绑定到静态类实例中的属性 [英] Binding to a property within a static class instance

问题描述

我要实现的目标

我有一个WPF应用程序(仅用于测试)，我想将标签的文本(内容)绑定到某个位置的属性.想法是，当用户选择其他语言时，将更改此属性值.当属性更改时，我希望标签文本以新值更新.

I have a WPF application (it's just for testing) and I want to bind the text (Content) of a label to a property somewhere. The idea is that this property value will be changed when the user chooses a different language. When the property changes, I want the label text to update with the new value.

我尝试过的事情

我试图为标签值创建一个具有静态属性的静态类.例如:

I tried to create a static class with a static property for the label value. For example:

public static class Language
{
    public static string Name = "Name";
}

然后我可以像这样使用XAML将这个值绑定到我的标签上:

I then was able to bind this value to my label using XAML like so:

Content="{Binding Source={x:Static lang:Language.Name}}"

这对于显示名称"的初始值效果很好.问题是，当Name属性更改时，标签值不会更改.

And this worked fine for showing the initial value of "Name". The problem is, when the Name property changes the label value doesn't change.

因此，返回到绘图板(Google).然后我发现了这个答案，听起来完全像我所需要的.所以这是我对此的新尝试:

So, back to the drawing board (Google). Then I found this answer which sounded exactly like what I needed. So here was my new attempt at this:

public class Language
{
    public static Language Instance { get; private set; }
    static Language() { Instance = new Language(); }
    private Language() { }

    private string name = "Name";
    public string Name { get { return name; } set { name = value; } }
}

通过我的绑定将其更改为:

With my binding changed it this:

Content="{Binding Source={x:Static lang:Language.Instance}, Path=Name}"

这仍然会导致相同的问题.

This still results in the same problem.

问题

我在这里想念什么?值更改后如何更新标签?

What am I missing here? How can I get the label to update when the value is changed?

推荐答案

那根本不是一个属性.试试:

That simply isn't a property. Try:

public class Language
{
    public static Language Instance { get; private set; }
    static Language() { Instance = new Language(); }
    private Language() { Name = "Name"; }

    public string Name {get;private set;}
}

或带有更改通知:

public class Language : INotifyPropertyChanged
{
    public static Language Instance { get; private set; }
    static Language() { Instance = new Language(); }
    private Language() { }

    private string name = "Name";
    public string Name
    {
        get { return name; }
        set { SetValue(ref name, value);}
    }
    protected void SetValue<T>(ref T field, T value,
        [CallerMemberName]string propertyName=null)
    {
        if (!EqualityComparer<T>.Default.Equals(field, value))
        {
            field = value;
            OnPropertyChanged(propertyName);
        }
    }
    protected virtual void OnPropertyChanged(
        [CallerMemberName]string propertyName=null)
    {
        var handler = PropertyChanged;
        if (handler != null)
            handler(this, new PropertyChangedEventArgs(propertyName));
    }
    public event PropertyChangedEventHandler PropertyChanged;
}

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