我有一个ObservableCollection'＆lt;'NextBestAction'＆gt;' NextBestActions称为NextBestActions，其中NextBestAction为：
[TypeConverter(typeof(NextBestActionTypeConverter))]
public class NextBestAction : IDisposable
{
public bool isDismissable, dismissed, completed;
public NextBestActionType type;
public string title, description;
public void Dispose()
{
this.Dispose();
}
public NextBestAction()
{
}
public NextBestAction(string title, string description)
{
this.title = title;
this.description = description;
}
public static NextBestAction Parse(Card card)
{
if (card == null)
{
return new NextBestAction();
}
return new NextBestAction(card.Title.Text, card.Description.Text);
}
}
我也有自己的UserControl名为Card，其中Card是：
public partial class Card : UserControl
{
public Card()
{
InitializeComponent();
this.DataContext = this;
}
public Card(string title, string description)
{
InitializeComponent();
this.DataContext = this;
this.Title.Text = title;
this.Description.Text = description;
}
public static Card Parse(NextBestAction nextBestAction)
{
if (nextBestAction == null)
{
return new Card();
}
return new Card(nextBestAction.title, nextBestAction.description);
}
}
使用后续XAML：
<UserControl x:Class="AdvancedTeller.Card"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:AdvancedTeller"
mc:Ignorable="d"
d:DesignWidth="300" Background="White" BorderBrush="#FF333333" VerticalContentAlignment="Top" Width="400">
<Grid Margin="10" VerticalAlignment="Top">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<TextBlock Name="Title" Grid.Column="1" Grid.Row="0" FontSize="18.667" Margin="3"/>
<TextBlock Name="Description" Grid.Column="1" Grid.Row="1" VerticalAlignment="Top" TextWrapping="Wrap" Margin="3"/>
</Grid>
最后，我已将NextBestAction的TypeConverter定义为
public class NextBestActionTypeConverter : TypeConverter
{
// Override CanConvertFrom to return true for Card-to-NextBestAction conversions.
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
{
if (sourceType == typeof(Card))
{
return true;
}
return base.CanConvertFrom(context, sourceType);
}
// Override CanConvertTo to return true for NextBestAction-to-Card conversions.
public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
{
if (destinationType == typeof(Card))
{
return true;
}
return base.CanConvertTo(context, destinationType);
}
// Override ConvertFrom to convert from a Card to an instance of NextBestAction.
public override object ConvertFrom(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value)
{
Card card = value as Card;
if (card != null)
{
try
{
return NextBestAction.Parse(card);
}
catch (Exception e)
{
throw new Exception(String.Format("Cannot convert '{0}' ({1}) because {2}", value, value.GetType(), e.Message), e);
}
}
return base.ConvertFrom(context, culture, value);
}
// Override ConvertTo to convert from an instance of NextBestAction to Card.
public override object ConvertTo(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destinationType)
{
if (destinationType == null)
{
throw new ArgumentNullException("destinationType");
}
//Convert Complex to a string in a standard format.
NextBestAction nextBestAction = value as NextBestAction;
if (nextBestAction != null && this.CanConvertTo(context, destinationType) && destinationType == typeof(Card))
{
try
{
return Card.Parse(nextBestAction);
}
catch (Exception e)
{
throw new Exception(String.Format("Cannot convert '{0}' ({1}) because {2}", value, value.GetType(), e.Message), e);
}
}
return base.ConvertTo(context, culture, value, destinationType);
}
}
我正在尝试将NextBestActions绑定到StackPanel，并强制NextBestActions在UI中表示为卡片。
到目前为止，我已经明白我至少需要这个
<StackPanel Grid.Column="1" Grid.Row="1" Grid.RowSpan="2" Margin="50" >
<ItemsControl Name="NextBestActionItems" ItemsSource="{Binding NextBestActions}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<AdvancedTeller:Card />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</StackPanel>
代码编译并运行没有任何问题，并且在StackPanel中为ObservableCollection中的每个项创建并显示了一个Card，但是，每个Card的Title和Description都是空白的，不会获取它们各自NextBestAction的数据。
我觉得我90％都在那里。我将不胜感激任何帮助。谢谢！
UPDATE / EDIT 1：目前未调用/命中NextBestActionTypeConverter。如果我从XAML中删除ItemsControl.ItemTemplate定义，则调用NextBestActionTypeConverter，但将destinationType作为“string”。我试图强制/设置ItemsControl以了解itesm将被表示为卡片。
更新/编辑2（答案）：以下是答案的片段：
// Override ConvertTo to convert from an instance of NextBestAction to Card.
public override object ConvertTo(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destinationType)
{
if (destinationType == null)
{
throw new ArgumentNullException("destinationType");
}
//Convert Complex to a string in a standard format.
NextBestAction nextBestAction = value as NextBestAction;
if (nextBestAction != null && this.CanConvertTo(context, destinationType) && destinationType == typeof(Card))
{
try
{
return new Card();
}
catch (Exception e)
{
throw new Exception(String.Format("Cannot convert '{0}' ({1}) because {2}", value, value.GetType(), e.Message), e);
}
}
return base.ConvertTo(context, culture, value, destinationType);
}
和
public partial class Card : UserControl
{
public Card()
{
InitializeComponent();
}
}
和
<UserControl x:Class="AdvancedTeller.Card"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:AdvancedTeller"
mc:Ignorable="d"
d:DesignWidth="300" Background="White" BorderBrush="#FF333333" VerticalContentAlignment="Top" Width="400">
<Grid Margin="10" VerticalAlignment="Top">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<TextBlock Name="Title" Grid.Column="1" Grid.Row="0" FontSize="18.667" Margin="3" Text="{Binding Title}"/>
<TextBlock Name="Description" Grid.Column="1" Grid.Row="1" VerticalAlignment="Top" TextWrapping="Wrap" Margin="3" Text="{Binding Description}"/>
</Grid>
答案 0 :(得分：0)
我可以看到代码中存在一些潜在的问题点。
首先，您的get; set;对象中的Title和Description定义了NextBestAction访问者方法，看起来您没有完整的属性。
如果我没记错的话，WPF的绑定系统需要具有get / set访问器的完整属性，并且不会绑定到没有它们的字段。
所以
public string title, description;
应该成为
public string Title { get; set; }
public string Description { get; set; }
另一个潜在的问题可能是你没有在Card UserControl中绑定标题/描述文本框的.Text属性。
因此，假设您没有使用基于Caliburn Micro等.Name属性自动创建Bindings的框架，此代码
<TextBlock Name="Title" ... />
<TextBlock Name="Description" ... />
应该是
<TextBlock Name="Title" Text="{Binding Title}" ... />
<TextBlock Name="Description" Text="{Binding Description}" ... />
此外，我非常确定绑定区分大小写，因此您需要确保绑定（或Name属性，如果使用Caliburn Micro）的情况与您的属性的情况相符。
最后，每当我看到UserControl硬编码.DataContext时，警告就会消失在我脑海中。 UserControls不应该这样做。他们应该从使用控件的任何代码中获取他们的DataContext，并且不应该创建他们自己的。删除在.DataContext UserControl中对Card进行硬编码的以下代码行，然后它将使用NextBestActions集合中的任何值。
public Card()
{
InitializeComponent();
this.DataContext = this; // Bad!
}
public Card(string title, string description)
{
InitializeComponent();
this.DataContext = this; // Bad!
this.Title.Text = title; // Should be replaced with bindings as above
this.Description.Text = description; // Should be replaced with bindings as above
}
（作为旁注，我不知道你在使用TypeConverter做什么:)它通常用于将一种类型转换为另一种类型，例如将字符串"Red"更改为SolidColorBrush当您输入.Color之类的内容时，<StackPanel Background="Red" />设置为红色。我没有看到你当前的代码使用它，并建议完全摆脱它，除非你出于某些特定原因需要它。）