            <RowDefinition Height="*"/>
                        </Grid.RowDefinitions>
                        <CheckBox Grid.Row="0" IsChecked="{Binding DataContext.SelectedMacro.IsTraversingMacro, RelativeSource={RelativeSource AncestorType=Window},Mode=TwoWay}" 
                                    Content="{x:Static p:Resources.Traversing}"
                                    Margin="3"/>

                        <RadioButton Grid.Row="2" IsChecked="{Binding DataContext.SelectedMacro.Face, RelativeSource={RelativeSource AncestorType=Window},Converter={StaticResource isIntEqual},ConverterParameter=0}" 
                                    Visibility="{Binding DataContext.SelectedMacro.ListFacesAllowed, RelativeSource={RelativeSource AncestorType=Window},Converter={StaticResource visibleIfListIntContains},ConverterParameter=0}"
                                    Content="{x:Static p:Resources.Web}"
                                    Margin="3"/>
                        <RadioButton Grid.Row="3" IsChecked="{Binding DataContext.SelectedMacro.Face, RelativeSource={RelativeSource AncestorType=Window},Converter={StaticResource isIntEqual},ConverterParameter=1}" 
                                    Visibility="{Binding DataContext.SelectedMacro.ListFacesAllowed, RelativeSource={RelativeSource AncestorType=Window},Converter={StaticResource visibleIfListIntContains},ConverterParameter=1}"
                                    Content="{x:Static p:Resources.FlangeTop}"
                                    Margin="3"/>
                        <RadioButton Grid.Row="4" IsChecked="{Binding DataContext.SelectedMacro.Face, RelativeSource={RelativeSource AncestorType=Window},Converter={StaticResource isIntEqual},ConverterParameter=2}" 
                                    Visibility="{Binding DataContext.SelectedMacro.ListFacesAllowed, RelativeSource={RelativeSource AncestorType=Window},Converter={StaticResource visibleIfListIntContains},ConverterParameter=2}"
                                    Content="{x:Static p:Resources.FlangeBottom}"
                                    Margin="3"/>
                        <RadioButton Grid.Row="5" IsChecked="{Binding DataContext.SelectedMacro.Face, RelativeSource={RelativeSource AncestorType=Window},Converter={StaticResource isIntEqual},ConverterParameter=3}" 
                                    Visibility="{Binding DataContext.SelectedMacro.ListFacesAllowed, RelativeSource={RelativeSource AncestorType=Window},Converter={StaticResource visibleIfListIntContains},ConverterParameter=3}"
                                    Content="{x:Static p:Resources.WebBack}"
                                    Margin="3"/>
                    </Grid>
                    <Grid Grid.Column="2" HorizontalAlignment="Right">
                        <Grid.RowDefinitions>
                            <RowDefinition Height="*"/>
                            <RowDefinition Height="*"/>

                        </Grid.RowDefinitions>
                        <RadioButton Visibility="{Binding DataContext.SelectedMacro.BottomChoice,   
                        RelativeSource={RelativeSource AncestorType=Window}, Converter={StaticResource BoolToVisConverter}}"
                        Content="{x:Static p:Resources.Top}"
                        GroupName="radioGroup31" Margin="0,3,0,3"
                        IsChecked="{Binding DataContext.SelectedMacro.Bottom,   
                        RelativeSource={RelativeSource AncestorType=Window},
                                            Converter={StaticResource InverseBoolRadioConverter}}" />
                        <RadioButton Grid.Row="1" Visibility="{Binding DataContext.SelectedMacro.BottomChoice,   
                        RelativeSource={RelativeSource AncestorType=Window}, Converter={StaticResource BoolToVisConverter}}"
                        Content="{x:Static p:Resources.Bottom}"
                        GroupName="radioGroup32" Margin="0,3,0,3"
                        IsChecked="{Binding DataContext.SelectedMacro.Bottom,   
                        RelativeSource={RelativeSource AncestorType=Window}, Converter={StaticResource BoolRadioConverter}}" />
                    </Grid>

                </Grid>
                <Grid Grid.Column="1" Grid.Row="1">
                    <Grid.RowDefinitions>
                        <RowDefinition Height="auto"/>
                        <RowDefinition Height="auto"/>
                    </Grid.RowDefinitions>
                    <Label Content="{Binding DataContext.SelectedMacro.Name,   
                        RelativeSource={RelativeSource AncestorType=Window}}" HorizontalAlignment="Center" FontSize="30"/>
                    <Image Grid.Row="1" Width="250" Height="250" Source="{Binding DataContext.SelectedMacro.ImageName,   
                        RelativeSource={RelativeSource AncestorType=Window}}"/>
                </Grid>
                <Grid Grid.Row="2" Grid.Column="1">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="80"/>
                        <ColumnDefinition Width="*"/>
                        <ColumnDefinition Width="80"/>
                    </Grid.ColumnDefinitions>
                    <Button Content="{x:Static p:Resources.Delete}" Click="DeleteMacro_Click" Margin="3" >
                        <Button.Style>
                            <Style TargetType="Button" BasedOn="{StaticResource {x:Type Button}}">
                                <Style.Triggers>
                                    <DataTrigger Binding="{Binding DataContext.SelectedMacro.Name,RelativeSource={RelativeSource AncestorType=Window}, Mode=OneWay}" Value="">
                                        <Setter Property="Button.IsEnabled" Value="False" />
                                    </DataTrigger>
                                </Style.Triggers>
                            </Style>
                        </Button.Style>
                    </Button>
                    <Button Content="{x:Static p:Resources.Change}" Grid.Column="2" Click="EditMacro_Click" Margin="3">
                        <Button.Style>
                            <Style TargetType="Button" BasedOn="{StaticResource {x:Type Button}}">
                                <Style.Triggers>
                                    <DataTrigger Binding="{Binding DataContext.SelectedMacro.Name,RelativeSource={RelativeSource AncestorType=Window}, Mode=OneWay}" Value="">
                                        <Setter Property="Button.Content" Value="{x:Static p:Resources.Add}" />
                                    </DataTrigger>
                                </Style.Triggers>
                            </Style>
                        </Button.Style>
                    </Button>
                </Grid>

            </Grid>
            <Grid Margin="20,10,10,10" Grid.Column="2">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="auto"/>
                    <ColumnDefinition Width="auto"/>
                </Grid.ColumnDefinitions>
                <ItemsControl Grid.Column="0" ItemsSource="{Binding DataContext.SelectedMacro.ListParams,RelativeSource={RelativeSource AncestorType=Window}}">
                    <ItemsControl.ItemTemplate>
                        <DataTemplate>
                            <Grid Margin="0,0,0,5" Height="30">
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="auto" />
                                </Grid.ColumnDefinitions>
                                <Label Content="{Binding Name}" VerticalAlignment="Center"/>
                            </Grid>
                        </DataTemplate>
                    </ItemsControl.ItemTemplate>
                </ItemsControl>
                <ItemsControl Grid.Column="1" ItemsSource="{Binding DataContext.SelectedMacro.ListParams,RelativeSource={RelativeSource AncestorType=Window}, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
                    <ItemsControl.ItemTemplate>
                        <DataTemplate>
                            <Grid Margin="0,0,0,5" Height="30">
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="100" />
                                </Grid.ColumnDefinitions>
                                <TextBox Grid.Column="1" Text="{Binding Valeur}" PreviewTextInput="CheckIsPositiveDouble" VerticalAlignment="Center" />
                            </Grid>
                        </DataTemplate>
                    </ItemsControl.ItemTemplate>
                </ItemsControl>
            </Grid>
        </Grid>
    </DataTemplate>

模板中的所有系結都作業良好，除了那些DataContext.SelectedMacro.ListFacesAllowed

uj5u.com熱心網友回復：

據我了解，您需要檢查 Id 集合中是否存在 UI 元素 Id。如果它在那里，然后安裝它的可見性。

如果我理解正確，那么明顯的問題是您誤解了 Binding 的邏輯。
系結將在第一次加載時起作用，對于后續更新，您需要通知已發生更改。
而且由于您系結到整個集合并且需要全部檢查，因此當您更改其任何元素時，您需要替換集合實體。
因為否則系結將（有條件地）檢查它是否是集合的另一個實體。如果相同，它不會更新，即使集合的元素已經不同。

簡單的例子：

using Simplified;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Core2022.SO.SiegfriedV
{
    public class IntsViewModel : BaseInpc
    {
        private HashSet<int> _numbers = new HashSet<int>(Enumerable.Range(0, 10));

        public HashSet<int> Numbers { get => _numbers; private set => Set(ref _numbers, value); }

        public IntsViewModel()
        {
            AddIntCommand = new RelayCommand<int>(num =>
            {
                HashSet<int> copy = new HashSet<int>(Numbers);
                copy.Add(num);
                Numbers = copy;
            });

            RemoveIntCommand = new RelayCommand<int>(num =>
            {
                HashSet<int> copy = new HashSet<int>(Numbers);
                copy.Remove(num);
                Numbers = copy;
            });
        }

        public RelayCommand<int> AddIntCommand { get; }
        public RelayCommand<int> RemoveIntCommand { get; }
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Globalization;
using System.Windows;
using System.Windows.Data;

namespace Core2022.SO.SiegfriedV
{
    [ValueConversion(typeof(ISet<int>), typeof(Visibility))]
    public class VisibleIfListIntContains : IValueConverter
    {
        private static readonly Int32Converter converter = new Int32Converter();
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value is not ISet<int> ints)
                return DependencyProperty.UnsetValue;

            if (parameter is not int num)
            {
                if (!converter.IsValid(parameter))
                    return DependencyProperty.UnsetValue;
                num = (int)(converter.ConvertFrom(parameter) ?? throw new Exception("God knows what happened."));
            }

            return ints.Contains(num)
                ? Visibility.Visible
                : Visibility.Collapsed;
        }

        // The reverse conversion in such logic, in principle, will not work,
        // since it is impossible to replace the collection itself with a new instance from the converter.
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }

        private VisibleIfListIntContains() { }
        public static VisibleIfListIntContains Instance { get; } = new VisibleIfListIntContains();
    }
}

namespace Core2022.SO.SiegfriedV
{
    // Helper class for automatically converting a string (TextBox.Text) to an integer.
    public class DataProxy
    {
        public int Number { get; set; }
    }
}

<Window x:Class="Core2022.SO.SiegfriedV.IntsWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:Core2022.SO.SiegfriedV"
        mc:Ignorable="d"
        Title="IntsWindow" Height="450" Width="800"
        DataContext="{DynamicResource vm}">
    <Window.Resources>
        <local:IntsViewModel x:Key="vm"/>
        <local:DataProxy x:Key="proxy"/>
    </Window.Resources>
    <UniformGrid Columns="2">
        <UniformGrid HorizontalAlignment="Center" Columns="1">
            <TextBlock Text="0" Visibility="{Binding Numbers, Converter={x:Static local:VisibleIfListIntContains.Instance}, ConverterParameter=0}" VerticalAlignment="Center"/>
            <TextBlock Text="1" Visibility="{Binding Numbers, Converter={x:Static local:VisibleIfListIntContains.Instance}, ConverterParameter=1}" VerticalAlignment="Center"/>
            <TextBlock Text="2" Visibility="{Binding Numbers, Converter={x:Static local:VisibleIfListIntContains.Instance}, ConverterParameter=2}" VerticalAlignment="Center"/>
            <TextBlock Text="3" Visibility="{Binding Numbers, Converter={x:Static local:VisibleIfListIntContains.Instance}, ConverterParameter=3}" VerticalAlignment="Center"/>
            <TextBlock Text="4" Visibility="{Binding Numbers, Converter={x:Static local:VisibleIfListIntContains.Instance}, ConverterParameter=4}" VerticalAlignment="Center"/>
            <TextBlock Text="5" Visibility="{Binding Numbers, Converter={x:Static local:VisibleIfListIntContains.Instance}, ConverterParameter=5}" VerticalAlignment="Center"/>
            <TextBlock Text="6" Visibility="{Binding Numbers, Converter={x:Static local:VisibleIfListIntContains.Instance}, ConverterParameter=6}" VerticalAlignment="Center"/>
            <TextBlock Text="7" Visibility="{Binding Numbers, Converter={x:Static local:VisibleIfListIntContains.Instance}, ConverterParameter=7}" VerticalAlignment="Center"/>
            <TextBlock Text="8" Visibility="{Binding Numbers, Converter={x:Static local:VisibleIfListIntContains.Instance}, ConverterParameter=8}" VerticalAlignment="Center"/>
            <TextBlock Text="9" Visibility="{Binding Numbers, Converter={x:Static local:VisibleIfListIntContains.Instance}, ConverterParameter=9}" VerticalAlignment="Center"/>
        </UniformGrid>
        <UniformGrid Columns="1">
            <TextBox VerticalAlignment="Center" Width="40" HorizontalContentAlignment="Center"
                     Text="{Binding Number, Source={StaticResource proxy}}"/>
            <UniformGrid Columns="2" HorizontalAlignment="Center" VerticalAlignment="Top">
                <Button Content="Add" Padding="15 5" Margin="10"
                        Command="{Binding AddIntCommand}"
                        CommandParameter="{Binding Number, Source={StaticResource proxy}}"/>
                <Button Content="Remove" Padding="15 5" Margin="10"
                        Command="{Binding RemoveIntCommand}"
                        CommandParameter="{Binding Number, Source={StaticResource proxy}}"/>
            </UniformGrid>
        </UniformGrid>
    </UniformGrid>
</Window>

使用了BaseInpc 和 RelayCommand 類。

PS如果我誤解了你的任務，請更詳細地解釋它對你很重要的細節。

與澄清問題有關的答案的補充

據我了解您的代碼，我的解釋可以這樣應用：

    public partial class Macro : BaseInpc
    {
        private IEnumerable<int> _listFacesAllowed = Enumerable.Empty<int>();
        public IEnumerable<int> ListFacesAllowed
        {
            get => _listFacesAllowed;
            set => Set(ref _listFacesAllowed, value);
        }

    private void setAvailableFaces()
    {
        if (this.gpProfil == "I" || this.gpProfil == "H" || this.gpProfil == "U")
        {
            ListFacesAllowed = ListFacesAllowed.Concat(new int[] { 0, 1, 3 }).Distinct().ToArray();
        }
        else if (this.gpProfil == "L")
        {
            ListFacesAllowed = ListFacesAllowed.Concat(new int[] { 0, 2 }).Distinct().ToArray();
        }
        else if (this.gpProfil == "M")
        {
            ListFacesAllowed = ListFacesAllowed.Concat(new int[] { 0, 1, 2, 3 }).Distinct().ToArray();
        }
        if (this.type == 1)
        {
            if (this.isTraversingMacro)
            {
                if (this.gpProfil == "M")
                {
                    ListFacesAllowed = ListFacesAllowed.Except(new int[] { 0, 3 }).Distinct().ToArray();
                }
                else if (gpProfil == "I" || gpProfil == "H" || gpProfil == "U")
                {
                    if (this.name != "MV002" && this.name != "MV000")
                    {
                        ListFacesAllowed = ListFacesAllowed.Except(new int[] { 1, 2 }).Distinct().ToArray();
                    }
                    else
                    {
                        ListFacesAllowed = ListFacesAllowed.Except(new int[] { 1 }).Distinct().ToArray();
                    }
                }

            }
        }
    }

    [ValueConversion(typeof(ISet<int>), typeof(Visibility))]
    public class VisibleIfListIntContains : IValueConverter
    {
        private static readonly Int32Converter converter = new Int32Converter();
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value is not IEnumerable<int> ints)
                return DependencyProperty.UnsetValue;

            if (parameter is not int num)
            {
                if (!converter.IsValid(parameter))
                    return DependencyProperty.UnsetValue;
                num = (int)(converter.ConvertFrom(parameter) ?? throw new Exception("God knows what happened."));
            }

            return ints.Contains(num)
                ? Visibility.Visible
                : Visibility.Collapsed;
        }

        // The reverse conversion in such logic, in principle, will not work,
        // since it is impossible to replace the collection itself with a new instance from the converter.
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }

        private VisibleIfListIntContains() { }
        public static VisibleIfListIntContains Instance { get; } = new VisibleIfListIntContains();
    }

該方法的稍微更優化的實作：

    private static readonly ReadOnlyCollection<int>
        facesEmpty = Array.AsReadOnly(Array.Empty<int>()),
        faces013 = Array.AsReadOnly(new int[] { 0, 1, 3 }),
        faces02 = Array.AsReadOnly(new int[] { 0, 2 }),
        faces0123 = Array.AsReadOnly(new int[] { 0, 1, 2, 3 }),
        faces03 = Array.AsReadOnly(new int[] { 0, 3 }),
        faces12 = Array.AsReadOnly(new int[] { 1, 2}),
        faces1 = Array.AsReadOnly(new int[] { 1 });

    private void setAvailableFaces()
    {
        IEnumerable<int> newlistFaces = this.gpProfil switch
        {
            "I" or "H" or "U" => faces013,
            "L" => faces02,
            "M" => faces0123,
            _ => facesEmpty
        };

        if (newlistFaces != facesEmpty && this.type == 1 && this.isTraversingMacro)
        {
            newlistFaces = this.gpProfil switch
            {
                "M" => newlistFaces.Except(faces03),
                "I" or "H" or "U" => this.name switch
                {
                    "MV002" or "MV000" => newlistFaces.Except(faces1),
                    _ => newlistFaces.Except(faces12)
                },
                _=> newlistFaces
            };
        }
        ListFacesAllowed = newlistFaces;
    }

轉載請註明出處，本文鏈接：https://www.uj5u.com/ruanti/516383.html

標籤：C＃wpf捆绑可观察的集合转换器

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