WPF 中网格可见性的多重绑定

Question

我有一个列表视图项我想折叠列表行中的一些项目我正在使用网格来编辑数据模板。我尝试使用参数的多重绑定但是我明白了 "DependencyProperty.UnsetValue" 很高兴有代码示例。

如果我使用 1 个参数就没问题。

谁能给我解释一下如何使用多重绑定会对代码示例感到满意。谢谢。

1 个参数的工作代码我可以使用此代码：

<ListView x:Name="LVGuiCoreBus" ScrollViewer.VerticalScrollBarVisibility="Auto" ScrollViewer.HorizontalScrollBarVisibility="Auto" MouseDown="LVGui_MouseDown"  Grid.Row="1" >               
    <ListView.ItemTemplate>
        <DataTemplate>
            <Grid Visibility="{Binding Source, Converter={StaticResource VisiblieGroupFilterBySourcecs}}">                                                                                                                              
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="130"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>
                    <ColumnDefinition Width="50"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>
                    <ColumnDefinition Width="50"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>
                    <ColumnDefinition Width="100"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>                                                      
                    <ColumnDefinition Width="70"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>
                    <ColumnDefinition Width="150"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>
                    <ColumnDefinition Width="150"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>
                    <ColumnDefinition Width="1*"></ColumnDefinition>
                </Grid.ColumnDefinitions>

                <TextBlock Text="{Binding DateNTimeStr}"  Foreground="Green" Grid.Column="0" />
                    <TextBlock Text="{Binding Source}" Foreground="{Binding Source,Converter={StaticResource CoreBusPanelModuleColorConverter}}" Grid.Column="2" Background="{ Binding Source, Converter={StaticResource BackGroundFilterConverterBySource}}" />
                    <TextBlock Text="{Binding Destination}" Foreground="{Binding Destination,Converter={StaticResource CoreBusPanelModuleColorConverter}}" Grid.Column="4" Background="{ Binding Destination, Converter={StaticResource BackGroundFilterConvertorByDestantation}}"  />
                    <TextBlock Text="{Binding Module}" Grid.Column="6" HorizontalAlignment="Center" Background="{ Binding Module, Converter={StaticResource BackGroundFilterByModule}}"   />
                    <TextBlock Text="{Binding Controll}" Grid.Column="8"  Background="{ Binding Controll, Converter={StaticResource BackGRoundFilterByControll}}"  />
                    <TextBlock Text="{Binding Command}" Grid.Column="10" HorizontalAlignment="Center"  Background="{ Binding Command, Converter={StaticResource BackGroundFilterByCommand}}"  />
                    <TextBlock Text="{Binding HSCommand}" Grid.Column="12" HorizontalAlignment="Center"  Background="{ Binding HSCommand, Converter={StaticResource BackGroundFilterByHsCommand}}"   />
                <TextBlock Text="{Binding Data_Str}"  Grid.Column="14"/>                                                                
            </Grid>
        </DataTemplate>
    </ListView.ItemTemplate>
    <ListView.ContextMenu>
        <ContextMenu x:Name="CMMenuCopy">
            <MenuItem x:Name="MCICopyLine" Header="Copy Line" Click="MCICopyLine_Click" ></MenuItem>
            <MenuItem x:Name="MCICopyText" Header="Copy Only Data Array" Click="MCICopyText_Click" ></MenuItem>
            <MenuItem x:Name="MCIClear" Header="Clear" Click="MCIClear_Click"></MenuItem>
        </ContextMenu>
    </ListView.ContextMenu>
</ListView>

代码多重绑定无效：

<ListView x:Name="LVGuiCoreBus" ScrollViewer.VerticalScrollBarVisibility="Auto" ScrollViewer.HorizontalScrollBarVisibility="Auto" MouseDown="LVGui_MouseDown"  Grid.Row="1" >               
    <ListView.ItemTemplate>
        <DataTemplate>
            <Grid>
                  <Grid.Visibility>
                                    <MultiBinding Converter="{StaticResource MultiValueConvertorVisibility}" UpdateSourceTrigger="PropertyChanged">
                                        <Binding ElementName="Source" Path="Visibility"  UpdateSourceTrigger="PropertyChanged"></Binding>
                                        <Binding ElementName="Destination" Path="Visibility"  UpdateSourceTrigger="PropertyChanged"></Binding>
                                        <Binding ElementName="Module" Path="Visibility"  UpdateSourceTrigger="PropertyChanged"></Binding>
                                        <Binding ElementName="Controll" Path="Visibility"  UpdateSourceTrigger="PropertyChanged"></Binding>
                                        <Binding ElementName="Command" Path="Visibility"  UpdateSourceTrigger="PropertyChanged"></Binding>
                                        <Binding ElementName="HSCommand" Path="Visibility"  UpdateSourceTrigger="PropertyChanged"></Binding>
                                    </MultiBinding>
                                </Grid.Visibility>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="130"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>
                    <ColumnDefinition Width="50"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>
                    <ColumnDefinition Width="50"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>
                    <ColumnDefinition Width="100"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>                                                      
                    <ColumnDefinition Width="70"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>
                    <ColumnDefinition Width="150"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>
                    <ColumnDefinition Width="150"></ColumnDefinition>
                    <ColumnDefinition Width="10"></ColumnDefinition>
                    <ColumnDefinition Width="1*"></ColumnDefinition>
                </Grid.ColumnDefinitions>

                <TextBlock Text="{Binding DateNTimeStr}"  Foreground="Green" Grid.Column="0" />
                    <TextBlock Text="{Binding Source}" Foreground="{Binding Source,Converter={StaticResource CoreBusPanelModuleColorConverter}}" Grid.Column="2" Background="{ Binding Source, Converter={StaticResource BackGroundFilterConverterBySource}}" />
                    <TextBlock Text="{Binding Destination}" Foreground="{Binding Destination,Converter={StaticResource CoreBusPanelModuleColorConverter}}" Grid.Column="4" Background="{ Binding Destination, Converter={StaticResource BackGroundFilterConvertorByDestantation}}"  />
                    <TextBlock Text="{Binding Module}" Grid.Column="6" HorizontalAlignment="Center" Background="{ Binding Module, Converter={StaticResource BackGroundFilterByModule}}"   />
                    <TextBlock Text="{Binding Controll}" Grid.Column="8"  Background="{ Binding Controll, Converter={StaticResource BackGRoundFilterByControll}}"  />
                    <TextBlock Text="{Binding Command}" Grid.Column="10" HorizontalAlignment="Center"  Background="{ Binding Command, Converter={StaticResource BackGroundFilterByCommand}}"  />
                    <TextBlock Text="{Binding HSCommand}" Grid.Column="12" HorizontalAlignment="Center"  Background="{ Binding HSCommand, Converter={StaticResource BackGroundFilterByHsCommand}}"   />
                <TextBlock Text="{Binding Data_Str}"  Grid.Column="14"/>                                                                
            </Grid>
        </DataTemplate>
    </ListView.ItemTemplate>
    <ListView.ContextMenu>
        <ContextMenu x:Name="CMMenuCopy">
            <MenuItem x:Name="MCICopyLine" Header="Copy Line" Click="MCICopyLine_Click" ></MenuItem>
            <MenuItem x:Name="MCICopyText" Header="Copy Only Data Array" Click="MCICopyText_Click" ></MenuItem>
            <MenuItem x:Name="MCIClear" Header="Clear" Click="MCIClear_Click"></MenuItem>
        </ContextMenu>
    </ListView.ContextMenu>
</ListView>
 public class MultiValueConvertorVisibility : IMultiValueConverter
 {
 public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        bool x = System.Convert.ToBoolean(values[0]);
        if (x)
        {
            return System.Windows.Visibility.Visible;
        }
        else
        {
            return System.Windows.Visibility.Collapsed;
        }
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
 }

Answer 1

从概念上讲，您缺少的最重要的部分是 IMultiValueConverter，因为可见性只是一个值，归根结底，您希望网格可见或不可见，因此您有告诉多重绑定如何将您的多个值组合成一个。

这里是一个如何让多重绑定起作用的例子：

网格：

<Window x:Class="WpfApp1.MainWindow"
    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:WpfApp1"
    mc:Ignorable="d"
    Title="MainWindow" Height="450" Width="800">
<Window.Resources>
    <local:MultiValueConverter x:Key="MyCustomConvertor"/>
</Window.Resources>


<Grid ShowGridLines="True">
    <Grid.Visibility>
        <MultiBinding Converter="{StaticResource MyCustomConvertor}" UpdateSourceTrigger="PropertyChanged">
            <Binding Path="Visibility"/>
        </MultiBinding>
    </Grid.Visibility>
    <Grid.RowDefinitions>
        <RowDefinition Height="100"/>
        <RowDefinition Height="100"/>
        <RowDefinition Height="100"/>
    </Grid.RowDefinitions>
</Grid>

您绑定的 Viewmodel：

using System.ComponentModel;
using System.Windows;

namespace WpfApp1
{
    class VM : INotifyPropertyChanged
    {
        #region WPF integration properties
        public event PropertyChangedEventHandler PropertyChanged;

        // Create the OnPropertyChanged method to raise the event
        protected void OnPropertyChanged(string name)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
        }
        #endregion

        private Visibility _visibility = Visibility.Hidden;
        public Visibility Visibility
        {
            get { return _visibility; }
            set
            {
                _visibility = value;
                OnPropertyChanged(nameof(Visibility));
            }
        }
    }
}

最后 MultiValueConverter 将多个可见性绑定转换为一个：

using System;
using System.Linq;
using System.Windows;
using System.Windows.Data;

namespace WpfApp1
{
    class MultiValueConverter : IMultiValueConverter
    {

        public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {

            if (values.Contains(Visibility.Collapsed))
            {
                return Visibility.Collapsed;
            }

            if (values.Contains(Visibility.Hidden))
            {
                return Visibility.Hidden;
            }

            return Visibility.Visible;
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }

    }
}

您可以在转换器中放置您认为合适的任何逻辑，我只是在不同的可见性类型上施加了一种层次结构。

WPF 中网格可见性的多重绑定

MultiBinding of grid visiblity in WPF

c#

wpf

multibinding