绑定到UserControl"无法分配给属性"错误(Windows 8)

Question

我正在VS2012中制作一个Windows 8应用程序并尝试将对象(卡)列表绑定到将显示两个字符串的用户控件.这是我在一个页面上的用户控件代码:

<FlipView x:Name="cardView"/>
   <FlipView.ItemTemplate>
      <DataTemplate>
         <local:TileControl x:Name="cardTile" Width="600" Height="400" QuestionText="{Binding Value.question}" AnswerText="{Binding Value.answer}"/>
      </DataTemplate>
   </FlipView.ItemTemplate>
</FlipView>

这是在C#代码后面设置的:

cardView.ItemsSource = Storage.content.Decks[currentDeck].Cards;

用户控件'TileControl'控件中包含以下变量:

public string questionTextStr { get; set; }   
public string answerTextStr { get; set; }

public string QuestionText
{
    get
    {
        return questionTextStr;
    }
    set
    {
        questionTextStr = value;
        questionText.Text = value; //set the textbox content
    }
}

public string AnswerText
{
    get
    {
        return answerTextStr;
    }
    set
    {
        answerTextStr = value;
        answerText.Text = value; //set the textbox content
    }
}

错误列表中的错误说"无法分配给属性'Flashdeck.TileControl.AnswerText'".它也适用于QuestionText.该应用程序将编译并运行,但当我打开包含用户控件的页面时崩溃.我犯错误和崩溃的错误是什么？谢谢.

编辑:甲板和卡类的更多信息.甲板:

public class Deck
    {
        public List<Card> Cards { get; set; }
        public bool flagged { get; set; }

        public Deck()
        {
        }

        public Deck(List<Card> iCards)
        {
            Cards = iCards;
            flagged = false;
        }

        public Deck(List<Card> iCards, bool iFlag)
        {
            Cards = iCards;
            flagged = iFlag;
        }
    }

卡:

public class Card
    {
        public string question { get; set; }
        public string answer { get; set; }
        public bool flagged { get; set; }

        public Card()
        {
        }

        public Card(string iQ, string iA)
        {
            question = iQ;
            answer = iA;
            flagged = false;
        }
    }

Answer 1

您的属性必须是DependencyProperties才能将值绑定到它:

public string QuestionText
{
    get
    {
        return (string)GetValue(QuestionTextProperty);
    }
    set
    {
        SetValue(QuestionTextProperty, value);
        questionText.Text = value; //set the textbox content
    }
}
public static DependencyProperty QuestionTextProperty = DependencyProperty.Register("QuestionText", typeof(string), typeof(Deck), new PropertyMetadata(""));

...

为此,您的类Deck必须继承自DependencyObject.

编辑:在您的Card-Class中没有被称为Value的属性,这就是为什么绑定到Value.question不会工作,请尝试改为

<FlipView x:Name="cardView"/>
   <FlipView.ItemTemplate>
      <DataTemplate>
         <local:TileControl x:Name="cardTile" Width="600" Height="400" QuestionText="{Binding Path=question}" AnswerText="{Binding Path=answer}"/>
      </DataTemplate>
   </FlipView.ItemTemplate>
</FlipView>

并在此处所述的问题/答案属性的setter中调用PropertyChanged事件,以便在属性更改的值时更新绑定.