UI

Question

我花了最后一小时试图在google和stackoverflow中找到答案。我遵循了不同的建议和建议，但到目前为止没有任何工作。我目前的代码如下：

public class GlobalManager : ViewModelBase
{
    static object _LockObject_GFS = new object();
    static double _GlobalFontSize;
    public static double GlobalFontSize
    {
        get
        {
            lock (_LockObject_GFS)
            {
                _GlobalFontSize = GetGlobalResource<double>(LambdaHelper.MemberToString(() => GlobalFontSize));
                return _GlobalFontSize;
            }
        }
        set
        {
            lock (_LockObject_GFS)
            {
                if (_GlobalFontSize != value)
                {
                    _GlobalFontSize = value;
                    SetGlobalResource(value, LambdaHelper.MemberToString(() => GlobalFontSize));
                    NotifyStaticPropertyChanged(() => GlobalFontSize);
                }
            }
        }
    }
}

吸气鬼＆amp; setter都被称为。 NotifyStaticPropertyChanged有效，我的用户界面无法更新。我添加了一个TextBlock来检查它是否更新。显然它没有。

<TextBlock Text="{Binding Path=(global:GlobalManager.GlobalFontSize), Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>

如果我在我的VM（当前DataContext）中定义了一个属性，并将其绑定到TextBlock，则会使用当前值正确更新。

目前，DependencyProperty的{​​{1}} Value绑定到此属性以更新字体大小。 （Slider）

IsSnapToTickEnabled="True"

如何使绑定与静态属性一起正常工作？ public double GlobalFontSize { get { return GlobalManager.GlobalFontSize; } set { GlobalManager.GlobalFontSize = value; NotifyPropertyChanged(() => GlobalFontSize); } } 事件不为空。

StaticPropertyChanged

编辑1：

StaticPropertyChanged?.Invoke(null, new PropertyChangedEventArgs(propertyName));

Answer 1

确保您的GetGlobalResource和SetGlobalResource方法按预期工作，并确保您的事件签名正确无误。

您可以参考以下工作示例实现并将其与您的实施进行比较：

public class GlobalManager
{
    static object _LockObject_GFS = new object();
    static double _GlobalFontSize;
    public static double GlobalFontSize
    {
        get
        {
            lock (_LockObject_GFS)
            {
                return _GlobalFontSize;
            }
        }
        set
        {
            lock (_LockObject_GFS)
            {
                if (_GlobalFontSize != value)
                {
                    _GlobalFontSize = value;
                    NotifyStaticPropertyChanged(()=> GlobalFontSize);
                }
            }
        }
    }

    public static event EventHandler<PropertyChangedEventArgs> StaticPropertyChanged;

    public static void NotifyStaticPropertyChanged(string propertyName)
    {
        StaticPropertyChanged?.Invoke(null, new PropertyChangedEventArgs(propertyName));
    }

    public static void NotifyStaticPropertyChanged<T>(Expression<Func<T>> property)
    {
        var expr = property.Body as MemberExpression;
        if (expr == null)
            throw new ArgumentException("Lambda does not contain member expression. () => MyClassOrObject.Property");
        NotifyStaticPropertyChanged(expr.Member.Name);
    }
}

编辑：如果事件是在基类中定义的，它不起作用。

public abstract class MyBaseViewModel
{
    public static event EventHandler<PropertyChangedEventArgs> StaticPropertyChanged;

    public static void NotifyStaticPropertyChanged(string propertyName)
    {
        StaticPropertyChanged?.Invoke(null, new PropertyChangedEventArgs(propertyName));
    }

    public static void NotifyStaticPropertyChanged<T>(Expression<Func<T>> property)
    {
        var expr = property.Body as MemberExpression;
        if (expr == null)
            throw new ArgumentException("Lambda does not contain member expression. () => MyClassOrObject.Property");
        NotifyStaticPropertyChanged(expr.Member.Name);
    }
}

public class GlobalManager : MyBaseViewModel
{
    static object _LockObject_GFS = new object();
    static double _GlobalFontSize = 10.0;
    public static double GlobalFontSize
    {
        get
        {
            lock (_LockObject_GFS)
            {
                return _GlobalFontSize;
            }
        }
        set
        {
            lock (_LockObject_GFS)
            {
                if (_GlobalFontSize != value)
                {
                    _GlobalFontSize = value;
                    NotifyStaticPropertyChanged("GlobalFontSize");
                }
            }
        }
    }
}

必须在属性所在的同一个类中定义StaticPropertyChangedEvent才能使绑定更新：

View is not getting notified when value of static Property Changes