Question

我正在尝试更改WPF应用程序的样式（FontFamily，FontSize等）。搜索SO失败。在应用程序中，我使用MVVM模式。为了给我的应用程序一个统一的外观，我使用资源字典来定义不同的样式和外观。到目前为止，该方法有效。我要实现的是使用样式窗口按运行时更改单个属性：

    <Window x:Class="StyleResourceDictionariesDemo.View.StyleWindow"
        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"
        mc:Ignorable="d"
        Title="StyleWindow" Height="450" Width="800"
        Style="{DynamicResource WindowStyle}">
    <Window.Resources>
        <ResourceDictionary Source="../ResourceDictionaries/Styles/Controls/WindowStyle.xaml"/>
    </Window.Resources>
    <StackPanel Orientation="Vertical">
        <StackPanel Orientation="Horizontal" HorizontalAlignment="Left">
            <TextBlock Height="20" Width="75" Text="FontFamily:" Margin="10" TextAlignment="Right"/>
            <ComboBox x:Name="CbFonts" Width="200" Margin="10,10,7,0"
                      ItemsSource="{Binding Source={x:Static Fonts.SystemFontFamilies}}" SelectedItem="{Binding OwnFontFamily, UpdateSourceTrigger=PropertyChanged}"
                      SelectedValuePath="Source" Height="23" VerticalAlignment="Top">
                <ComboBox.ItemTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding}" FontFamily="{Binding}" Height="20"/>
                    </DataTemplate>
                </ComboBox.ItemTemplate>
            </ComboBox>
        </StackPanel>
        <Border Height="2" Width="Auto" Background="Red" HorizontalAlignment="Stretch" VerticalAlignment="Center"/>
        <StackPanel Orientation="Horizontal"  HorizontalAlignment="Left">
            <TextBlock Height="20" Width="50" Text="Size:" Margin="10" TextAlignment="Right"/>
            <Slider Style="{DynamicResource SliderStyle}" Width="100" x:Name="FontSizeSlider" Value="{Binding OwnFontSize, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
                    Minimum="{Binding OwnSmallFontSize}" Maximum="{Binding OwnBigFontSize}" TickPlacement="Both" Margin="10" TickFrequency="{Binding OwnFontSizeSteps}" IsSnapToTickEnabled="True"/>
            <TextBlock Height="20" Width="50" Text="{Binding ElementName=FontSizeSlider, Path=Value, UpdateSourceTrigger=PropertyChanged}" TextAlignment="Right"/>
        </StackPanel>
    </StackPanel>
</Window>

附加以下视图模型：

using System.Windows.Media;

namespace StyleResourceDictionariesDemo.ViewModel
{
  class StyleWindowViewModel : ViewModelBase
  {
    #region Variables
    private double _ownFontSize = 12, _ownSmallFontSize = 8, _ownBigFontSize = 16;
    private FontFamily _ownFontFamily = new FontFamily("Arial");
    #endregion

    #region Properties
    public double OwnFontSizeSteps { get; } = 4;
    public FontFamily OwnFontFamily
    {
      get => _ownFontFamily;
      set
      {
        _ownFontFamily = new FontFamily(value.Source);
        OnPropertyChanged(nameof(OwnFontFamily));
      }
    }


    public double OwnFontSize
    {
      get => _ownFontSize;
      set
      {
        _ownFontSize = value;
        OnPropertyChanged(nameof(OwnFontSize));
      }
    }
    public double OwnSmallFontSize
    {
      get => _ownSmallFontSize;
      set
      {
        _ownSmallFontSize = value;
        OnPropertyChanged(nameof(OwnSmallFontSize));
      }
    }
    public double OwnBigFontSize
    {
      get => _ownBigFontSize;
      set
      {
        _ownBigFontSize = value;
        OnPropertyChanged(nameof(OwnBigFontSize));
      }
    }
    #endregion

    #region Constructor
    public StyleWindowViewModel()
    {

    }
    #endregion


  }
}

此外，我还创建了ControlBaseStyle xaml文件，其他所有样式都从该文件继承：

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                   xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                   xmlns:viewModel="clr-namespace:StyleResourceDictionariesDemo.ViewModel">
    <viewModel:StyleWindowViewModel x:Key="StyleWindowViewModel" />
    <Style TargetType="{x:Type Control}" x:Key="ControlBaseStyle">
        <Style.Setters>
            <Setter Property="FontFamily" Value="{DynamicResource OwnFontFamily}"/>
            <Setter Property="FontStyle" Value="{DynamicResource FontStyleKey}"/>
            <Setter Property="FontWeight" Value="{DynamicResource FontWeightKey}"/>
            <Setter Property="FontSize" Value="{DynamicResource OwnFontSize}"/>
            <Setter Property="Background" Value="{DynamicResource SystemBackground}"/>
            <Setter Property="Foreground" Value="{DynamicResource SystemForeground}"/>
        </Style.Setters>
    </Style>
</ResourceDictionary>

我的问题是controlbasestyle无法识别ViewModel属性中的更改，而我目前不知道为什么。也许我错过了一些简单的事情，只是看不到，还是我采取了错误的方法来解决这个问题？

谢谢。

米尔科

编辑1：

我的目标是在运行时更改样式和外观。结构如下：最初，外观为所有样式分配了不同的属性。外观定义了颜色，字体，大小以及应在应用程序中保持一致的其他内容。这些可以通过其特定名称（用x：key定义）来调用。样式使用当前使用的setter的名称来检索在皮肤上方定义的值（例如，属性背景的Value = -DynamicResource SystemBackground-）。到目前为止一切顺利。

目标是使用MVVM模式执行此操作。我已经定义了一个样式窗口和一个ViewModel（上面的代码）。但是我无法让样式注意到变化。

现在的第一个问题是，我可以吗？如果可以，如何在运行时更改FontFamily（或任何其他属性）的值。第二个问题是，这种方法在现实生活中是完全正确的，还是有更好的方法？

示例皮肤：

LightSkin.xaml:
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
    <ResourceDictionary.MergedDictionaries>
        <!--Default Style-->
        <ResourceDictionary Source="../00_Default/DefaultStyle.xaml"/>

        <!--Specific Style-->
        <ResourceDictionary Source="LightColor.xaml"/>
        <ResourceDictionary Source="LightSizes.xaml"/>
        <ResourceDictionary Source="LightFont.xaml"/>
    </ResourceDictionary.MergedDictionaries>
</ResourceDictionary>

DefaultStyle.xaml:
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
<ResourceDictionary.MergedDictionaries>
    <ResourceDictionary Source="../../Styles/Controls/ButtonStyle.xaml"/>
    <ResourceDictionary Source="../../Styles/Controls/LabelStyle.xaml"/>
    <ResourceDictionary Source="../../Styles/Controls/ToggleButtonStyle.xaml"/>
    <ResourceDictionary Source="../../Styles/Controls/WindowStyle.xaml"/>
</ResourceDictionary.MergedDictionaries>

LabelBaseStyle.xaml:
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="ControlBaseStyle.xaml"/>
    </ResourceDictionary.MergedDictionaries>
    <Style TargetType="{x:Type Label}" x:Key="LabelBaseStyle" BasedOn="{StaticResource ControlBaseStyle}">
        <Style.Setters>
            <Setter Property="Width" Value="300"/>
            <Setter Property="Height" Value="150"/>
            <Setter Property="HorizontalAlignment" Value="Center"/>
            <Setter Property="VerticalAlignment" Value="Top"/>
            <Setter Property="Content" Value="{Binding Content}"/>
        </Style.Setters>
    </Style>
</ResourceDictionary>

每个（Base-）Style都直接或间接继承自ControlBaseStyle.xaml（上面的代码）。

Answer 1

您应该将i=0 while i<=4: print "i = ", i j=0 while j<=4: print "j = ", j j = j + 1 i = i + 1的设置器绑定到视图模型的属性：

ControlBaseStyle

还要确保要更改样式时，设置在<viewModel:StyleWindowViewModel x:Key="StyleWindowViewModel" /> <Style TargetType="{x:Type Control}" x:Key="ControlBaseStyle"> <Style.Setters> <Setter Property="FontFamily" Value="{Binding OwnFontFamily, Source={StaticResource StyleWindowViewModel}}"/> ... </Style.Setters> </Style>中定义的实际StyleWindowViewModel实例的属性。

在ResouceDictionary中将样式Propety的值绑定到ViewModel属性

1 个答案: