asp.net-mvc <input type="file" /> 的 HTML 助手
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Html helper for <input type="file" />
提问by Graviton
Is there a HTMLHelperfor file upload? Specifically, I am looking for a replace of
有HTMLHelper文件上传吗？具体来说，我正在寻找替代品
<input type="file"/>
using ASP.NET MVC HTMLHelper.
使用 ASP.NET MVC HTMLHelper。
Or, If I use
或者，如果我使用
using (Html.BeginForm())
What is the HTML control for the file upload?
文件上传的HTML控件是什么？
回答by Paulius Zaliaduonis
HTML Upload File ASP MVC 3.
HTML 上传文件 ASP MVC 3.
Model: (Note that FileExtensionsAttribute is available in MvcFutures. It will validate file extensions client side and server side.)
模型：（请注意 FileExtensionsAttribute 在 MvcFutures 中可用。它将验证文件扩展名客户端和服务器端。）
public class ViewModel
{
[Required, Microsoft.Web.Mvc.FileExtensions(Extensions = "csv",
ErrorMessage = "Specify a CSV file. (Comma-separated values)")]
public HttpPostedFileBase File { get; set; }
}
HTML View:
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)
}
Controller action:
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);
}
}
}
回答by balexandre
You can also use:
您还可以使用：
@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>
}
回答by Dan Atkinson
I had this same question a while back and came across one of Scott Hanselman's posts:
不久前我遇到了同样的问题，并遇到了 Scott Hanselman 的一篇文章：
Implementing HTTP File Upload with ASP.NET MVC including Tests and Mocks
使用 ASP.NET MVC 实现 HTTP 文件上传，包括测试和模拟
Hope this helps.
希望这可以帮助。
回答by Tod
Or you could do it properly:
或者你可以正确地做到这一点：
In your HtmlHelper Extension class:
在您的 HtmlHelper 扩展类中：
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));
}
This line:
这一行：
var id = helper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(ExpressionHelper.GetExpressionText(expression));
Generates an id unique to the model, you know in lists and stuff. model[0].Name etc.
生成模型唯一的 id，您在列表和其他东西中知道。模型[0].名称等
Create the correct property in the model:
在模型中创建正确的属性：
public HttpPostedFileBase NewFile { get; set; }
Then you need to make sure your form will send files:
然后你需要确保你的表单会发送文件：
@using (Html.BeginForm("Action", "Controller", FormMethod.Post, new { enctype = "multipart/form-data" }))
Then here's your helper:
那么这是你的帮手：
@Html.FileFor(x => x.NewFile)
回答by BornToCode
Improved version of Paulius Zaliaduonis' answer:
Paulius Zaliaduonis 回答的改进版本：
In order to make the validation work properly I had to change the Model to:
为了使验证正常工作，我必须将模型更改为：
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;
}
}
}
and the view to:
并认为：
@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)
}
This is required because what @Serj Sagan wrote about FileExtension attribute working only with strings.
这是必需的，因为@Serj Sagan 写的关于 FileExtension 属性的内容仅适用于字符串。
回答by Graviton
To use BeginForm, here's the way to use it:
要使用BeginForm，这是使用它的方法：
using(Html.BeginForm("uploadfiles",
"home", FormMethod.POST, new Dictionary<string, object>(){{"type", "file"}})
回答by Eyal
This also works:
这也有效：
Model:
模型：
public class ViewModel
{
public HttpPostedFileBase File{ get; set; }
}
View:
看法：
@using (Html.BeginForm("Action", "Controller", FormMethod.Post, new
{ enctype = "multipart/form-data" }))
{
@Html.TextBoxFor(m => m.File, new { type = "file" })
}
Controller action:
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;
}
回答by Luke Schafer
This is a little hacky I guess, but it results in the correct validation attributes etc being applied
我猜这有点棘手，但它会导致应用正确的验证属性等
@Html.Raw(Html.TextBoxFor(m => m.File).ToHtmlString().Replace("type=\"text\"", "type=\"file\""))
