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Editor's Note: Happy New Year!

It might be a little late to be wishing a Happy New Year, but nonetheless there it is. This year is set to be another great year for Dundas Software and in turn a great year for all of our clients. We have an exciting new Add-On to offer in this newsletter, as well as quite a few new articles on the Support Site.

As with 2006, 2007 will bring updates to our core product lines and even brand new products. I should also mention that the Support Forum is now in high gear with a lot of new people registering every day. There is quite a bit of material on the forum now, so if you have any questions regarding our products this is definitely a good place to check along with the support site.

Terrence Sheflin

In this Issue: January 23, 2007


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Variable Width Column Chart (Add-On)

Most chart types plot data so that the X-value determines where each point is plotted along the X-axis. The variable width column plots column charts with the width determined by its X-value. This makes each column stacked against each other along the X-axis.

To use this static utility class, add the file VariableWidth.cs or VariableWidth.vb to your project or your website's App_Code directory. Add the Dundas.Charting.Utilities namespace at the top of your code file and then use the VariableWidth.ConvertSeries() method. You can modify any of the standard series properties on a variable width column series, before or after conversion, aside from the following:

  • The Series.Palette property should only be set before conversion (see the "Series palettes" section within the full article).
  • Any sorting done to the data must be done before conversion.
  • Label and MarkerStyle must be set using the VariableWidth class after conversion.
  • The AxisLabel (as well as string type X-values) must be set before conversion and displayed by calling SetAxisLabel after conversion (see "Series X-axis labels" within the full article).
  • XValue and YValues should not be changed after conversion as the Points collection is altered during the conversion process.

To change the data within a variable width column series you must clear the points, re-add the data from your data source and re-convert the series. A code snippet illustrating how to do this and many other tasks along with the full class source code is available in the full article.

Tips n' Tricks Chart | Gauge | Map

General Tips

Dundas Products Work With Visual Studio 2005 SP1
Dundas Chart for .NET, Dundas Map for .NET and Dundas Gauge for .NET have all been updated to work with the new patch released for Visual Studio 2005. Dundas Software takes compatibility very seriously and we take pride in knowing our controls work with the most cutting-edge technology available. If you have Visual Studio 2005 SP1 and are experiencing any problems, please ensure you have the latest version of the control. If you are still experiencing any issues with the latest version of the control, then please contact us immediately and we will work to resolve it.

How to Create a Grouped Pie Chart
A grouped pie chart has the advantage of showing both an overview of data and a drill down within the same image. Creating a grouped pie chart using Dundas Chart for .NET is a simple process: first, you need to create two pie series, two chart areas and assign each series to its own chart area. Make sure the chart area for the inner pie is added last as this ensures that the correct z-order is used for the chart areas. The series representing the outer pie can be of type Doughnut if you do not want the labels to be covered by the inner pie. After you have populated the 2 series with data, you can use the code within the full article to position one chart area over the other.
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Save an Image Directly Into the HTTP Response
In ASP.NET images can be saved only into a bidirectional stream. The most common approach to saving an image created by Gauge into the response is to write it directly to the HTTP Response object. However, the HTTP Response object is not a bidirectional stream. The solution is to first write the image into a memory stream and then write the memory stream to Response.OutputStream:

MemoryStream stream = new MemoryStream();
gaugeControl.SaveAsImage(stream, GaugeImageFormat.Png);

Please note that while the full article uses Dundas Map as an example, it does work with the Gauge as well (as per the above code).
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Scrollwheel Zooming in Dundas Map for ASP.NET
Zoom operations using the mouse wheel are convenient because they let the user zoom in and out interactively without having to move the mouse cursor to the Zoom Panel on the Map control. While scrollwheel zooming is built into Dundas Map for Windows Forms by default, it is not currently in the ASP.NET version. As such we have written an article which describes how to accomplish scrollwheel zooming on the web with a script which works across multiple browsers.

The code provided in the full article changes the zoom level when the scrollwheel moves if the mouse is positioned over the Map's image. The zoom level changes in exponential increments equal to the difference between ticks on the zoom panel. You can change the Viewport.Zoom, Viewport.MinimumZoom, Viewport.MaximumZoom and ZoomPanel.TickCount, and the provided code will handle the changes. If you are using a ZoomPanel.ZoomType setting other than the default value of Exponential, you may want to modify the code and script to achieve desired results.
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Dundas Q & A Chart | Gauge | Map

Chart for .NET

Q. My ASP.NET control does not work properly with Chart version 5.5 with AJAX and I am receiving a System.NullReferenceException.
A. The event validation for some ASP.NET controls (such as the ListBox and HtmlInputText controls) are not suitable to be used with AJAX. To solve this problem, please do one of the following:

  1. On the top of the ASP page set EnableEventValidation = "false", e.g. <%@ Page ... EnableEventValidation = "false" %>
  2. Instead of using an ASP.NET control, consider using the HTML equivalent instead. For example, if an ASP.NET ListBox is being used then the select tag can be used instead: <select id=".." runat="server"></select>

Chart for .NET - OLAP Services

Q. How can I save the OLAP chart to an Excel file?
A. Dundas Chart .NET - OLAP Services version 5.5 allows you to directly save the data in your chart to an Excel file. In the sample framework included with our ASP.NET solution there is a sample which demonstrates how to do this named "Creating a Custom Layout using OLAP Services". If you are using Windows Forms, then please consult the full article which contains a code snippet on how to accomplish this using Windows Forms.
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Gauge for .NET

Q. Can Dundas Gauge for ASP.NET support the 508 accessibility standards?
A. Since Dundas Gauge is normally generated as an image on the client browser, the only part of these standards applicable to Gauge is section 1194.22 paragraph a: non-text elements must be described by an "alt" or "longdesc" attribute. To set these attributes within Gauge, code similar to the following can be used: GaugeContainer1.Attributes["alt"] = "Gauge with a value of " + GaugeContainer1.Values[0].Value;

If you are using map areas in the Gauge, for example by setting tooltips, hyperlinks, or the MapAreaAttributes property on any gauge element, you should also set an "alt" attribute in the MapAreaAttributes property or add one to it: MapAreaAttributes = "alt='Alternative text'";.

Q. I'm using Internet Explorer 7 and the Sample Framework for Dundas Gauge and/or Online Documentation is very slow. What's wrong?
A. This is an issue which was found and fixed by Microsoft within Internet Explorer 7. To get the fix for IE7, please visit Once IE7 is patched, the issue will no longer occur.

Map for .NET

Q. How can I improve the performance of Dundas Map?
A. There are a number of things that can be modified in order to make Map perform better. These include: Content Caching (ASP.NET), Optimize for Panning (WinForms), Simplification, Detail Hiding and Loading Shape Files at run-time. One option may have more impact on your project than another depending on what functionality your solution contains, so it is left to the developer's discretion to make the choice of which to use. Each option is discussed in more detail within the full article.
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Map for Reporting Services

Q. I'm having problems using Dundas Map for Reporting Services on a 64-bit machine after the install.
A. Normally the installer will copy RSMapInstaller.exe and run it at the end of the install process. However, if you are using a 64-bit machine, the installer may fail to run this file. In this case it is possible to run the file yourself in order to complete the install process. To run the RSMapInstaller.exe file manually, navigate to C:\Program Files (x86)\Dundas Software\Maps\Reporting Services\Tools (default install location). If this does not solve the issue, please refer to the full article for manual installation steps.
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