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asp.net mvc 从数据库中读取图片的实现代码

2024-07-10 12:42:15
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首先是创建一个类,继承于ActionResult,记住要引用System.Web.Mvc命名空间,如下:
代码如下:
public class ImageResult : ActionResult
{
public ImageFormat ContentType { get; set; }
public Image image { get; set; }
public string SourceName { get; set; }
public ImageResult(string _SourceName, ImageFormat _ContentType)
{
this.SourceName = _SourceName;
this.ContentType = _ContentType;
}
public ImageResult(Image _ImageBytes, ImageFormat _ContentType)
{
this.ContentType = _ContentType;
this.image = _ImageBytes;
}
public override void ExecuteResult(ControllerContext context)
{
context.HttpContext.Response.Clear();
context.HttpContext.Response.Cache.SetCacheability(HttpCacheability.NoCache);
if (ContentType.Equals(ImageFormat.Bmp)) context.HttpContext.Response.ContentType = "image/bmp";
if (ContentType.Equals(ImageFormat.Gif)) context.HttpContext.Response.ContentType = "image/gif";
if (ContentType.Equals(ImageFormat.Icon)) context.HttpContext.Response.ContentType = "image/vnd.microsoft.icon";
if (ContentType.Equals(ImageFormat.Jpeg)) context.HttpContext.Response.ContentType = "image/jpeg";
if (ContentType.Equals(ImageFormat.Png)) context.HttpContext.Response.ContentType = "image/png";
if (ContentType.Equals(ImageFormat.Tiff)) context.HttpContext.Response.ContentType = "image/tiff";
if (ContentType.Equals(ImageFormat.Wmf)) context.HttpContext.Response.ContentType = "image/wmf";
if (image != null)
{
image.Save(context.HttpContext.Response.OutputStream, ContentType);
}
else
{
context.HttpContext.Response.TransmitFile(SourceName);
}
}
}

然后在 Controller类中创建一个Action.如下:
代码如下:
public ActionResult GetPicture(int id)
{
ICategory server = new CategoryServer();
byte[] buffer = server.getCategoryPicture(id);
if (buffer != null)
{
MemoryStream stream = new MemoryStream(buffer);
System.Drawing.Image image = System.Drawing.Image.FromStream(stream);
ImageResult result = new ImageResult(image, System.Drawing.Imaging.ImageFormat.Jpeg);
return result;
}
return View();
}

这样就可以显示图片了。
下面几种方法可以显示已经存在的图片
方法一:
代码如下:
using System.IO;
public FileResult Image() {
string path = Server.MapPath("/Content/Images/Decorative/");
string filename = Request.Url.Segments[Request.Url.Segments.Length - 1].ToString();
// Uss Path.Combine from System.IO instead of StringBuilder.
string fullPath = Path.Combine(path, filename);
return(new FileResult(fullPath, "image/jpeg"));
}

方法二:
代码如下:
public ActionResult Image(string id)
{
var dir = Server.MapPath("/Images");
var path = Path.Combine(dir, id + ".jpg");
return base.File(path, "image/jpg");
}

方法三:
代码如下:
[AcceptVerbs(HttpVerbs.Get)]
[OutputCache(CacheProfile = "CustomerImages")]
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