Editor's Note: Spring

Dundas Resources

Here's a quick run-down of important Dundas resources, to help you find the information you need:

• Dundas Support - This should be your first stop when you've got any questions about Dundas products. Loads of useful articles about Chart, Gauge, Map, Calendar, and Diagram, as well as technologies such as Windows Forms, ASP.NET, Reporting Services, SharePoint, and OLAP.
• Dundas Support Forums - An open forum where Dundas customers and support staff can communicate directly to help solve your problems and provide development ideas and sample code.
• Dundas Technical Newsletter archives - A complete listing of every newsletter, organized by month and article title.
• Dundas Consulting - Got a problem you can't solve yourself, or a deadline that's just too tight or that you can't meet with your current set of resources? Take advantage of our unmatched data visualization expertise!
• The Sample of the Month page is now up-to-date and will be receiving regular updates again. Be sure to check it out!

Horizontal Error Bars (Add-on)

Dundas Chart lets you use error bars in many of the standard chart types, but what if you need error bars for a horizontal chart? Add this easy-to-use add-on to your project and you've got them. Works with Chart for Windows Forms, ASP.NET and Reporting Services.

Selection Zooming in Dundas Map (Add-on)

In Dundas Map, the Viewport.Zoom property determines the zoom level. This property uses percentage values, which can make it difficult to zoom in to a specific set of pixel or geographic coordinates on your Map image. This add-on lets you zoom in to a rectangle defined by either pixel or geographic coordinates. For ASP.NET users, there is also JavaScript to allow client-side selection cursors similar to zooming in Dundas Chart.

Extended Spline Chart Functionality (Add-on)

Currently, a Chart series ignores the specific nature of spline data and only lets you search the data points based on their X value. To find a Y value, you must use one of the X values present in the DataSet using the Series.FindValue() method. This add-on lets you find the Y value for any X value within the DataSet's range, even for X values that aren't present.

General Tips

Tip: Trade Shows

With summer approaching, we're getting ready to attend several industry trade shows. We'll be including information about them here as soon as we've confirmed our attendance so you'll have plenty of time to get signed up.

Microsoft Tech·Ed 2007 - Dundas Data Visualization is a Bronze Sponsor for Microsoft's Tech·Ed 2007 show, June 4-8 in Orlando, Florida. Dundas will be in Booth 614 if you want to say "Hi!"

No Help Viewer Installed

If the Microsoft Document Explorer (the application used to read Microsoft Help files, such as the Dundas documentation) is installed in a non-standard location, you will need to manually install the documentation for your Dundas products. Read on for details about this simple process.

read more »

Tip: Grid Lines on Multiple Chart Areas

Say you've got a form with several bar charts aligned horizontally, so they look like they're all part of the same logical chart. How can you set up Y Axis major grid lines so they span the entire logical chart?

Disable the Axis.LabelStyle, Axis.MajorTickMark and Axis.MinorTickMark properties on all but the leftmost chart. Don't disable the entire Axis on the other charts or the GridLines will not be displayed.

You will also have to adjust the width of the first chart to account for the width of the Y Axis labels (or reduce the width of the other charts).

(This tip comes from a question in the Dundas Support Forum; you can read the original question and response by clicking here.)

Tip: Getting Chart Coordinates in a Click Event

If you attempt to get coordinates from a Chart in its Click event, you can recieve NaN as the answer. How is this possible? If the Chart's areas haven't been calculated previously, the values used by the Axis' PixelPositionToValue() method haven't been initialized.

Use the ChartAreas' ReCalc() method before calling PixelPositionToValue() to make sure the values have been initialized properly.

(This tip comes from a question in the Dundas Support Forum; you can read the original question and response by clicking here.)

Tooltips in Reporting Services

Reporting Services currently has a limitation of one tooltip per control; be aware of this limitation when designing your application. To correctly set the tooltip, don't use the Properties window of VisualStudio. Instead, follow these steps:

1. Right-click your Gauge control, then choose Properties from the context menu.
2. Switch to the Advanced tab.
3. Select the Gauge Control in the dropdown list.
4. Set its ToolTip property.

read more »

ESRI Shapefiles (.shp)

Looking for ESRI Shapefiles (.shp) to use with Map? You're in luck, because we have quite a few of them on the Dundas web site, including US zip codes, US counties, maps with administrative boundaries, geologic data, and lots more.

read more »

Clickable Symbols

If you've got symbols on your map, and you'd like to perform an operation when the user clicks one, use the Map control's Click event and the HitTest() method to figure out which object was clicked:

protected void MapControl1_Click(object sender, ClickEventArgs e)
{
    HitTestResult test = e.MapControl.HitTest(e.X, e.Y);
    if (test.Object is Symbol)
    {
        Symbol symbol = (Symbol)test.Object;
        Response.Redirect(
            ResolveUrl("/Content/Reports/NetworkReports/PlayerConnection.aspx?UserName=" 
                + symbol.Name));
    }
}

read more »

Chart

Q. I'm using a Stacked Bar chart and need to show the sum of the point labels on top of every bar. Is it possible to do this?

A. You can use Annotations to show the sum of a Stacked Bar chart at top of each bar. The steps include:

1. calculate the sum of a stacked bar.
2. create TextAnnotations for each bar.
3. Anchor the annotations to the topmost data points.

read more »

Q. Is it possible to create a custom background gradient in a Windows Forms chart?

A. Chart only accepts values from the GradientType enumeration for its background gradient property. Instead, set the Chart's BackColor to transparent and use its Paint event to draw your custom background.

read more »

Q. Is there a way to force the X Axis to be a fixed pixel width?

A. You can control the Chart's dimensions by setting its Height and Width properties to specific pixel values. The elements inside the Chart will use relative coordinates (0-100). You can convert relative to pixel coordinates using the ValueToPosition() and PixelPositionToValue() methods of the Axis objects.

read more »

Gauge

Q. Can I change a realtime gauge's refresh interval at runtime in ASP.NET?

A. Yes, but you must do it on the client side with JavaScript. Add a button to the page that activates a JavaScript function; in the function, set the Gauge's refreshInterval property.

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Map

Q. Can we use the data from Dundas Map in our applications and ship it to our clients?

A. Yes, although Dundas doesn't guarantee the accuracy of the map data.

read more »

Q. How do I center/zoom on the clicked shape on the map?

A. This can be done using the Click or MouseDown events and the HitTest() method. You can then implement code that centers and zooms if the user clicked on a shape, and does nothing if the user clicked another kind of object.

read more »