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添付プロパティを使用するとトリガーが更新されません。まずWPF：DataTriggerを手動で更新する方法
Window1.xaml
<Window x:Class="proj1.Window1"
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:proj1"
mc:Ignorable="d"
Title="Window1" Height="300" Width="300">
<Window.Resources>
<Style TargetType="ListView" x:Key="style1">
<Setter Property="View">
<Setter.Value>
<GridView>
<GridViewColumn Header="1" DisplayMemberBinding="{Binding one}" Width="100" />
<GridViewColumn Header="2" DisplayMemberBinding="{Binding two}" Width="100" />
</GridView>
</Setter.Value>
</Setter>
<EventSetter Event="GridViewColumnHeader.Click" Handler="ColumnHeader_Click"/>
<Style.Triggers>
<!--
<Trigger Property="Column.local:TestClass.Flag" Value="True">
<Setter Property="Foreground" Value="Red" />
</Trigger>
-->
</Style.Triggers>
</Style>
<Style TargetType="ListView" x:Key="style2">
<Setter Property="View">
<Setter.Value>
<GridView>
<GridViewColumn Header="1" DisplayMemberBinding="{Binding one}" Width="100" />
<GridViewColumn Header="2" DisplayMemberBinding="{Binding two}" Width="100" />
</GridView>
</Setter.Value>
</Setter>
<EventSetter Event="GridViewColumnHeader.Click" Handler="ColumnHeader_Click"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Column, RelativeSource={RelativeSource Self}, Converter={x:Static local:TestClass.Converter}}" Value="True">
<Setter Property="Foreground" Value="Red" />
</DataTrigger>
</Style.Triggers>
</Style>
</Window.Resources>
<Grid>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<ListView Grid.Row="0" Style="{StaticResource style1}" ItemsSource="{Binding items}" />
<ListView Grid.Row="1" Style="{StaticResource style2}" ItemsSource="{Binding items}" />
</Grid>
</Window>
Window1.xaml.cs
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
namespace proj1
{
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
// set dummy data
this.DataContext = new
{
items = new[]
{
new {
one = "A",
two = "a",
},
new {
one = "B",
two = "b",
},
new {
one = "C",
two = "c",
},
new {
one = "D",
two = "d",
},
}
};
}
/// <summary>
/// cannot change!
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ColumnHeader_Click(object sender, RoutedEventArgs e)
{
var column_header = e.OriginalSource as GridViewColumnHeader;
if (column_header == null) return;
var column = column_header.Column;
if (column == null) return;
TestClass.Setflag(column, !TestClass.GetFlag(column));
// debug print
Console.WriteLine($"{column_header.Content}/{TestClass.GetFlag(column)}");
}
}
/// <summary>
/// Define 'Flag' AttachedProprety and IValueCoverter which pick
/// 'Flag' AttachedProperty from a DependencyObject
/// </summary>
public class TestClass
{
public static bool GetFlag(DependencyObject obj)
{
return (bool)obj.GetValue(FlagProperty);
}
public static void Setflag(DependencyObject obj, bool value)
{
obj.SetValue(FlagProperty, value);
}
// Using a DependencyProperty as the backing store for flag. This enables animation, styling, binding, etc...
public static readonly DependencyProperty FlagProperty =
DependencyProperty.RegisterAttached("Flag", typeof(bool), typeof(TestClass), new PropertyMetadata(false));
public static IValueConverter Converter => new GetFlagConverter();
public class GetFlagConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
var dobj = value as DependencyObject;
if (dobj == null)
{
return false;
}
return GetFlag(dobj);
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
}
}
、私は "STYLE1" のコードを試してみました。しかし、 "Column.local：TestClass.Flag"にはエラーがあります。
私は "style2"コードを試しました。エラーはありません。
ただし、フォントの色は変更されませんでした。
DataTriggerを手動で更新するにはどうすればよいですか？
同じシナリオをシミュレートするために、可能な限り少ないコードを投稿してください。それはあなたに速い答えを与え、また読みやすくなります。 – MYGz