Se necesita tener .net pero seguro que a muchos programadores de asp os valdra de mucho, como a mi.
Funciona de la siguiente manera.
Metes en cualquier pagina, ya sea asp o html la imagen con este formato y fuera.
Código HTML:
<img src="thumbnail.aspx?ForceAspect=False&Width=140&image=images/foto1.jpg"> Thumbnail.aspx
Código:
<%@ Page Language="C#" ContentType="text/html" ResponseEncoding="iso-8859-1" %>
<script language="C#" runat="server">
void Page_Load(Object sender, EventArgs e)
{
try{
Response.Cache.VaryByParams["Image;Width;Height;ForceAspect"] = true;
Response.ContentType = "image/jpeg";
System.Collections.Hashtable imageOutputFormatsTable = new System.Collections.Hashtable();
imageOutputFormatsTable.Add(System.Drawing.Imaging.ImageFormat.Gif.Guid, System.Drawing.Imaging.ImageFormat.Gif);
imageOutputFormatsTable.Add(System.Drawing.Imaging.ImageFormat.Jpeg.Guid, System.Drawing.Imaging.ImageFormat.Jpeg);
imageOutputFormatsTable.Add(System.Drawing.Imaging.ImageFormat.Bmp.Guid, System.Drawing.Imaging.ImageFormat.Gif);
imageOutputFormatsTable.Add(System.Drawing.Imaging.ImageFormat.Tiff.Guid, System.Drawing.Imaging.ImageFormat.Jpeg);
imageOutputFormatsTable.Add(System.Drawing.Imaging.ImageFormat.Png.Guid, System.Drawing.Imaging.ImageFormat.Jpeg);
string imageLocation;
bool forceaspect = true;
int newHeight;
int newWidth;
int reqHeight = 100;
int reqWidth = 100;
int origHeight;
int origWidth;
imageLocation = Server.MapPath(Request.QueryString["Image"]);
if (Request.QueryString["Height"] != null){
reqHeight = Convert.ToInt32(Request.QueryString["Height"]);
}
if (Request.QueryString["ForceAspect"] != null){
forceaspect = Convert.ToBoolean(Request.QueryString["ForceAspect"]);
}
if(Request.QueryString["Width"] != null){
reqWidth = Convert.ToInt32(Request.QueryString["Width"]);
}
if (Request.QueryString["ForceAspect"] == "true"){
forceaspect = true;
}
System.Drawing.Bitmap origBitmap = new System.Drawing.Bitmap(imageLocation);
origHeight = origBitmap.Height;
origWidth = origBitmap.Width;
if (forceaspect){
//Force Aspect Change
newHeight = reqHeight;
newWidth = reqWidth;
}
else{
//Landscape
newWidth = reqWidth;
newHeight = (int)(((double)origBitmap.Height / (double)origBitmap.Width) * reqWidth);
}
System.Drawing.Bitmap outputImage = new System.Drawing.Bitmap(origBitmap, newWidth, newHeight);
//outputImage.SetResolution(24, 24); //use this line for lower resolution thumbnails
outputImage.SetResolution(72, 72);
//outputImage.InterpolationMode = InterpolationMode.HighQualityBicubic;
System.Drawing.Imaging.ImageFormat outputFormat = (System.Drawing.Imaging.ImageFormat)imageOutputFormatsTable[origBitmap.RawFormat.Guid];
outputImage.Save(Response.OutputStream, outputFormat);
outputImage.Dispose();
origBitmap.Dispose();
}
catch (Exception ex){
//log error so we may know the problem. you need to have write permits, of course on log path
System.IO.StreamWriter sw=null;
try{
sw=new System.IO.StreamWriter(Server.MapPath("error.txt"),true);
sw.WriteLine("Error : " + ex.Message + " processing " + Request.QueryString["Image"]);
}
catch{}
finally{sw.Close();}
//now display the error image
Response.Redirect("thumberror.gif");
}
}
</script>
Yo lo utilizo en mis portales programados con ASP y va de maravilla.
Un Saludo.
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