论坛直接建立新帖传送文件不能成功

app/views/forums/show.html.erb

@@ -2,7 +2,7 @@
 <div id="add-memo" style="display:none;">
 	<h3><%=l(:label_memo_new)%></h3>
 	<% if User.current.logged? %>
-	<%= labelled_form_for(@memo, :url => forum_memos_path(@forum)) do |f|  %>
+	<%= labelled_form_for(@memo, :url => forum_memos_path(@forum), :html => {:multipart => true} ) do |f|  %>
 	<% if @memo.errors.any? %>
 		<div id="error_explanation">
 			<h2><%= pluralize(@memo.errors.count, "error") %> prohibited this memo from being saved:</h2>