此代码无效

// remove the Step variable from the model state

// if you want the changes in the model to be

// taken into account

ModelState.Remove("Step");

model.Step = 2;

...因为HiddenFor always(！)从ModelState读取而不是模型本身 . 如果它没有找到“Step”键，它将产生该变量类型的默认值，在这种情况下它将为0

这是解决方案 . 我是为自己写的，但不介意分享它，因为我看到很多人都在为这个顽皮的HiddenFor帮手挣扎 .

public static class CustomExtensions

{

public static MvcHtmlString HiddenFor2(this HtmlHelper htmlHelper, Expression> expression)

{

ReplacePropertyState(htmlHelper, expression);

return htmlHelper.HiddenFor(expression);

}

public static MvcHtmlString HiddenFor2(this HtmlHelper htmlHelper, Expression> expression, object htmlAttributes)

{

ReplacePropertyState(htmlHelper, expression);

return htmlHelper.HiddenFor(expression, htmlAttributes);

}

public static MvcHtmlString HiddenFor2(this HtmlHelper htmlHelper, Expression> expression, IDictionary htmlAttributes)

{

ReplacePropertyState(htmlHelper, expression);

return htmlHelper.HiddenFor(expression, htmlAttributes);

}

private static void ReplacePropertyState(HtmlHelper htmlHelper, Expression> expression)

{

string text = ExpressionHelper.GetExpressionText(expression);

string fullName = htmlHelper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(text);

ModelStateDictionary modelState = htmlHelper.ViewContext.ViewData.ModelState;

ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);

if (modelState.ContainsKey(fullName))

{

ValueProviderResult currentValue = modelState[fullName].Value;

modelState[fullName].Value = new ValueProviderResult(metadata.Model, Convert.ToString(metadata.Model), currentValue.Culture);

}

else

{

modelState[fullName] = new ModelState

{

Value = new ValueProviderResult(metadata.Model, Convert.ToString(metadata.Model), CultureInfo.CurrentUICulture)

};

}

}

}

然后你可以像往常一样在你看来使用它：

@Html.HiddenFor2(m => m.Id)

值得一提的是它也适用于收藏品 .