c# - 从 DependencyProperty PropertyChangedCallback 获取父对象

Question

我想在每次更改属性时执行一些代码。以下在一定程度上起作用:

public partial class CustomControl : UserControl
{
        public bool myInstanceVariable = true;
        public static readonly DependencyProperty UserSatisfiedProperty =
            DependencyProperty.Register("UserSatisfied", typeof(bool?),
            typeof(WeeklyReportPlant), new FrameworkPropertyMetadata(new PropertyChangedCallback(OnUserSatisfiedChanged)));


        private static void OnUserSatisfiedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            Console.Write("Works!");
        }
}

当 UserSatisfiedProperty 的值改变时，这会打印“Works”。问题是我需要访问调用 OnUserSatisfiedChanged 的​​ CustomControl 实例以获取 myInstanceVariable 的值。我该怎么做？

Answer 1

实例通过 DependencyObject d 参数传递。您可以将其转换为您的 WeeklyReportPlant 类型:

public partial class WeeklyReportPlant : UserControl
{
    public static readonly DependencyProperty UserSatisfiedProperty =
        DependencyProperty.Register(
            "UserSatisfied", typeof(bool?), typeof(WeeklyReportPlant),
            new FrameworkPropertyMetadata(new PropertyChangedCallback(OnUserSatisfiedChanged)));

    private static void OnUserSatisfiedChanged(
        DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var instance = d as WeeklyReportPlant;
        ...
    }
}