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我剛剛遇到了WPF的另一個問題。普通的數據綁定似乎禁用觸發器
我有一個自定義控件的集合（複合的;由網格內的邊框等組成）。
我通過觸發器和綁定來控制顏色Background。我希望它們在mouseover（通過觸發器和自定義IValueConverter）實現時變得更暗，而且在選擇（即，單擊）時更改顏色。後者由常規Setter完成。
<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>
鼠標懸停效果工作正常，直到我點擊其中一個控件。觸發器在該點停止工作（除了未被點擊的控件外）。
我有點困惑。我如何在不禁用觸發器的情況下對某些用法進行綁定？
如有必要，我會提供更多細節。
@Rachel
您可以發佈您的代碼轉換器以後？我沒有看到如何將 IsMouseOver屬性傳遞給轉換器，因此它的 可能是一個靜態值，它在更改時未更新。並且由於 該值在觸發時不會改變，因此可能不會打擾 重新評估該值。你可能會更好使用 IMutliValueConverter並將其傳遞IsMouseOver和MyStatus，所以 隨時得到重新評估的任這兩個值改變
我沒有使用IMultiValueConverter。爲此，我創建了自己的「複合」對象，其中包括IsMouseOver。這是必要的，因爲背景顏色應該是在我自己的數據之外計算出來的（無論是選中還是映射項目）以及鼠標懸停（無論背景顏色，它應該在鼠標上略微變暗） 。
轉換代碼：
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對象
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;
}
視圖類封裝集合（在一個我實際上設定爲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;
}
}
}
}
如調試所示，在點擊任何庫存項目之前（或者在任何庫存項目的MappingStatus發生更改之前），鼠標懸停效果將起作用，而不會觸發轉換器。
Convert根本沒有被調用。
它在MouseDown事件處理程序中設置MappingStatus，似乎禁用（或分離）觸發器。
您是否可以編輯您的問題以包含更改背景顏色的Click代碼？另外，你的'Click'事件是否在綁定中設置了source屬性，或者是邊框的'Background'屬性？如果是第二個，[Depdencey Property Precedence]（http://msdn.microsoft.com/zh-cn/library/ms743230.aspx）指示在對象上設置的值優先於樣式值或觸發值。 – Rachel 2013-04-30 14:35:14
正如@雷切爾問 - 你的'點擊'做什麼？ – XAMeLi 2013-04-30 14:37:07
也許我錯過了一些東西，但不要觸發器都返回相同的值？它們都將'Status'設置爲'{Binding Path = MyStatus，Converter = {StaticResource ColorConverter}}'，它與默認的'Setter'的值相同，所以無論鼠標是否結束，背景顏色都將保持爲靜態它或沒有... – Rachel 2013-04-30 14:43:39