将泛型类型从类型字典传递给泛型方法？

Question

我有大量的表单都来自基类FormBase。要激活/告诉他们我用下面的泛型方法：

public T ShowForm<T>() where T : FormBase, new() 
{ 
    FormBase form = _activeForms.FirstOrDefault(f => f is T); 

    if (form != null) 
     form.BringToFront(); 
    else 
    { 
     form = new T(); 

     IListView view = form as IListView; 
     if (view != null) 
      view.ParentView = this; 

     _activeForms.Add(form); 
     form.MdiParent = this; 
     form.Show(); 
    } 

    return (T)form; 
} 

现在我想用一本字典，这样我可以轻松地添加更多的形式进来，而不必维持一个巨大的switch声明。

是否有可能有像Dictionary<string, Type>这样的字典并将Type传递给泛型方法？

Answer 1

在我看来，这是情况下，当泛型方法应换不通用的。考虑以下代码：

private FormBase ShowForm(Type formType) 
    { 
     FormBase form = _activeForms.FirstOrDefault(f => f.GetType() == formType); 

     if (form != null) 
      form.BringToFront(); 
     else 
     { 
      form = (FormBase)Activator.CreateInstance(formType); 

      IListView view = form as IListView; 
      if (view != null) 
       view.ParentView = this; 

      _activeForms.Add(form); 
      form.MdiParent = this; 
      form.Show(); 
     } 

     return form; 
    } 

    public T ShowForm<T>() where T : FormBase, new() 
    { 
     return (T)ShowForm(typeof(T)); 
    } 

然后，当表单类型是未知的静态，你可以叫非通用版本的方法：

var form = ShowForm(typeof(SomeForm)); 

Answer 2

是的，你可以使用反射：

var formType = typeof(SomeForm); // substitute with read from dictionary 

// Get ShowForm<T> 
var showFormMethod = typeof(YourClass).GetMethod("ShowForm"); 

// Convert to ShowForm<SomeForm> 
var showFormMethodSpecific = showFormMethod.MakeGenericMethod(formType); 

// Call method 
var yourClass = new YourClass(); // holder of ShowForm 
object form = showFormMethodSpecific.Invoke(yourClass, null); 

// form is now of type SomeForm