Charting in ASP.NET, ASP.NET Chart Controls for .NET 3.5 SP1

Here is a HelloWorld sample on the new ASP.NET Charting control.


To begin with, install the free Microsoft Chart Controls and the "Tools for VS 2008 for Chart Controls" from here and here

Note that if you don’t install the Tools for VS 2008 for Chart controls, the Chart Server Control doesnt show up in the Toolbox

Once you are done with the installation, restart Visual Studio if you are already running the same (of course, save your work)

1. Start Visual Studio 2008 and create a File – New – ASP.NET Website or a Web Application

2. From the ToolBox, under Data tab, pick up the “Chart” control (the icon would be a series of colored bar graphs) and drag and drop it into the page.

3. Click on the smart tag for configuring the Chart control and Choose DataSource

4. Select “Database” and provide the connection string to your database server (in my case I chose Northwind)

5. Choose to save the connection string etc., and select the Database table (in my case I chose “Category Sales for 1997”)

6. Click “Finish” to complete the process.

7. Now if you run the page you will NOT get the Chart Control.

8. You need to select the Properties of the Chart Control from design view.

9. Make sure under “Data” DataSource is set to “SqlDataSource1” unless you gave a different name and DataMember is set to “DefaultView”

10. Under “Series” in Properties, click on the tab to open up the “Series Collection Editor”.

11. Scroll down the Series1 Properties to DataSource section.

12. Specify “CategoryName” as the XValueMember and “CategorySales” for YValueMembers and click Ok.

13. Build the page and hit F5 to run the page.

14. You will be able to see the Chart in your webpage.

15. Right Click on the chart and you would be able to see that it is an image generated dynamically that can be saved as a “.png” file.

You can download a comprehensive list of samples from here and verify the different implementations and source code for the same. For more details, visit the forums here

Silverlight : Where did my ComboBox selected item go?

You might have noticed that sometimes the item in the selection box of a combo box disappears when you reopen the drop-down of the combo.

For example, in the following image, "Arial" is selected,

but doesn't show up in the selection box when the drop-down is reopened.

In contrast, in the following ComboBox, the selected item, "Courier New", is visible in the selection box when the drop-down is reopened.

Here's the code for the first combo box:

The reason the selected item disappears is because a UIElement cannot be in the visual tree more than once. In the first case, I've explicitly created ComboBoxItems and set their content to font names. ComboBoxItem is a UIElement and when it is in the drop-down, it can't be shown in the selection box. When the drop down is closed the UIElement is temporarily moved in the visual tree to be shown as the selected item. This occurs for all UIElements in a Silverlight combo box.

CLR objects that are not derived from UIElement do not have this limitation. In the second case the items are added to the combo box through a binding. The combo box is bound to a collection of strings:

ItemsSource="{Binding}" />

ObservableCollection fonts =
new ObservableCollection();
fonts.Add("Arial");
fonts.Add("Courier New");
fonts.Add("Times New Roman");
FontsCombo.DataContext = fonts;

When CLR objects are used to populate a combo box, UIElements are automatically generated for them using the data template (in this case the default data template is a TextBlock). Two different UIElements are created so CLR objects can be shown in both the selection box and drop-down at the same time.

Hopefully this clears up any confusion. Also this info is now in the online docs.

Kaushik