如何在 C# 代码中构建 DataTemplate？

Question

我正在尝试为 winform 互操作构建下拉列表，并且正在代码中创建下拉列表。但是，我无法根据我指定的 DataTemplate 获取要绑定的数据。

我错过了什么？

drpCreditCardNumberWpf = new ComboBox();  
DataTemplate cardLayout = new DataTemplate {DataType = typeof (CreditCardPayment)};   
StackPanel sp = new StackPanel
{
    Orientation = System.Windows.Controls.Orientation.Vertical
};   

TextBlock cardHolder = new TextBlock {ToolTip = "Card Holder Name"};
cardHolder.SetBinding(TextBlock.TextProperty, "BillToName");
sp.Children.Add(cardHolder);

TextBlock cardNumber = new TextBlock {ToolTip = "Credit Card Number"};
cardNumber.SetBinding(TextBlock.TextProperty, "SafeNumber");
sp.Children.Add(cardNumber);

TextBlock notes = new TextBlock {ToolTip = "Notes"};
notes.SetBinding(TextBlock.TextProperty, "Notes");
sp.Children.Add(notes);

cardLayout.Resources.Add(sp, null);

drpCreditCardNumberWpf.ItemTemplate = cardLayout;

Answer 1

假设您已经为drpCreditCardNumberWpf 设置了ItemsSource 等...

//create the data template
DataTemplate cardLayout = new DataTemplate();
cardLayout.DataType = typeof(CreditCardPayment);

//set up the stack panel
FrameworkElementFactory spFactory = new FrameworkElementFactory(typeof(StackPanel));
spFactory.Name = "myComboFactory";
spFactory.SetValue(StackPanel.OrientationProperty, Orientation.Horizontal);

//set up the card holder textblock
FrameworkElementFactory cardHolder = new FrameworkElementFactory(typeof(TextBlock));
cardHolder.SetBinding(TextBlock.TextProperty, new Binding("BillToName"));
cardHolder.SetValue(TextBlock.ToolTipProperty, "Card Holder Name");
spFactory.AppendChild(cardHolder);

//set up the card number textblock
FrameworkElementFactory cardNumber = new FrameworkElementFactory(typeof(TextBlock));
cardNumber.SetBinding(TextBlock.TextProperty, new Binding("SafeNumber"));
cardNumber.SetValue(TextBlock.ToolTipProperty, "Credit Card Number");
spFactory.AppendChild(cardNumber);

//set up the notes textblock
FrameworkElementFactory notes = new FrameworkElementFactory(typeof(TextBlock));
notes.SetBinding(TextBlock.TextProperty, new Binding("Notes"));
notes.SetValue(TextBlock.ToolTipProperty, "Notes");
spFactory.AppendChild(notes);

//set the visual tree of the data template
cardLayout.VisualTree = spFactory;

//set the item template to be our shiny new data template
drpCreditCardNumberWpf.ItemTemplate = cardLayout;

您可以使用与我在TextBlocks 上设置ToolTip 相同的方式来设置其他属性，例如边距。

Answer 2

完整版

var ms = new MemoryStream(Encoding.UTF8.GetBytes(@"<DataTemplate xmlns=""http://schemas.microsoft.com/winfx/2006/xaml/presentation""
                                                                 xmlns:x=""http://schemas.microsoft.com/winfx/2006/xaml""                                                                             
                                                                 xmlns:c=""clr-namespace:MyApp.Converters;assembly=MyApp"">
        <DataTemplate.Resources>
            <c:MyConverter x:Key=""MyConverter""/>
        </DataTemplate.Resources>
        <TextBlock Text=""{Binding ., Converter={StaticResource MyConverter}}""/>
      </DataTemplate>"));
var template = (DataTemplate)XamlReader.Load(ms);

var cb = new ComboBox { };
//Set the data template
cb.ItemTemplate = template;

Answer 3

嗯，其实我们还有其他办法，如果你不喜欢那些FrameworkElementFactory的东西，你会很喜欢的。

而且我认为它只是对自然代码进行了微小的更改，即声明一个 UserControl 并将您的控制权放入其中，然后只使用一个 FrameworkElementFactory 拨打UserControl。

简单的演示代码（F#）：

let buildView()=StackPanel()
//Build it with natural code
type MyView()=inherit UserControl(Content=buildView())
let factory=FrameworkElementFactory(typeof<MyView>)
let template=DataTemplate(VisualTree=factory)
let list=ItemsControl(ItemsSource=makeData(),ItemTemplate=template)