C#：含糊不清的匹配异常：找到含糊不清的匹配

我得到一个例外：

AmbiguousMatchException:找到不明确的匹配

当打开我的窗口时，XAML被解析。我有一个基本的ViewModel类。它具有DataGrid的SelectedItem属性

public class BaseViewModel<T> : ViewModel, INotifyPropertyChanged where T : MyClass
{
    protected T _selectedItem;
    public T SelectedItem
    {
        get
        {
            return _selectedItem;
        }
        set
        {
            _selectedItem = value;
            OnPropertyChanged();
        }
    }
}

---

那么，如何使用重写属性而不获取异常呢？

为什么要在派生类中重新定义属性？派生类的type参数应指定属性的类型：

public class MyInheritedClass : BaseViewModel<MyClass>
{
    //no need to define a new SelectedItem property...
}

…并在派生类中重写它：

public override MyClass SelectedItem
{
    get
    {
        return _selectedItem;
    }
    set
    {
        _selectedItem = value;
        OnPropertyChanged();
        //Do other stuff
    }
}

---

如果定义基类中已经存在的属性（或依赖属性的访问器），则会发生这种情况。因为这样你就变得模棱两可了。您必须覆盖（主题：虚拟）或新建（隐藏）它。否则，WPF中发生的反射将处理歧义

例如：

public partial class My : UserControl
{
// this will make the ambiguity with the existing trigges-DP legacy accessor
public int Triggers {get;set;}

// this will not make ambiguities, because it hides the original.
// however it may cause other problems
public new object Background {get;set; }

// also OK, but needs justification as well.
public override object ExistingVirtualProperty {get;set; }
...

---

因为我需要为继承的类做一些特殊的事情。查看新属性中的注释，然后应该在基类中使该属性为虚拟属性，并在派生类中重写它。请参阅我编辑的答案。

public override MyClass SelectedItem
{
    get
    {
        return _selectedItem;
    }
    set
    {
        _selectedItem = value;
        OnPropertyChanged();
        //Do other stuff
    }
}

public partial class My : UserControl
{
// this will make the ambiguity with the existing trigges-DP legacy accessor
public int Triggers {get;set;}

// this will not make ambiguities, because it hides the original.
// however it may cause other problems
public new object Background {get;set; }

// also OK, but needs justification as well.
public override object ExistingVirtualProperty {get;set; }
...