DependencyObject.GetValue(DependencyProperty) 方法

定义

DependencyObject 的此实例返回依赖属性的当前有效值。Returns the current effective value of a dependency property on this instance of a DependencyObject.

public:
 System::Object ^ GetValue(System::Windows::DependencyProperty ^ dp);
public object GetValue (System.Windows.DependencyProperty dp);
member this.GetValue : System.Windows.DependencyProperty -> obj
Public Function GetValue (dp As DependencyProperty) As Object

参数

dp
DependencyProperty

要检索其值的属性的 DependencyProperty 标识符。The DependencyProperty identifier of the property to retrieve the value for.

返回

返回当前有效值。Returns the current effective value.

异常

指定 dp 或其值无效,或者指定 dp 不存在。The specified dp or its value was invalid, or the specified dp does not exist.

注解

有效的值是属性系统返回给请求该值的任何调用方的属性的值。The effective value is the value of the property that is returned by the property system to any caller that is requesting the value. 有效的值是属性系统计算所有可能的输入,这些输入都参与属性系统值的优先级。The effective value is the result of the property system having evaluated all the possible inputs that participate in the property system value precedence. 这包括强制和动画。This includes coercion and animation. 有关详细信息,请参阅依赖属性值优先级For more information, see Dependency Property Value Precedence.

此方法从不返回 UnsetValueThis method will never return UnsetValue. @No__t 为属性系统的一个 sentinel 值,该值在内部使用并偶尔通过强制回调公开。The UnsetValue is a sentinel value for the property system that is used in various capacities internally and occasionally also exposed through coercion callbacks.

如果不确定属性的类型应该是什么,则可以查询请求的依赖属性的标识符,以确定是否有更具体的 PropertyType 可将返回值转换为。If you are not sure what the property's type should be, you can query the identifier of the requested dependency property to determine whether there is a more specific PropertyType that the return value can be converted to.

适用于

另请参阅