maxGraph/dotnet/aspnet/Export.ashx

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<%@ WebHandler Language="C#" Class="Export" %>
using System;
using System.Collections.Generic;
using System.Xml;
using System.Text;
using System.Web;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
using com.mxgraph;
/// <summary>
/// This handler may be used to create bitmap versions of the graphs
/// using a high-level description of the visual appearance so there
/// is no need to create an object representation of the model on
/// the server-side. The description even allows the server to create
/// the bitmaps using a SAX parser. A DOM parser is not required.
///
/// To integrate the image handler with a client application, the client
/// application must be setup to use this handler. This can be done by
/// setting mxEditor.urlImage programmatically or using a config file.
/// </summary>
public class Export : IHttpHandler
{
public void ProcessRequest (HttpContext context)
{
string requestUrl = context.Request.Url.ToString();
string xml = HttpUtility.UrlDecode(context.Request.Params["xml"]);
if (xml != null)
{
context.Response.ContentType = "image/png";
XmlTextReader xmlReader = new XmlTextReader(new StringReader(xml));
mxGraphViewImageReader viewReader = new mxGraphViewImageReader(
xmlReader, Color.White, 4, true, true);
// Use Clip property on viewReader to render a subimage
Image image = mxGraphViewImageReader.Convert(viewReader);
// Displays a Save As... dialog on the client-side
context.Response.AddHeader("Content-Disposition",
"attachment; filename=diagram.png");
// Render BitMap Stream Back To Client
MemoryStream memStream = new MemoryStream();
image.Save(memStream, ImageFormat.Png);
memStream.WriteTo(context.Response.OutputStream);
}
else
{
context.Response.StatusCode = 400; /* Bad Request */
}
}
public bool IsReusable
{
// Return false in case your Managed Handler cannot be reused for another request.
// Usually this would be false in case you have some state information preserved per request.
get { return true; }
}
}