如何创建只读布尔依赖项属性,该属性在两个其他依赖项属性之间返回"And"操作

Question

如何创建自定义只读布尔依赖项属性,该属性返回And两个自定义布尔依赖项属性之间的操作,例如(A,B),

当A或B发生变化时,我希望触发result属性.

任何帮助实现这一目标!

Answer 1

第1部分:依赖关系.

public static readonly DependencyProperty Source1Property =
    DependencyProperty.Register(
        "Source1",
        typeof(bool),
        typeof(MyControl),
        new FrameworkPropertyMetadata(false, new PropertyChangedCallback(UpdateTarget)));

public bool Source1
{
    get { return (bool)GetValue(Source1Property); }
    set { SetValue(Source1Property, value); }
}

void UpdateTarget(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
    MyControl self = (MyControl)d;
    d.Target = d.Source1 && d.Source2;
}

第2部分:只读

internal static readonly DependencyPropertyKey TargetPropertyKey =
    DependencyProperty.RegisterReadOnly(
        "Target",
        typeof(bool),
        typeof(MyControl),
        new PropertyMetadata(false));

public static readonly DependencyProperty TargetProperty =
    TargetPropertyKey.DependencyProperty;

public bool Target
{
    get { return (bool)GetValue(TargetProperty); }
    protected set { SetValue(TargetPropertyKey, value); }
}

免责声明:我没有尝试第2部分.

第3部分:
如果您没有定义源依赖项属性,则可以执行以下操作:

DependencyPropertyDescriptor dpd = DependencyPropertyDescriptor.FromProperty(
        MyControl.Source1Property,
        typeof(MyControl)));
if (dpd != null)
    dpd.AddValueChanged(this, UpdateTarget);