泛型类无法接受具有直接行到类型限制的泛型的对象

Question

我有一个c＃数据类，定义了一个如下所示的继承链：

public abstract class EntityBaseCore
public abstract class EntityBase : EntityBaseCore
public partial class AdmSite : EntityBase

这样定义的泛型类：

public abstract class ViewModelSecurityBase<T> : Screen, where T : EntityBaseCore
public abstract class EditorViewModelBase<T> : ViewModelSecurityBase<T> where T : EntityBaseCore

我的视图模型类如下所示：

public class SiteViewModel : EditorViewModelBase<AdmSite>

失败

The type 'Yargo.DataModel.AdmSite' cannot be used as type parameter 'T' in the generic type or method 'Yargo.Common.ViewModel.EditorViewModelBase'. There is no implicit reference conversion from 'Yargo.DataModel.AdmSite' to 'Yargo.DataModel.EntityBaseCore'

AdmSite和EntityBaseCode之间的继承链似乎是直接的。我不明白为什么会失败。

Answer 1

以下代码似乎对我有用。

public class Screen { }
public abstract class EntityBaseCore
{    }

public abstract class EntityBase : EntityBaseCore
{    }
public partial class AdmSite : EntityBase
{    }

public abstract class ViewModelSecurityBase<T> : Screen where T : EntityBaseCore
{    }
public abstract class EditorViewModelBase<T> : ViewModelSecurityBase<T> where T : EntityBaseCore
{    }

public class SiteViewModel : EditorViewModelBase<AdmSite>
{    }