背后帶有代碼的DataTemplate

Question

我正在嘗試在代碼隱藏區中加載DataTemplate，但是如果我刪除Converter，它可以正常工作……但是，一旦將其放入其中，它就會崩潰。 現在，我確實將狀態設置為名稱空間，並在XAML中放置了對轉換器的引用。 例如：

<Window.Resources>
     <local:StatCellConverter x:Key="myConverter" />
</Window.Resources>

這是我生成DataTemplate的方法：

private DataTemplate GenerateStatRowDataTemplate()
{
    ParserContext 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");
    pc.XmlnsDictionary.Add("xcdg", "http://schemas.xceed.com/wpf/xaml/datagrid");

    string statRowTemplate = "<DataTemplate><xcdg:StatRow>";
    statRowTemplate += "<xcdg:StatCell FieldName=\"Column4\" ResultPropertyName=\"AvgColumn4\">";
    statRowTemplate += "<xcdg:StatCell.ContentTemplate>";
    statRowTemplate += "<DataTemplate>";
    statRowTemplate += "<TextBlock Text=\"{Binding ., Converter={StaticResource ResourceKey=myConverter}}\" />";
    statRowTemplate += "</DataTemplate>";
    statRowTemplate += "</xcdg:StatCell.ContentTemplate>";
    statRowTemplate += "</xcdg:StatCell>";
    statRowTemplate += "</xcdg:StatRow>";
    statRowTemplate += "</DataTemplate>";

    StringReader stringReader = new StringReader(statRowTemplate);
    XmlReader xmlReader = XmlReader.Create(stringReader);
    MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(statRowTemplate.ToString()));
    DataTemplate dt = (DataTemplate)XamlReader.Load(ms,pc);
    dt.LoadContent();
    return dt;
}

我究竟做錯了什么？ 難道我也必須在后面的代碼中定義轉換器嗎？

我的轉換器

public class StatCellConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            Debug.WriteLine(value);

            if (value.Equals("#DIV/0#"))
                return "0";
            return value;
        }
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }

我得到一個異常，說它無法加載DataTemplate

Answer 1

實際上，這是框架中的錯誤。 通過XmlnsDictionary添加本地名稱空間將不起作用。 必須使用定義的程序集和名稱空間將其添加到模板定義中：

就像@Nerd In Training的評論一樣，它應該可以工作：

string statRowTemplate = "<DataTemplate >"; 

private DataTemplate GenerateStatRowDataTemplate()
{
    ParserContext 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");
    pc.XmlnsDictionary.Add("xcdg", "http://schemas.xceed.com/wpf/xaml/datagrid");

    string statRowTemplate = "<DataTemplate xmlns:local=\"clr-namespace:MyTest;assembly=MyTest\" ><xcdg:StatRow>";
    statRowTemplate += "<xcdg:StatCell FieldName=\"Column4\" ResultPropertyName=\"AvgColumn4\">";
    statRowTemplate += "<xcdg:StatCell.ContentTemplate>";
    statRowTemplate += "<DataTemplate>";
    statRowTemplate += "<TextBlock Text=\"{Binding ., Converter={StaticResource ResourceKey=myConverter}}\" />";
    statRowTemplate += "</DataTemplate>";
    statRowTemplate += "</xcdg:StatCell.ContentTemplate>";
    statRowTemplate += "</xcdg:StatCell>";
    statRowTemplate += "</xcdg:StatRow>";
    statRowTemplate += "</DataTemplate>";

    StringReader stringReader = new StringReader(statRowTemplate);
    XmlReader xmlReader = XmlReader.Create(stringReader);
    MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(statRowTemplate.ToString()));
    DataTemplate dt = (DataTemplate)XamlReader.Load(ms,pc);
    dt.LoadContent();
    return dt;
}

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;