RoutedPropertyChangedEventArgs<T>.OldValue 属性

定义

获取由属性更改事件报告的属性的旧值。Gets the previous value of the property as reported by a property changed event.

public:
 property T OldValue { T get(); };
public T OldValue { get; }
member this.OldValue : 'T
Public ReadOnly Property OldValue As T

属性值

T

泛型值。The generic value. RoutedPropertyChangedEventArgs<T> 的实际实现中,此属性的泛型类型将替换为该实现的约束类型。In a practical implementation of the RoutedPropertyChangedEventArgs<T>, the generic type of this property is replaced with the constrained type of the implementation.

注解

此属性的值和类型约束将由RoutedPropertyChangedEventArgs<T>构造函数的类型参数建立。The value and type constraint of this property will be established by the RoutedPropertyChangedEventArgs<T> constructor's type arguments.

适用于