我刚刚遇到了 WPF 的另一个问题。
我有一组自定义控件（复合控件；由网格内的边框等组成）。
我Background通过触发器和绑定来控制它们的颜色。我希望它们在鼠标悬停时变得更暗（通过触发器和自定义实现IValueConverter），但也希望在选择时改变颜色（即单击）。后者是由一个常规的Setter.
<Grid Width="150" Height="50" Margin="5">
<Border CornerRadius="3" BorderBrush="Black" BorderThickness="0.5" >
<Border.Resources>
<local:BackgroundConverter x:Key="ColorConverter"/>
</Border.Resources>
<Border.Style>
<Style TargetType="Border">
<Style.Triggers>
<Trigger Property="Grid.IsMouseOver" Value="True">
<Setter Property="Background" Value="{Binding Path=MyStatus, Converter={StaticResource ColorConverter}}"/>
</Trigger>
<Trigger Property="Grid.IsMouseOver" Value="False">
<Setter Property="Background" Value="{Binding Path=MyStatus, Converter={StaticResource ColorConverter}}"/>
</Trigger>
</Style.Triggers>
<Setter Property="Background" Value="{Binding Path=MyStatus, Converter={StaticResource ColorConverter}}"/>
</Style>
</Border.Style>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="0.6*"/>
<RowDefinition Height="0.5*"/>
</Grid.RowDefinitions>
<TextBlock Grid.Row="0" FontSize="14" TextAlignment="Center" VerticalAlignment="Center" FontWeight="Bold">
<Label Foreground="{Binding Path=TextColor}" Content="{Binding Path=ID}"/>
</TextBlock>
<TextBlock Grid.Row="1" FontSize="9" TextAlignment="Center" VerticalAlignment="Top" Margin="0" Padding="0">
<Label Content="{Binding Path=StockName}"/>
</TextBlock>
</Grid>
</Border>
</Grid>
鼠标悬停效果正常工作，直到我单击其中一个控件。触发器在该点停止工作（除了尚未单击的控件）。
我有点困惑。如何在不禁用触发器的情况下使用绑定？
如有必要，我将提供更多详细信息。
@雷切尔
您可以稍后发布您的转换器代码吗？我看不到 IsMouseOver 属性是如何传递给转换器的，因此它可能是一个静态值，在更改时不会更新。而且由于该值在触发时不会改变，因此它可能不会费心重新评估该值。您最好使用 IMutliValueConverter 并将其传递给 IsMouseOver 和 MyStatus，因此只要这两个值中的任何一个发生变化，它就会重新评估
我没有使用IMultiValueConverter. 为此，我创建了自己的“复合”对象，其中包括IsMouseOver. 这是必要的，因为背景颜色应该是根据我自己的数据（无论是选择项目还是映射项目）以及鼠标悬停（无论背景颜色如何，鼠标悬停时都应该稍微变暗）计算出来的.
转换器代码：
public class BackgroundConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
Debug.WriteLine("BackgroundConverter.Convert()");
if (!(value is StockViewBackgroundStatus))
{
throw new ArgumentException("value");
}
var casted = (StockViewBackgroundStatus)value;
if (casted.IsNone)
{
if (casted.IsMouseOver)
{
return new SolidColorBrush(Colors.Gray);
}
else
{
return CreateLinearGradient(Colors.Gray, false);
}
}
switch (casted.Status)
{
case StockItem.Status.Mapped:
{
return CreateLinearGradient(Color.FromRgb(83, 165, 18), casted.IsMouseOver);
}
case StockItem.Status.MappedElsewhere:
{
return CreateLinearGradient(Color.FromRgb(104, 189, 36), casted.IsMouseOver);
}
case StockItem.Status.NotMapped:
{
return CreateLinearGradient(Colors.LightGray, casted.IsMouseOver);
}
default:
{
throw new NotImplementedException(casted.Status.ToString());
}
}
}
private static LinearGradientBrush CreateLinearGradient(Color initial, bool darker)
{
var darkened = darker ? 0.1 : 0;
return new LinearGradientBrush(
Lighten(initial, 1.05 - darkened),
Lighten(initial, 0.95 - darkened),
90);
}
private static Color Lighten(Color initial, double factor)
{
Func<double, double> trunc = (value) => (Math.Max(0, Math.Min(255, value)));
var resulting = Color.FromRgb(
System.Convert.ToByte(trunc(initial.R * factor)),
System.Convert.ToByte(trunc(initial.G * factor)),
System.Convert.ToByte(trunc(initial.B * factor)));
return resulting;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
Debug.WriteLine("BackgroundConverter.ConvertBack()");
return value;
}
}
StockItem目的
public partial class StockItem : UserControl, INotifyPropertyChanged
{
private bool _empty;
public StockItem()
{
InitializeComponent();
DataContext = this;
}
private string _id;
public string ID
{
get
{
return _id;
}
set
{
_id = value;
RaisePropertyChanged("ID");
}
}
public Brush TextColor
{
get
{
Color color = IsSelected ? Colors.White : Colors.Black;
return new SolidColorBrush(color);
}
}
private string _stockName;
public string StockName
{
get
{
return _stockName;
}
set
{
_stockName = value;
RaisePropertyChanged("StockName");
}
}
StockViewBackgroundStatus _status;
public StockViewBackgroundStatus MyStatus
{
get
{
return new StockViewBackgroundStatus()
{
IsMouseOver = this.IsMouseOver,
IsNone = IsEmpty,
Status = MappingStatus
};
}
set
{
_status = value;
Debug.WriteLine("in " + ID + "...");
Debug.WriteLine("RaisePropertyChanged(\"IsMouseOver\")");
Debug.WriteLine("RaisePropertyChanged(\"MyStatus\")");
RaisePropertyChanged("IsMouseOver"); // added, but doesn't help
RaisePropertyChanged("MyStatus");
}
}
public bool IsEmpty
{
get
{
return _empty;
}
}
public static StockItem EmptyStock
{
get
{
return new StockItem()
{
_empty = true,
ID = "none",
Name = String.Empty
};
}
}
internal EventHandler Selected
{
get;
set;
}
private Status _mappingStatus;
public Status MappingStatus
{
get
{
return _mappingStatus;
}
set
{
_mappingStatus = value;
Debug.WriteLine("in " + ID + "...");
Debug.WriteLine("RaisePropertyChanged(\"MappingStatus\")");
Debug.WriteLine("RaisePropertyChanged(\"TextColor\")");
RaisePropertyChanged("MappingStatus");
RaisePropertyChanged("TextColor");
MyStatus = new StockViewBackgroundStatus() { IsMouseOver = this.IsMouseOver, IsNone = _empty, Status = value };
if (value == Status.Mapped && Selected != null)
{
Selected(this, null);
}
}
}
public bool IsSelected
{
get
{
return MappingStatus == Status.Mapped;
}
}
public enum Status
{
Mapped,
MappedElsewhere,
NotMapped
}
protected void RaisePropertyChanged(string property)
{
if (PropertyChanged == null)
{
return;
}
PropertyChanged(this, new PropertyChangedEventArgs(property));
}
public event PropertyChangedEventHandler PropertyChanged;
}
封装集合的视图类（我实际设置为的视图类DataContext）
public class TargetStocks
{
public ObservableCollection<StockItem> AllStocks
{
get;
set;
}
public void Add(StockItem sv, EventHandler selected)
{
if (sv == null)
{
throw new ArgumentNullException("sv");
}
sv.MouseDown += sv_MouseDown;
if (selected != null)
{
sv.Selected += selected;
}
if (AllStocks == null)
{
AllStocks = new ObservableCollection<StockItem>();
}
AllStocks.Add(sv);
}
public void AddRange(IEnumerable<StockItem> stocks, EventHandler selected)
{
foreach (var stock in stocks)
{
Add(stock, selected);
}
}
void sv_MouseDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
if (!(sender is StockItem))
{
return;
}
var sv = (StockItem)sender;
foreach (StockItem stock in AllStocks)
{
if (stock.MappingStatus == StockItem.Status.Mapped)
{
// this seems to kill the trigger
stock.MappingStatus = StockItem.Status.NotMapped;
}
if (stock == sv && sv.MappingStatus != StockItem.Status.Mapped)
{
// as above
stock.MappingStatus = StockItem.Status.Mapped;
}
}
}
}
如调试所示，发生的情况是在单击任何库存项目之前（或在MappingStatus更改任何库存项目之前），鼠标悬停效果在根本不触发转换器的情况下起作用。
Convert根本没有被调用。
它在似乎禁用（或分离）触发器MappingStatus的事件处理程序中设置。MouseDown