更新时间:2023-02-25 19:14:29
您不能发送复杂的对象是这样的:
<%= Url.Action(GetImageForArticle,资源,新的{文章=项目})%GT;
只有简单的标量的属性:
<%= Url.Action(GetImageForArticle,资源,新{
ID = item.Id,
美孚= item.StringFoo,
酒吧= item.IntegerBar
})%GT;
因此,在这种情况下,一个很好的做法是只发送ID:
<%= Url.Action(GetImageForArticle,资源,新{ID = item.Id})%GT;
再有你的控制器动作取不管它是存储给这个ID对应型号:
公众的ActionResult GetImageForArticle(INT ID)
{
ArticleSummary文章= _someRepository.GetArticle(ID);
如果(文章== NULL ||!article.ContainsValidThumbNail())
{
返回null;
}
返回文件(article.ThumbNail,article.ThumbNaiType);
}
Why is a null parameter being passed to the following controller action?
public FileContentResult GetImageForArticle(ArticleSummary article)
{
if (article == null || !article.ContainsValidThumbNail()) return null;
return File(article.ThumbNail, article.ThumbNaiType);
}
from the following partial view:
<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<IEnumerable<AkwiMemorial.Models.ArticleSummary>>" %>
<%if (Model.Count() > 0)
{ %>
<table>
<% foreach (var item in Model)
{ %>
<tr>
<td>
<img src='<%=Url.Action("GetImageForArticle", "Resources", new { article = item })%>' alt=""/>
</td>
</tr>
<% } %>
</table>
You cannot send complex objects like this:
<%=Url.Action("GetImageForArticle", "Resources", new { article = item })%>
Only simple scalar properties:
<%=Url.Action("GetImageForArticle", "Resources", new {
Id = item.Id,
Foo = item.StringFoo,
Bar = item.IntegerBar
})%>
So a good practice in this case is to only send an id:
<%=Url.Action("GetImageForArticle", "Resources", new { id = item.Id }) %>
and then have your controller action fetch the corresponding model from wherever it is stored give this id:
public ActionResult GetImageForArticle(int id)
{
ArticleSummary article = _someRepository.GetArticle(id);
if (article == null || !article.ContainsValidThumbNail())
{
return null;
}
return File(article.ThumbNail, article.ThumbNaiType);
}