Я связывании Width
из TextBox
к ActualWidth
его содержащего Grid
следующим образом:WPF конвертер странное поведение
<TextBlock
Grid.Column="0"
Text="WorkPortalView UserControl"
TextTrimming="CharacterEllipsis"
Foreground="White"
Margin="5"
Width="{Binding ActualWidth, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Grid}}, Converter={StaticResource textWidthConverter}, diag:PresentationTraceSources.TraceLevel=High}" />
Как показано на рисунке, я использую конвертер, следующим образом:
class TextWidthConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
double? d = value as double?;
if (d == null)
return null;
return (d/2);
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotSupportedException("Cannot convert back");
}
}
Странно, что показанный код работает нормально. Однако, если я заменил оператор return (d/2)
на return (d - 75D)
, он, похоже, отправил бесконечный цикл изменений свойств.
Вот выход из диагностики трассировки тег для г/2:
System.Windows.Data Warning: 71 : Lookup ancestor of type Grid: queried Grid (hash=19487651)
System.Windows.Data Warning: 70 : RelativeSource.FindAncestor found Grid (hash=19487651)
System.Windows.Data Warning: 76 : BindingExpression (hash=35097890): Activate with root item Grid (hash=19487651)
System.Windows.Data Warning: 106 : BindingExpression (hash=35097890): At level 0 - for Grid.ActualWidth found accessor DependencyProperty(ActualWidth)
System.Windows.Data Warning: 102 : BindingExpression (hash=35097890): Replace item at level 0 with Grid (hash=19487651), using accessor DependencyProperty(ActualWidth)
System.Windows.Data Warning: 99 : BindingExpression (hash=35097890): GetValue at level 0 from Grid (hash=19487651) using DependencyProperty(ActualWidth): '417.6'
System.Windows.Data Warning: 78 : BindingExpression (hash=35097890): TransferValue - got raw value '417.6'
System.Windows.Data Warning: 80 : BindingExpression (hash=35097890): TransferValue - user's converter produced '208.8'
System.Windows.Data Warning: 87 : BindingExpression (hash=35097890): TransferValue - using final value '208.8'
Вот выход из диагностики трассировки теге D - 75D:
System.Windows.Data Warning: 94 : BindingExpression (hash=58235710): Got PropertyChanged event from Grid (hash=43090134) for ActualWidth
System.Windows.Data Warning: 99 : BindingExpression (hash=58235710): GetValue at level 0 from Grid (hash=43090134) using DependencyProperty(ActualWidth): '429.6'
System.Windows.Data Warning: 78 : BindingExpression (hash=58235710): TransferValue - got raw value '429.6'
System.Windows.Data Warning: 80 : BindingExpression (hash=58235710): TransferValue - user's converter produced '354.6'
System.Windows.Data Warning: 87 : BindingExpression (hash=58235710): TransferValue - using final value '354.6'
System.Windows.Data Warning: 94 : BindingExpression (hash=58235710): Got PropertyChanged event from Grid (hash=43090134) for ActualWidth
System.Windows.Data Warning: 99 : BindingExpression (hash=58235710): GetValue at level 0 from Grid (hash=43090134) using DependencyProperty(ActualWidth): '441.6'
System.Windows.Data Warning: 78 : BindingExpression (hash=58235710): TransferValue - got raw value '441.6'
System.Windows.Data Warning: 80 : BindingExpression (hash=58235710): TransferValue - user's converter produced '366.6'
System.Windows.Data Warning: 87 : BindingExpression (hash=58235710): TransferValue - using final value '366.6'
System.Windows.Data Warning: 94 : BindingExpression (hash=58235710): Got PropertyChanged event from Grid (hash=43090134) for ActualWidth
System.Windows.Data Warning: 99 : BindingExpression (hash=58235710): GetValue at level 0 from Grid (hash=43090134) using DependencyProperty(ActualWidth): '453.6'
System.Windows.Data Warning: 78 : BindingExpression (hash=58235710): TransferValue - got raw value '453.6'
System.Windows.Data Warning: 80 : BindingExpression (hash=58235710): TransferValue - user's converter produced '378.6'
System.Windows.Data Warning: 87 : BindingExpression (hash=58235710): TransferValue - using final value '378.6'
System.Windows.Data Warning: 94 : BindingExpression (hash=58235710): Got PropertyChanged event from Grid (hash=43090134) for ActualWidth
System.Windows.Data Warning: 99 : BindingExpression (hash=58235710): GetValue at level 0 from Grid (hash=43090134) using DependencyProperty(ActualWidth): '465.6'
System.Windows.Data Warning: 78 : BindingExpression (hash=58235710): TransferValue - got raw value '465.6'
System.Windows.Data Warning: 80 : BindingExpression (hash=58235710): TransferValue - user's converter produced '390.6'
System.Windows.Data Warning: 87 : BindingExpression (hash=58235710): TransferValue - using final value '390.6'
System.Windows.Data Warning: 94 : BindingExpression (hash=58235710): Got PropertyChanged event from Grid (hash=43090134) for ActualWidth
System.Windows.Data Warning: 99 : BindingExpression (hash=58235710): GetValue at level 0 from Grid (hash=43090134) using DependencyProperty(ActualWidth): '477.6'
System.Windows.Data Warning: 78 : BindingExpression (hash=58235710): TransferValue - got raw value '477.6'
System.Windows.Data Warning: 80 : BindingExpression (hash=58235710): TransferValue - user's converter produced '402.6'
System.Windows.Data Warning: 87 : BindingExpression (hash=58235710): TransferValue - using final value '402.6'
System.Windows.Data Warning: 94 : BindingExpression (hash=58235710): Got PropertyChanged event from Grid (hash=43090134) for ActualWidth
System.Windows.Data Warning: 99 : BindingExpression (hash=58235710): GetValue at level 0 from Grid (hash=43090134) using DependencyProperty(ActualWidth): '489.6'
System.Windows.Data Warning: 78 : BindingExpression (hash=58235710): TransferValue - got raw value '489.6'
System.Windows.Data Warning: 80 : BindingExpression (hash=58235710): TransferValue - user's converter produced '414.6'
System.Windows.Data Warning: 87 : BindingExpression (hash=58235710): TransferValue - using final value '414.6'
System.Windows.Data Warning: 94 : BindingExpression (hash=58235710): Got PropertyChanged event from Grid (hash=43090134) for ActualWidth
System.Windows.Data Warning: 99 : BindingExpression (hash=58235710): GetValue at level 0 from Grid (hash=43090134) using DependencyProperty(ActualWidth): '501.6'
System.Windows.Data Warning: 78 : BindingExpression (hash=58235710): TransferValue - got raw value '501.6'
System.Windows.Data Warning: 80 : BindingExpression (hash=58235710): TransferValue - user's converter produced '426.6'
System.Windows.Data Warning: 87 : BindingExpression (hash=58235710): TransferValue - using final value '426.6'
System.Windows.Data Warning: 94 : BindingExpression (hash=58235710): Got PropertyChanged event from Grid (hash=43090134) for ActualWidth
System.Windows.Data Warning: 99 : BindingExpression (hash=58235710): GetValue at level 0 from Grid (hash=43090134) using DependencyProperty(ActualWidth): '513.6'
System.Windows.Data Warning: 78 : BindingExpression (hash=58235710): TransferValue - got raw value '513.6'
System.Windows.Data Warning: 80 : BindingExpression (hash=58235710): TransferValue - user's converter produced '438.6'
System.Windows.Data Warning: 87 : BindingExpression (hash=58235710): TransferValue - using final value '438.6'
System.Windows.Data Warning: 94 : BindingExpression (hash=58235710): Got PropertyChanged event from Grid (hash=43090134) for ActualWidth
System.Windows.Data Warning: 99 : BindingExpression (hash=58235710): GetValue at level 0 from Grid (hash=43090134) using DependencyProperty(ActualWidth): '525.6'
System.Windows.Data Warning: 78 : BindingExpression (hash=58235710): TransferValue - got raw value '525.6'
System.Windows.Data Warning: 80 : BindingExpression (hash=58235710): TransferValue - user's converter produced '450.6'
System.Windows.Data Warning: 87 : BindingExpression (hash=58235710): TransferValue - using final value '450.6'
System.Windows.Data Warning: 94 : BindingExpression (hash=58235710): Got PropertyChanged event from Grid (hash=43090134) for ActualWidth
System.Windows.Data Warning: 99 : BindingExpression (hash=58235710): GetValue at level 0 from Grid (hash=43090134) using DependencyProperty(ActualWidth): '537.6'
System.Windows.Data Warning: 78 : BindingExpression (hash=58235710): TransferValue - got raw value '537.6'
System.Windows.Data Warning: 80 : BindingExpression (hash=58235710): TransferValue - user's converter produced '462.6'
System.Windows.Data Warning: 87 : BindingExpression (hash=58235710): TransferValue - using final value '462.6'
System.Windows.Data Warning: 94 : BindingExpression (hash=58235710): Got PropertyChanged event from Grid (hash=43090134) for ActualWidth
System.Windows.Data Warning: 99 : BindingExpression (hash=58235710): GetValue at level 0 from Grid (hash=43090134) using DependencyProperty(ActualWidth): '549.6'
System.Windows.Data Warning: 78 : BindingExpression (hash=58235710): TransferValue - got raw value '549.6'
System.Windows.Data Warning: 80 : BindingExpression (hash=58235710): TransferValue - user's converter produced '474.6'
System.Windows.Data Warning: 87 : BindingExpression (hash=58235710): TransferValue - using final value '474.6'
System.Windows.Data Warning: 94 : BindingExpression (hash=58235710): Got PropertyChanged event from Grid (hash=43090134) for ActualWidth
System.Windows.Data Warning: 99 : BindingExpression (hash=58235710): GetValue at level 0 from Grid (hash=43090134) using DependencyProperty(ActualWidth): '561.6'
System.Windows.Data Warning: 78 : BindingExpression (hash=58235710): TransferValue - got raw value '561.6'
System.Windows.Data Warning: 80 : BindingExpression (hash=58235710): TransferValue - user's converter produced '486.6'
System.Windows.Data Warning: 87 : BindingExpression (hash=58235710): TransferValue - using final value '486.6'
Все мысли на объясняет это поведение конвертера?
Является ли сетка изменением размера с помощью изменения размера TextBlock? –
@Wonko: Нет, но похоже, что это связано с взаимодействием с другим столбцом (Width = Auto в обоих столбцах), который запускается, когда я не оставляю достаточно ширины для второго столбца; установка уравнения на d-100D (оставляя больше места для другого столбца), кажется, исправляет проблему. Я все еще не знаю условия запуска, чтобы знать, что «достаточно» для другого столбца, почему он не просто обрезает другой столбец или делает другое окончательное определение. – Bill