问题
We can get a ModelExpression using this property in a TagHelper:
[HtmlAttributeName("asp-for")]
public ModelExpression For { get; set; }
I somehow managed* to have a ViewModel wich has a ModelExpression property:
public class TemplateViewModel
{
public ModelExpression For { get; set; }
}
Everytime I try to pass it, the Model expression is For from TemplateViewModel, not the real Expression wich is stored into For:
@model TemplateViewModel
<input asp-for="@Model.For" class="form-control"/>
Above results in:
<input class="form-control" type="text" id="For" name="For" value="Microsoft.AspNetCore.Mvc.ViewFeatures.ModelExpression" />
I expected, the input, which is described by the ModelExpression instead of literaly a ModelExpression for the ModelExpression.
*since I want to have a Template View for an TagHelper using IHtmlHelper::PartialView(). This example is heavy minimized. My main motiviation is to create a single <form-group for="" /> TagHelper, which is generating a Bootstrap Form Group.
回答1:
ModelExpression is handled as a special case in the Razor Compiler, so this isn't going to work directly. Since the compiler is open source, you could suggest a patch to ignore cases where the property is itself a ModelExpression. In the mean time, you're going to need to use a different type of property in your tag helper, to help you get a reference to the actual ModelExpression. Perhaps public Func<ModelExpression> ForAccessor { get; set; }?
来源：https://stackoverflow.com/questions/47125008/is-it-possible-to-pass-modelexpression-to-a-taghelper