ScaleTransform 绑定但在绑定 属性 更改时不更新

ScaleTransform binds but does not update when the bound property is changed

我将 ViewScale 绑定到 GridScaleTransform 并且当应用程序启动时它正确缩放 2。但是当我通过按 [=24 更改 ViewScale =]F12,即使属性值改变,也不会触发ScaleTransform更新。

代码如下:

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
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.Navigation;
using System.Windows.Shapes;

namespace test
{
    public partial class MainWindow : Window
    {
        public event PropertyChangedEventHandler PropertyChanged;
        protected void SetField<T> ( ref T field, T value, string propertyName )
        {
            if ( !EqualityComparer<T>.Default.Equals ( field, value ) )
            {
                field = value;
                PropertyChanged?.Invoke ( this, new PropertyChangedEventArgs ( propertyName ) );
            }
        }


        decimal viewScale = 2;
        public decimal ViewScale
        {
            get => this.viewScale;
            set => SetField ( ref this.viewScale, value,
                "ViewScale"
                );
        }

        ObservableCollection<Coin> _coins;
        public ObservableCollection<Coin> Coins { get => _coins; set => SetField ( ref _coins, value, nameof ( _coins ) ); }
        public ICollectionView CollectionView;

        public MainWindow ( )
        {
            this.Coins = new ObservableCollection<Coin> ( );
            for ( int i = 0 ; i < 100 ; ++i )
                this.Coins.Add ( new Coin ( "Coin 1", i ) );

            this.DataContext = this;

            InitializeComponent ( );

            this.PreviewKeyDown += MainWindow_PreviewKeyDown;
        }

        void MainWindow_PreviewKeyDown ( object sender, KeyEventArgs e )
        {
            Console.WriteLine ( e.Key );
            if ( e.Key == Key.Home )
            {
                this.dataGrid.ScrollIntoView ( this.dataGrid.Items [ this.dataGrid.Items.Count - 1 ] );
                this.dataGrid.UpdateLayout ( );
                this.dataGrid.ScrollIntoView ( this.dataGrid.Items [ 0 ] );
            }
            else if ( e.Key == Key.F12 )
            {
                this.ViewScale += 0.1m;
            }
        }

        void MainWindow_KeyDown ( object sender, KeyEventArgs e )
        {

        }
    }

    public class Coin
    {
        public string Symbol { get; set; }
        public int PNL { get; set; }
        public SolidColorBrush Color2 { get; set; }

        public Coin ( string symbol, int pnl )
        {
            this.Symbol = symbol;
            this.PNL = pnl;

            Random rnd = new Random ( );
            Color c = Color.FromRgb ( ( byte ) rnd.Next ( 256 ), ( byte ) rnd.Next ( 256 ), ( byte ) rnd.Next ( 256 ) );

            this.Color2 = new SolidColorBrush ( c );
        }
    }
}

XAML:

<Window x:Class="test.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:test"
    mc:Ignorable="d"
    Name="myMainWindow"
    SizeToContent="Width"
    DataContext="{Binding RelativeSource={RelativeSource Self}}"
    Title="Profit Tracker"
    WindowStyle="None"
    Topmost="True"
    Height="426">

    <Window.Resources>

        <Style x:Key="DataGridColumnSeparatorStyle" TargetType="DataGridCell">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate>
                        <Rectangle VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Fill="#1e90ff"/>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

        <Style x:Key="DataGridColumnAlarmStyle" TargetType="DataGridCell">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate>
                        <Rectangle VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Fill="#000000"/>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>



        <Style TargetType="{x:Type DataGrid}">
            <Setter Property="Background" Value="#FFF" />
            <Setter Property="AlternationCount" Value="2" />
            <Setter Property="BorderBrush" Value="Red" />
            <Setter Property="BorderThickness" Value="0" />
        </Style>

        <Style x:Key="RowStyleWithAlternation" TargetType="DataGridRow">
            <Setter Property="Background" Value="#141414"/>
            <Setter Property="Foreground" Value="White"/>
            <Setter Property="FontWeight" Value="Normal"/>
            <Style.Triggers>
                <Trigger Property="AlternationIndex" Value="0">
                    <Setter Property="Background" Value="#141414"/>
                </Trigger>
                <Trigger Property="AlternationIndex" Value="1">
                    <Setter Property="Background" Value="#282828"/>
                </Trigger>
                <Trigger Property="IsSelected" Value="True">
                    <Setter Property="BorderBrush" Value="Red" />
                    <Setter Property="BorderThickness" Value="1" />
                    <Setter Property="Margin" Value="-1,0,0,0" />
                </Trigger>
                <Trigger Property="IsMouseOver" Value="True">
                    <!--<Setter Property="BorderBrush" Value="#2eff00" />
                    <Setter Property="BorderThickness" Value="1" />-->
                    <Setter Property="Background" Value="Orange"/>
                    <!--<Setter Property="Margin" Value="-1,0,0,0" />-->
                </Trigger>
            </Style.Triggers>
        </Style>

        <Style TargetType="DataGridCell">
            <Setter Property="TextBlock.TextAlignment" Value="Center" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type DataGridCell}">
                        <Grid Background="{TemplateBinding Background}">
                            <ContentPresenter VerticalAlignment="Stretch"/>
                        </Grid>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
            <Setter Property="VerticalAlignment" Value="Stretch"/>
            <Setter Property="Padding" Value="0"/>
            <Setter Property="Margin" Value="0"/>
            <Setter Property="BorderThickness" Value="0"/>
            <Setter Property="FocusVisualStyle" Value="{x:Null}" />

            <Style.Triggers>
                <Trigger Property="IsSelected" Value="True">
                    <Setter Property="BorderBrush" Value="#1e90ff" />
                    <Setter Property="BorderThickness" Value="1" />
                    <!--<Setter Property="Background" Value="Red"/>-->
                </Trigger>



                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding Column.DisplayIndex, RelativeSource={RelativeSource Self}}" Value="4"/>
                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.Setters>
                        <Setter Property="VerticalAlignment" Value="Stretch"/>
                    </MultiDataTrigger.Setters>
                </MultiDataTrigger>

                <Trigger Property="IsSelected" Value="True">
                    <Setter Property="Background" Value="{x:Null}"/>
                    <Setter Property="BorderBrush" Value="{x:Null}"/>
                </Trigger>
            </Style.Triggers>
        </Style>

        <Style TargetType="DataGridColumnHeader">
            <Setter Property="HorizontalContentAlignment" Value="Center" />
        </Style>

        <Style TargetType="{x:Type ProgressBar}">
            <Setter Property="Padding" Value="0"/>
            <Setter Property="Margin" Value="0"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="ProgressBar">
                        <Border BorderThickness="1" Background="#006400" CornerRadius="0" Padding="0">
                            <Grid x:Name="PART_Track">
                                <Rectangle x:Name="PART_Indicator" HorizontalAlignment="Left" Fill="#75001D" />
                            </Grid>
                        </Border>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

        <CollectionViewSource Source="{Binding Coins}" IsLiveSortingRequested="True" x:Key="MyKey" />

    </Window.Resources>

    <Grid>

        <Grid.LayoutTransform>
            <ScaleTransform ScaleX="{Binding ViewScale, ElementName=myMainWindow}" ScaleY="{Binding ViewScale, ElementName=myMainWindow}" />
        </Grid.LayoutTransform>

        <DataGrid Name="dataGrid" ItemsSource="{Binding Source={StaticResource MyKey}}" SelectionMode="Single" GridLinesVisibility="None" HorizontalScrollBarVisibility="Hidden" RowHeaderWidth="0" IsReadOnly="True" CanUserAddRows="False" CanUserResizeColumns="False" CanUserResizeRows="False" AutoGenerateColumns="False" RowStyle="{StaticResource RowStyleWithAlternation}">
            <DataGrid.Resources>
                <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="Transparent" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="Transparent" />
            </DataGrid.Resources>

            <DataGrid.Columns>

                <DataGridTemplateColumn MinWidth="0" Width="2" CellStyle="{StaticResource DataGridColumnSeparatorStyle}"/>
                <DataGridTextColumn Header="PNL" Width="60" SortMemberPath="Balance.UnitPrice" Binding="{Binding Path=PNL}" />

                <DataGridTemplateColumn MinWidth="0" Width="2" CellStyle="{StaticResource DataGridColumnSeparatorStyle}" CanUserSort="False"/>

                <DataGridTemplateColumn Header="Price" Width="60" SortMemberPath="Price">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <Grid>
                                <Grid>
                                    <Border BorderBrush="#241C59" BorderThickness="1" CornerRadius="1" Background="#2D255B">
                                        <Border BorderBrush="#206fb6" BorderThickness="4" CornerRadius="2" ClipToBounds="True" Margin="-1" HorizontalAlignment="Stretch">
                                            <Border.Effect>
                                                <BlurEffect Radius="10"/>
                                            </Border.Effect>
                                        </Border>
                                    </Border>
                                    <Border Margin="1" VerticalAlignment="Stretch" BorderThickness="0." Background="#69ABDB" HorizontalAlignment="Left" Width="30">
                                        <Border BorderBrush="#38e2ff" BorderThickness="2" CornerRadius="2" ClipToBounds="False">
                                            <Border.Effect>
                                                <BlurEffect Radius="5"/>
                                            </Border.Effect>
                                        </Border>
                                    </Border>
                                </Grid>
                                <TextBlock Text="25%" HorizontalAlignment="Center" VerticalAlignment="Center"/>
                            </Grid>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>

                <DataGridTemplateColumn Header="Vol BTC/h" Width="30" SortMemberPath="LastHourVolumeInBtc">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <Grid>
                                <TextBlock Text="ABCDE" HorizontalAlignment="Center" VerticalAlignment="Center"/>
                            </Grid>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>

                <DataGridTemplateColumn Header="Vol BTC/h" Width="40">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <Grid>
                                <ProgressBar Value="0.3" Minimum="0" Maximum="1"/>
                                <TextBlock Text="12345" HorizontalAlignment="Center" VerticalAlignment="Center"/>
                            </Grid>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>

                <DataGridTextColumn Header="Net BTC/m" Width="60"/>
            </DataGrid.Columns>
        </DataGrid>
    </Grid>
</Window>

为了提供 属性 更改通知,您必须 implement the INotifyPropertyChanged interface 在定义绑定 属性 的类型中。您在 MainWindow 代码隐藏中错过了这部分,这也是您 window.

的数据上下文
public partial class MainWindow : Window, INotifyPropertyChanged

虽然您定义了 PropertyChanged 事件并且您的 SetField 方法正确地引发了该事件,但如果您没有在 class 上声明接口,WPF 将不会意识到它定义。