是否有用于文件上传的 HTMLHelper
?具体而言,我正在寻找一个替代品。
<input type="file"/>
使用ASP.NET MVC HTMLHelper。或者,如果我使用 。
using (Html.BeginForm())
是否有用于文件上传的 HTMLHelper
?具体而言,我正在寻找一个替代品。
<input type="file"/>
使用ASP.NET MVC HTMLHelper。using (Html.BeginForm())
HTML 上传文件 ASP MVC 3。
模型:(请注意,FileExtensionsAttribute 可在 MvcFutures 中使用。它将在客户端和服务器端验证文件扩展名。)
public class ViewModel
{
[Required, Microsoft.Web.Mvc.FileExtensions(Extensions = "csv",
ErrorMessage = "Specify a CSV file. (Comma-separated values)")]
public HttpPostedFileBase File { get; set; }
}
HTML视图:
@using (Html.BeginForm("Action", "Controller", FormMethod.Post, new
{ enctype = "multipart/form-data" }))
{
@Html.TextBoxFor(m => m.File, new { type = "file" })
@Html.ValidationMessageFor(m => m.File)
}
控制器动作:
[HttpPost]
public ActionResult Action(ViewModel model)
{
if (ModelState.IsValid)
{
// Use your file here
using (MemoryStream memoryStream = new MemoryStream())
{
model.File.InputStream.CopyTo(memoryStream);
}
}
}
您也可以使用:
@using (Html.BeginForm("Upload", "File", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
<p>
<input type="file" id="fileUpload" name="fileUpload" size="23" />
</p>
<p>
<input type="submit" value="Upload file" /></p>
}
public static MvcHtmlString FileFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression)
{
return helper.FileFor(expression, null);
}
public static MvcHtmlString FileFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression, object htmlAttributes)
{
var builder = new TagBuilder("input");
var id = helper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(ExpressionHelper.GetExpressionText(expression));
builder.GenerateId(id);
builder.MergeAttribute("name", id);
builder.MergeAttribute("type", "file");
builder.MergeAttributes(new RouteValueDictionary(htmlAttributes));
// Render tag
return MvcHtmlString.Create(builder.ToString(TagRenderMode.SelfClosing));
}
这行代码:
var id = helper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(ExpressionHelper.GetExpressionText(expression));
生成一个唯一的id,用于模型中的列表等。例如:model[0].Name等。
在模型中创建正确的属性:
public HttpPostedFileBase NewFile { get; set; }
接下来需要确保您的表单能够发送文件:
@using (Html.BeginForm("Action", "Controller", FormMethod.Post, new { enctype = "multipart/form-data" }))
然后,以下是需要翻译的内容:
@Html.FileFor(x => x.NewFile)
Paulius Zaliaduonis的回答有所改进:
为了使验证正常工作,我必须更改模型:
public class ViewModel
{
public HttpPostedFileBase File { get; set; }
[Required(ErrorMessage="A header image is required"), FileExtensions(ErrorMessage = "Please upload an image file.")]
public string FileName
{
get
{
if (File != null)
return File.FileName;
else
return String.Empty;
}
}
}
@using (Html.BeginForm("Action", "Controller", FormMethod.Post, new
{ enctype = "multipart/form-data" }))
{
@Html.TextBoxFor(m => m.File, new { type = "file" })
@Html.ValidationMessageFor(m => m.FileName)
}
这是必需的,因为@Serj Sagan所写关于FileExtension属性仅适用于字符串的内容。
使用BeginForm
,以下是使用它的方法:
using(Html.BeginForm("uploadfiles",
"home", FormMethod.POST, new Dictionary<string, object>(){{"type", "file"}})
这也可以运行:
模型:
public class ViewModel
{
public HttpPostedFileBase File{ get; set; }
}
视图:
@using (Html.BeginForm("Action", "Controller", FormMethod.Post, new
{ enctype = "multipart/form-data" }))
{
@Html.TextBoxFor(m => m.File, new { type = "file" })
}
控制器动作:
[HttpPost]
public ActionResult Action(ViewModel model)
{
if (ModelState.IsValid)
{
var postedFile = Request.Files["File"];
// now you can get and validate the file type:
var isFileSupported= IsFileSupported(postedFile);
}
}
public bool IsFileSupported(HttpPostedFileBase file)
{
var isSupported = false;
switch (file.ContentType)
{
case ("image/gif"):
isSupported = true;
break;
case ("image/jpeg"):
isSupported = true;
break;
case ("image/png"):
isSupported = true;
break;
case ("audio/mp3"):
isSupported = true;
break;
case ("audio/wav"):
isSupported = true;
break;
}
return isSupported;
}
我觉得这有点取巧,但它确保了正确的验证属性等被应用。
@Html.Raw(Html.TextBoxFor(m => m.File).ToHtmlString().Replace("type=\"text\"", "type=\"file\""))
HttpPostedFileBase
的文件扩展名。请参考这个 stackoverflow 答案。 - skeletank