>我已经将图像存储为字节数组,现在我需要从字节数组中显示它。所以我有一个<img>
标签,我已经在运行时将该标签的来源分配给一个将获取图像的方法。
视图:
document.getElementById("Logo").setAttribute("src",'@Url.Action("GetImage","AdminLogoManager", new { id = Model.Asset.AssetID})');
<img id="Logo" />
控制器中的代码:
private List<LogoModel> LogoModelList
{
get
{
var logoModelList = GetLogoModelListFromSomewhere();
return logoModelList;
}
}
}
public FileContentResult GetImage(int id)
{
LogoModel m = LogoModelList.Find(p => p.Asset.AssetID == id);
return new FileContentResult(m.Asset.Document, "image/jpeg");
}
但它不显示图像。我检查了Chrome调试器,它说:服务器响应错误 500(内部服务器错误)谁能帮我解决这个问题??我知道 LogoModelList 不是空或空的,并且 ID 可能是正确的
PS:它甚至没有调试。我无法在GetImage()
上设置调试点
我困扰的是,我找不到在此处添加的代码的原始来源,但它有效。有人有原始链接,如果您的声誉允许,请随时让我知道或编辑此答案:
帮助程序:
public static class ImageResultHelper
{
public static ImageResult Image( this Controller controller, byte[] imageData, string mimeType )
{
return new ImageResult()
{
ImageData = imageData,
MimeType = mimeType
};
}
public static ImageResult Image( this Controller controller, byte[] imageData, string mimeType, HttpCacheability cacheability, DateTime expires, string eTag )
{
return new ImageResult()
{
ImageData = imageData,
MimeType = mimeType,
Cacheability = cacheability,
Expires = expires,
ETag = eTag
};
}
}
和定制ActionResult
:
public class ImageResult : ActionResult
{
public ImageResult()
{
}
public byte[] ImageData { get; set; }
public string MimeType { get; set; }
public HttpCacheability Cacheability { get; set; }
public string ETag { get; set; }
public DateTime? Expires { get; set; }
public override void ExecuteResult( ControllerContext context )
{
if ( this.ImageData == null )
{
throw new ArgumentNullException( "ImageData" );
}
if ( string.IsNullOrEmpty( this.MimeType ) )
{
throw new ArgumentNullException( "MimeType" );
}
context.HttpContext.Response.ContentType = this.MimeType;
if ( !string.IsNullOrEmpty( this.ETag ) )
{
context.HttpContext.Response.Cache.SetETag( this.ETag );
}
if ( this.Expires.HasValue )
{
context.HttpContext.Response.Cache.SetCacheability( this.Cacheability );
context.HttpContext.Response.Cache.SetExpires( this.Expires.Value );
}
context.HttpContext.Response.OutputStream.Write( this.ImageData, 0, this.ImageData.Length );
}
}
这是我使用内置的 WebImage 类在控制器上创建的方法,改编自以下答案:
Asp.net MVC3 图像缩略图调整大小的想法
WebImage 的好处是您可以设置图像的大小并保持纵横比:
using System.Web.Helpers;
public void GetImageThumbnailFromByteArray(int docId, int width, int height)
{
// Load image from database
var document = productRepository.Documents.SingleOrDefault(f => f.DocumentID == docId);
if (document == null || document.FileContent == null)
{
return;
}
// .FileContent is the image stored as a byte array
var image = document.FileContent;
// .Resize will resize the image on the fly using the passed in width and height.
// The 3rd and 4th params are preserveAspectRatio and preventEnlarge
// .Crop it to remove 1px border at top and left sides (bug in WebImage)
new WebImage(image)
.Resize(width, height, true, true)
.Crop(1, 1)
.Write();
// This will load a default image if no image available
// new WebImage(HostingEnvironment.MapPath(@"~/Content/images/myPic.png")).Write();
}
在剃刀中:
<div>
<a title="Click to download" href="@Url.Action("Download", "Product", new {id = Model.DocumentID})">
<img style="border: solid; border-color: lightgrey; border-width: thin" src="@Url.Action("GetImageThumbnailFromByteArray", "Product", new {docId = Model.DocumentID, width = 250, height = 250})" alt=""/>
</a>
</div>
终于拿到了代码来调试,发现m.Asset.Document是空的!