为什么克隆的UIElement或FrameworkElement的样式丢失
cod*_*der 7 c# wpf xaml clone uielement
我试图加载Grid与UIElementS和/或FrameworkElement该含有S Style和DataTrigger秒。
以下是一个简单的本机XAML，它可以按预期工作；在3个状态之间切换复选框可为矩形提供三种不同的样式（请参见底部的图像）。
<Grid
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:XamlVsLoad"
mc:Ignorable="d"
Height="450" Width="800">
<CheckBox Name="MyCheck" IsChecked="True" Content="Checkbox" IsThreeState="True" Margin="10,10,0,0" Width="200"/>
<Rectangle Height="100" Width="100" StrokeThickness="5" Margin="10,50,100,100">
<Rectangle.Style>
<Style TargetType="Rectangle">
<Setter Property="Fill" Value="White"/>
<Setter Property="Stroke" Value="Black"/>
<Style.Triggers>
<DataTrigger Binding="{Binding ElementName=MyCheck, Path=IsChecked}" Value="True" >
<Setter Property="Fill" Value="Orange"/>
<Setter Property="Stroke" Value="Blue"/>
</DataTrigger>
<DataTrigger Binding="{Binding ElementName=MyCheck, Path=IsChecked}" Value="False" >
<Setter Property="Fill" Value="Blue"/>
<Setter Property="Stroke" Value="Orange"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Rectangle.Style>
</Rectangle>
</Grid>
它也可以当我相同的文本保存到一个文件和动态加载到Window的 Viewbox与XAML这样S：
<Grid.ColumnDefinitions>
<ColumnDefinition Width="100"/>
<ColumnDefinition Width="100"/>
<ColumnDefinition Width="100"/>
<ColumnDefinition Width="100"/>
</Grid.ColumnDefinitions>
<DockPanel Grid.Column="0">
<DockPanel>
<Label Content="Native" DockPanel.Dock="Top" HorizontalAlignment="Center" Margin="10,10,10,10" />
<Viewbox Name="NativeViewbox" Height="auto" Width="200" DockPanel.Dock="Top"/>
<!-- Native Grid Omitted for brevity 3 uniquely named checkboxes -->
</Viewbox>
</DockPanel>
<DockPanel Grid.Column="1">
<DockPanel>
<Label Content="Dynamic" DockPanel.Dock="Top" HorizontalAlignment="Center" Margin="10,10,10,10" />
<Viewbox Name="DynamicViewbox" Height="auto" Width="200" DockPanel.Dock="Top"/>
</DockPanel>
</DockPanel>
<DockPanel Grid.Column="2">
<DockPanel>
<Label Content="Clone" DockPanel.Dock="Top" HorizontalAlignment="Center" Margin="10,10,10,10" />
<Viewbox Name="CloneViewbox" Height="auto" Width="200" DockPanel.Dock="Top" />
</DockPanel>
</DockPanel>
<DockPanel Grid.Column="3">
<DockPanel>
<Label Content="Saved" DockPanel.Dock="Top" HorizontalAlignment="Center" Margin="10,10,10,10" />
<Viewbox Name="SavedViewbox" Height="auto" Width="200" DockPanel.Dock="Top"/>
</DockPanel>
</DockPanel>
但是，如果我尝试将FrameworkElements/ UIElements从一个Grid/容器复制/克隆/深复制（我尝试了几种不同的方法），则该样式不再起作用。以下是我目前加载和克隆它们的各种方法：
public partial class ReadCopy : Window {
public ReadCopy() {
InitializeComponent();
// test the dynamic load
Grid NativeXaml = ReadGrid("C:\\XamlFiles\\LoadXaml.xaml");
DynamicViewbox.Child = NativeXaml; // honors style
// test the Clone load
Grid CloneXaml = new Grid();
foreach (FrameworkElement fe in NativeXaml.Children) CloneXaml.Children.Add(Clone(fe));
CloneViewbox.Child = CloneXaml; // doesn't honor style
// test the save Clone and then load
StringBuilder outstr = new StringBuilder();
XmlWriterSettings settings = new XmlWriterSettings { Indent = true, OmitXmlDeclaration = true, IndentChars = " ", NewLineChars = "\r\n", NewLineHandling = NewLineHandling.Replace };
XamlDesignerSerializationManager dsm = new XamlDesignerSerializationManager(XmlWriter.Create(outstr, settings)) { XamlWriterMode = XamlWriterMode.Expression };
XamlWriter.Save(CloneXaml, dsm);
File.WriteAllText("C:\\XamlFiles\\SavedXaml.xaml", outstr.ToString());
Grid SavedXaml = ReadGrid("C:\\XamlFiles\\SavedXaml.xaml");
SavedViewbox.Child = SavedXaml; // honors style and triggers again...
}
public Grid ReadGrid(string fn) {
FileStream fs = new FileStream(fn, FileMode.Open);
return XamlReader.Load(fs) as Grid;
}
public FrameworkElement Clone(FrameworkElement it) {
FrameworkElement clone;
using (var stream = new MemoryStream()) {
XamlWriter.Save(it, stream);
stream.Seek(0, SeekOrigin.Begin);
clone = (FrameworkElement)XamlReader.Load(stream);
}
clone.Style = it.Style; // setting it or not has no effect
return clone;
}
}
通过XamlWriter.Save开始的简单示例网格的克隆XAML的输出：
<Grid xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<CheckBox IsChecked="True" IsThreeState="True" Style="{x:Null}" Name="MyCheck" Width="200" Margin="10,10,0,0">Checkbox</CheckBox>
<Rectangle StrokeThickness="5" Width="100" Height="100" Margin="10,50,100,100">
<Rectangle.Style>
<Style TargetType="Rectangle">
<Style.Triggers>
<DataTrigger Binding="{Binding Path=IsChecked, ElementName=MyCheck}" Value="True">
<Setter Property="Shape.Fill">
<Setter.Value>
<SolidColorBrush>#FFFFA500</SolidColorBrush>
</Setter.Value>
</Setter>
<Setter Property="Shape.Stroke">
<Setter.Value>
<SolidColorBrush>#FF0000FF</SolidColorBrush>
</Setter.Value>
</Setter>
</DataTrigger>
<DataTrigger Binding="{Binding Path=IsChecked, ElementName=MyCheck}" Value="False">
<Setter Property="Shape.Fill">
<Setter.Value>
<SolidColorBrush>#FF0000FF</SolidColorBrush>
</Setter.Value>
</Setter>
<Setter Property="Shape.Stroke">
<Setter.Value>
<SolidColorBrush>#FFFFA500</SolidColorBrush>
</Setter.Value>
</Setter>
</DataTrigger>
</Style.Triggers>
<Style.Resources>
<ResourceDictionary />
</Style.Resources>
<Setter Property="Shape.Fill">
<Setter.Value>
<SolidColorBrush>#FFFFFFFF</SolidColorBrush>
</Setter.Value>
</Setter>
<Setter Property="Shape.Stroke">
<Setter.Value>
<SolidColorBrush>#FF000000</SolidColorBrush>
</Setter.Value>
</Setter>
</Style>
</Rectangle.Style>
</Rectangle>
</Grid>
虽然我可以看到它重新格式化了Style，但我不明白为什么在设置Viewbox.Child克隆时它不再起作用。更令人困惑的是，加载克隆的已保存文件就可以了。这是全部四个（本机，动态，克隆，已保存的克隆重载）的外观：
谁能解释如何通过复制/克隆正确保留样式？
小智 5
在Style对Rectangle被触发CheckBox。因此，Clone()将无法单独加载子元素。要同时加载它们，请克隆其父级Grid本身。我转载了您的问题，这对我有用：
Grid NativeXaml = ReadGrid();
DynamicViewbox.Child = NativeXaml;
Grid CloneXaml = (Grid)Clone(NativeXaml);
CloneViewbox.Child = CloneXaml;