blocks|key|3171843|text|您可能还需要考虑将图像保存到数据库：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3171844|++using+(MemoryStream+mstream+=+new+MemoryStream())
++++++++++++++++{
++++++++++++++++++++if+(context.Request.Browser.Browser+==+"IE")
++++++++++++++++++++++++context.Request.Files[0].InputStream.CopyTo(mstream);
++++++++++++++++++++else
++++++++++++++++++++++++context.Request.InputStream.CopyTo(mstream);

++++++++++++++++++++if+(ValidateIcon(mstream))
++++++++++++++++++++{
++++++++++++++++++++++++Icon+icon+=+new+Icon()+{+ImageData+=+mstream.ToArray(),+MimeType+=+context.Request.ContentType+};
++++++++++++++++++++++++this.iconRepository.SaveOrUpdate(icon);
++++++++++++++++++++}
++++++++++++++++}|code-block|syntax|javascript|3171845|我将其用于定义了NHibernate+-+entity：|3171846|+public+Icon(int+id,+byte[]+imageData,+string+mimeType)
++++{
++++++++this.Id+=+id;
++++++++this.ImageData+=+imageData;
++++++++this.MimeType+=+mimeType;
++++}

++++public+virtual+byte[]+ImageData+{+get;+set;+}

++++public+virtual+string+MimeType+{+get;+set;+}|3171847|然后，您可以将图像作为FileContentResult返回：|3171848|+public+FileContentResult+GetIcon(int?+iconId)
++++{
++++++++try
++++++++{
++++++++++++if+(!iconId.HasValue)+return+null;

++++++++++++Icon+icon+=+this.iconRepository.Get(iconId.Value);

++++++++++++return+File(icon.ImageData,+icon.MimeType);
++++++++}
++++++++catch+(Exception+ex)
++++++++{
++++++++++++Log.ErrorFormat("ImageController:+GetIcon+Critical+Error:+{0}",+ex);
++++++++++++return+null;
++++++++}
++++}|3171849|请注意，这里使用的是ajax提交。否则更容易访问数据流。|3171850|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|W|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|Y|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

You may want to consider saving the image to database also:

<pre><code> using (MemoryStream mstream = new MemoryStream())
 {
 if (context.Request.Browser.Browser == "IE")
 context.Request.Files[0].InputStream.CopyTo(mstream);
 else
 context.Request.InputStream.CopyTo(mstream);

 if (ValidateIcon(mstream))
 {
 Icon icon = new Icon() { ImageData = mstream.ToArray(), MimeType = context.Request.ContentType };
 this.iconRepository.SaveOrUpdate(icon);
 }
 }
</code></pre>

I use this with NHibernate - entity defined:

<pre><code> public Icon(int id, byte[] imageData, string mimeType)
 {
 this.Id = id;
 this.ImageData = imageData;
 this.MimeType = mimeType;
 }

 public virtual byte[] ImageData { get; set; }

 public virtual string MimeType { get; set; }
</code></pre>

Then you can return the image as a FileContentResult:

<pre><code> public FileContentResult GetIcon(int? iconId)
 {
 try
 {
 if (!iconId.HasValue) return null;

 Icon icon = this.iconRepository.Get(iconId.Value);

 return File(icon.ImageData, icon.MimeType);
 }
 catch (Exception ex)
 {
 Log.ErrorFormat("ImageController: GetIcon Critical Error: {0}", ex);
 return null;
 }
 }
</code></pre>

Note that this is using ajax submit. Easier to access the data stream otherwise.

blocks|key|267585|text|自定义验证属性是一种方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|267586|public+class+ValidateFileAttribute+:+RequiredAttribute
{
++++public+override+bool+IsValid(object+value)
++++{
++++++++var+file+=+value+as+HttpPostedFileBase;
++++++++if+(file+==+null)
++++++++{
++++++++++++return+false;
++++++++}

++++++++if+(file.ContentLength+>+1+*+1024+*+1024)
++++++++{
++++++++++++return+false;
++++++++}

++++++++try
++++++++{
++++++++++++using+(var+img+=+Image.FromStream(file.InputStream))
++++++++++++{
++++++++++++++++return+img.RawFormat.Equals(ImageFormat.Png);
++++++++++++}
++++++++}
++++++++catch+{+}
++++++++return+false;
++++}
}|code-block|syntax|javascript|267587|然后在你的模型上应用：|267588|public+class+MyViewModel
{
++++[ValidateFile(ErrorMessage+=+"Please+select+a+PNG+image+smaller+than+1MB")]
++++public+HttpPostedFileBase+File+{+get;+set;+}
}|267589|控制器可能如下所示：|267590|public+class+HomeController+:+Controller
{
++++public+ActionResult+Index()
++++{
++++++++var+model+=+new+MyViewModel();
++++++++return+View(model);
++++}

++++[HttpPost]
++++public+ActionResult+Index(MyViewModel+model)
++++{
++++++++if+(!ModelState.IsValid)
++++++++{
++++++++++++return+View(model);
++++++++}

++++++++//+The+uploaded+image+corresponds+to+our+business+rules+=>+process+it

++++++++var+fileName+=+Path.GetFileName(model.File.FileName);
++++++++var+path+=+Path.Combine(Server.MapPath("~/App_Data"),+fileName);
++++++++model.File.SaveAs(path);

++++++++return+Content("Thanks+for+uploading",+"text/plain");
++++}
}|267591|视图：|267592|@model+MyViewModel

@using+(Html.BeginForm("Index",+"Home",+FormMethod.Post,+new+{+enctype+=+"multipart/form-data"+}))
{
++++@Html.LabelFor(x+=>+x.File)
++++<input+type="file"+name="@Html.NameFor(x+=>+x.File)"+id="@Html.IdFor(x+=>+x.File)"+/>
++++@Html.ValidationMessageFor(x+=>+x.File)
++++<input+type="submit"+value="upload"+/>
}|267593|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|Y|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|10|8|@]|9|@]|A|$]]|$1|Q|3|R|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

A custom validation attribute is one way to go:

<pre><code>public class ValidateFileAttribute : RequiredAttribute
{
 public override bool IsValid(object value)
 {
 var file = value as HttpPostedFileBase;
 if (file == null)
 {
 return false;
 }

 if (file.ContentLength &gt; 1 * 1024 * 1024)
 {
 return false;
 }

 try
 {
 using (var img = Image.FromStream(file.InputStream))
 {
 return img.RawFormat.Equals(ImageFormat.Png);
 }
 }
 catch { }
 return false;
 }
}
</code></pre>

and then apply on your model:

<pre><code>public class MyViewModel
{
 [ValidateFile(ErrorMessage = "Please select a PNG image smaller than 1MB")]
 public HttpPostedFileBase File { get; set; }
}
</code></pre>

The controller might look like this:

<pre><code>public class HomeController : Controller
{
 public ActionResult Index()
 {
 var model = new MyViewModel();
 return View(model);
 }

 [HttpPost]
 public ActionResult Index(MyViewModel model)
 {
 if (!ModelState.IsValid)
 {
 return View(model);
 }

 // The uploaded image corresponds to our business rules =&gt; process it

 var fileName = Path.GetFileName(model.File.FileName);
 var path = Path.Combine(Server.MapPath("~/App_Data"), fileName);
 model.File.SaveAs(path);

 return Content("Thanks for uploading", "text/plain");
 }
}
</code></pre>

and the view:

<pre><code>@model MyViewModel

@using (Html.BeginForm("Index", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
 @Html.LabelFor(x =&gt; x.File)
 &lt;input type="file" name="@Html.NameFor(x =&gt; x.File)" id="@Html.IdFor(x =&gt; x.File)" /&gt;
 @Html.ValidationMessageFor(x =&gt; x.File)
 &lt;input type="submit" value="upload" /&gt;
}
</code></pre>

blocks|key|3171882|text|基于Darin+Dimitrov的答案，我发现非常有用，我有一个改编的版本，允许检查多种文件类型，这是我最初寻找的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3171883|public+override+bool+IsValid(object+value)
++++{
++++++++bool+isValid+=+false;
++++++++var+file+=+value+as+HttpPostedFileBase;

++++++++if+(file+==+null+%7C%7C+file.ContentLength+>+1+*+1024+*+1024)
++++++++{
++++++++++++return+isValid;
++++++++}

++++++++if+(IsFileTypeValid(file))
++++++++{
++++++++++++isValid+=+true;
++++++++}

++++++++return+isValid;
++++}

++++private+bool+IsFileTypeValid(HttpPostedFileBase+file)
++++{
++++++++bool+isValid+=+false;

++++++++try
++++++++{
++++++++++++using+(var+img+=+Image.FromStream(file.InputStream))
++++++++++++{
++++++++++++++++if+(IsOneOfValidFormats(img.RawFormat))
++++++++++++++++{
++++++++++++++++++++isValid+=+true;
++++++++++++++++}+
++++++++++++}
++++++++}
++++++++catch+
++++++++{
++++++++++++//Image+is+invalid
++++++++}
++++++++return+isValid;
++++}

++++private+bool+IsOneOfValidFormats(ImageFormat+rawFormat)
++++{
++++++++List<ImageFormat>+formats+=+getValidFormats();

++++++++foreach+(ImageFormat+format+in+formats)
++++++++{
++++++++++++if(rawFormat.Equals(format))
++++++++++++{
++++++++++++++++return+true;
++++++++++++}
++++++++}
++++++++return+false;
++++}

++++private+List<ImageFormat>+getValidFormats()
++++{
++++++++List<ImageFormat>+formats+=+new+List<ImageFormat>();
++++++++formats.Add(ImageFormat.Png);
++++++++formats.Add(ImageFormat.Jpeg);
++++++++formats.Add(ImageFormat.Gif);
++++++++//add+types+here
++++++++return+formats;
++++}
}|code-block|syntax|javascript|3171884|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Based on Darin Dimitrov's answer which I have found very helpful, I have an adapted version which allows checks for multiple file types, which is what I was initially looking for. 

<pre><code>public override bool IsValid(object value)
 {
 bool isValid = false;
 var file = value as HttpPostedFileBase;

 if (file == null || file.ContentLength &gt; 1 * 1024 * 1024)
 {
 return isValid;
 }

 if (IsFileTypeValid(file))
 {
 isValid = true;
 }

 return isValid;
 }

 private bool IsFileTypeValid(HttpPostedFileBase file)
 {
 bool isValid = false;

 try
 {
 using (var img = Image.FromStream(file.InputStream))
 {
 if (IsOneOfValidFormats(img.RawFormat))
 {
 isValid = true;
 } 
 }
 }
 catch 
 {
 //Image is invalid
 }
 return isValid;
 }

 private bool IsOneOfValidFormats(ImageFormat rawFormat)
 {
 List&lt;ImageFormat&gt; formats = getValidFormats();

 foreach (ImageFormat format in formats)
 {
 if(rawFormat.Equals(format))
 {
 return true;
 }
 }
 return false;
 }

 private List&lt;ImageFormat&gt; getValidFormats()
 {
 List&lt;ImageFormat&gt; formats = new List&lt;ImageFormat&gt;();
 formats.Add(ImageFormat.Png);
 formats.Add(ImageFormat.Jpeg);
 formats.Add(ImageFormat.Gif);
 //add types here
 return formats;
 }
}
</code></pre>

blocks|key|264405|text|这里有一种使用viewmodel的方法，请看一下这里的全部代码|type|unstyled|depth|inlineStyleRanges|entityRanges|data|264406|使用FileSize和FileTypes创建视图模型，如下所示|264407|public+class+ValidateFiles
{
++++[FileSize(10240)]
++++[FileTypes("doc,docx,xlsx")]
++++public+HttpPostedFileBase+File+{+get;+set;+}
}|code-block|syntax|javascript|264408|创建自定义属性|264409|public+class+FileSizeAttribute+:+ValidationAttribute
{
++++private+readonly+int+_maxSize;

++++public+FileSizeAttribute(int+maxSize)
++++{
++++++++_maxSize+=+maxSize;
++++}
++++//.....
++++//.....
}



public+class+FileTypesAttribute+:+ValidationAttribute
{
++++private+readonly+List<string>+_types;

++++public+FileTypesAttribute(string+types)
++++{
++++++++_types+=+types.Split(',').ToList();
++++}+
++++//....
++++//...
}|264410|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Here is a way to do it using viewmodel, take a look at whole code here

<a href="http://codeanalyze.com/Articles/Details/6/MVC-5-Validate-Posted-Files-view-models-viewmodels" rel="nofollow noreferrer">Asp.Net MVC file validation for size and type</a>
Create a viewmodel as shown below with FileSize and FileTypes 

<pre><code>public class ValidateFiles
{
 [FileSize(10240)]
 [FileTypes("doc,docx,xlsx")]
 public HttpPostedFileBase File { get; set; }
}
</code></pre>

Create custom attributes

<pre><code>public class FileSizeAttribute : ValidationAttribute
{
 private readonly int _maxSize;

 public FileSizeAttribute(int maxSize)
 {
 _maxSize = maxSize;
 }
 //.....
 //.....
}



public class FileTypesAttribute : ValidationAttribute
{
 private readonly List&lt;string&gt; _types;

 public FileTypesAttribute(string types)
 {
 _types = types.Split(',').ToList();
 } 
 //....
 //...
}
</code></pre>

blocks|key|3171937|text|以及asp.net核心中的文件长度验证|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|3171938|public+async+Task<IActionResult>+MyAction()
{
++++var+form+=+await+Request.ReadFormAsync();
++++if+(form.Files+!=+null+&&+form.Files.Count+==+1)
++++{
++++++++var+file+=+form.Files[0];
++++++++if+(file.Length+>+1+*+1024+*+1024)
++++++++{
++++++++++++ModelState.AddModelError(String.Empty,+"Maximum+file+size+is+1+Mb.");
++++++++}
++++}
++++//+action+code+goes+here
}|code-block|syntax|javascript|3171939|entityMap^0|2|9|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

And file length validation in asp.net core:

<pre><code>public async Task&lt;IActionResult&gt; MyAction()
{
 var form = await Request.ReadFormAsync();
 if (form.Files != null &amp;&amp; form.Files.Count == 1)
 {
 var file = form.Files[0];
 if (file.Length &gt; 1 * 1024 * 1024)
 {
 ModelState.AddModelError(String.Empty, "Maximum file size is 1 Mb.");
 }
 }
 // action code goes here
}
</code></pre>

I have a Create action that takes an entity object and a HttpPostedFileBase image. The image does not belong to the entity model.

I can save the entity object in the database and the file in disk, but I am not sure how to validate these business rules:

<ul>
<li>Image is required</li>
<li>Content type must be "image/png"</li>
<li>Must not exceed 1MB</li>
</ul>

How to validate uploaded file in ASP.NET MVC?

数据库

数据流

我有一个使用entity对象和HttpPostedFileBase图像的Create操作。图像不属于实体模型。我可以将实体对象保存在数据库中，将文件保存在磁盘中，但我不确定如何验证这些业务规则：映像类型必须是requiredContent "image/png"Must 不能超过1MB

问如何在ASP.NET MVC中验证上传的文件？
EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何在ASP.NET MVC中验证上传的文件？EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何在ASP.NET MVC中验证上传的文件？
EN