WPF后台创建DataTemplate

在 WPF 编程中，我们通常都是在前台 XAML 中通过标记语言来编写 DataTemplate 的。曾今有小伙伴在 Stack Overflow 上提问，如何在后台通过 C# 代码来创建 DataTemplate ？我搜索了一番，找到了 FrameworkElementFactory 类，它便是生成 DataTemplate 的核心功臣。
先看一下 XAML 中实现的效果

<Grid x:Name="RootGrid">
    <DataGrid x:Name="MyDataGrid" AutoGenerateColumns="False">
        <DataGrid.Columns>
            <DataGridTemplateColumn>
                <DataGridTemplateColumn.CellTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Horizontal">
                            <TextBlock Foreground="Red" Text="{Binding ValueA}"/>
                            <TextBlock Foreground="Blue" Text="{Binding ValueB}" />
                        </StackPanel>
                    </DataTemplate>
                </DataGridTemplateColumn.CellTemplate>
            </DataGridTemplateColumn>
        </DataGrid.Columns>
    </DataGrid>
</Grid>

将 XAML 中的效果用 C# 来实现：

public MainWindow()
{
    InitializeComponent();
    InitializeDataGrid();
}
private void InitializeDataGrid()
{
    // StackPanel and Children
    var stackPanelFactory = new FrameworkElementFactory(typeof(StackPanel));
    stackPanelFactory.SetValue(StackPanel.OrientationProperty, Orientation.Horizontal);
    var textBlockFactoryA = new FrameworkElementFactory(typeof(TextBlock));
    textBlockFactoryA.SetValue(TextElement.ForegroundProperty, Brushes.Red);
    textBlockFactoryA.SetBinding(TextBlock.TextProperty, new Binding("ValueA"));
    var textBlockFactoryB = new FrameworkElementFactory(typeof(TextBlock));
    textBlockFactoryB.SetValue(TextElement.ForegroundProperty, Brushes.Blue);
    textBlockFactoryB.SetBinding(TextBlock.TextProperty, new Binding("ValueB"));
    stackPanelFactory.AppendChild(textBlockFactoryA);
    stackPanelFactory.AppendChild(textBlockFactoryB);
    // DataTemplate
    var dataTemplate = new DataTemplate
    {
        VisualTree = stackPanelFactory
    };
    // DataGridTemplateColumn
    var templateColumn = new DataGridTemplateColumn
    {
        CellTemplate = dataTemplate
    };
    _dataGrid.Columns.Add(templateColumn);
    // DataGrid
    _dataGrid.Name = "MyDataGrid";
    _dataGrid.AutoGenerateColumns = false;
    // Add the DataGrid into RootGrid
    RootGrid.Children.Add(_dataGrid);
}
private readonly DataGrid _dataGrid = new DataGrid();

方法1

DataTemplate template = new DataTemplate();
FrameworkElementFactory factory = new FrameworkElementFactory(typeof(StackPanel));
template.VisualTree = factory;
FrameworkElementFactory childFactory = new FrameworkElementFactory(typeof(Image));
childFactory.SetBinding(Image.SourceProperty, new Binding("Machine.Thumbnail"));
childFactory.SetValue(Image.WidthProperty, 170.0 ) ;
childFactory.SetValue(Image.HeightProperty, 170.0 ) ;
factory.AppendChild(childFactory);
childFactory = new FrameworkElementFactory(typeof(Label));
childFactory.SetBinding(Label.ContentProperty, new Binding("Machine.Descriiption"));
childFactory.SetValue(Label.WidthProperty, 170.0);
childFactory.SetValue(Label.HorizontalAlignmentProperty, HorizontalAlignment.Center);
factory.AppendChild(childFactory);

DataTemplate template = new DataTemplate();

FrameworkElementFactory factory = new FrameworkElementFactory(typeof(StackPanel));

template.VisualTree = factory;

FrameworkElementFactory childFactory = new FrameworkElementFactory(typeof(Image));

childFactory.SetBinding(Image.SourceProperty, new Binding(“Machine.Thumbnail”));

childFactory.SetValue(Image.WidthProperty, 170.0 ) ;

childFactory.SetValue(Image.HeightProperty, 170.0 ) ;

factory.AppendChild(childFactory);

childFactory = new FrameworkElementFactory(typeof(Label));

childFactory.SetBinding(Label.ContentProperty, new Binding(“Machine.Descriiption”));

childFactory.SetValue(Label.WidthProperty, 170.0);

childFactory.SetValue(Label.HorizontalAlignmentProperty, HorizontalAlignment.Center);

factory.AppendChild(childFactory);
方法二
C#
MemoryStream sr = null;

ParserContext pc = null;

string xaml = string.Empty;

xaml = ““;

sr = new MemoryStream(Encoding.ASCII.GetBytes(xaml));

pc = new ParserContext();

pc.XmlnsDictionary.Add(“”, “http://schemas.microsoft.com/winfx/2006/xaml/presentation“);

pc.XmlnsDictionary.Add(“x”, “http://schemas.microsoft.com/winfx/2006/xaml“);

DataTemplate datatemplate = (DataTemplate)XamlReader.Load(sr, pc);

this.Resources.Add(“dt”, datatemplate);