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In most usage scenarios, the data displayed in a Microsoft Chart control comes from some dynamic source, such as from a database query. The appearance of the chart can be modified dynamically, as well; past installments in this article series showed how to programmatically customize the axes, labels, and other appearance-related settings. However, it is possible to statically define the chart’s data and appearance strictly through the control’s declarative markup. One of the demos examined in the Getting Started article rendered a column chart with seven columns whose labels and values were defined statically in the <asp:Series> tag’s <Points> collection. Given this functionality, it should come as no surprise that the Microsoft Chart Controls also support serialization . Serialization is the process of persisting the state of a control or an object to some other medium, such as to disk. Deserialization is the inverse process, and involves taking the persisted data and recreating the control or object. With just a few lines of code you can persist the appearance settings, the data, or both to a file on disk or to any stream. Likewise, it takes just a few lines of codes to reconstitute a chart from the persisted information.

Filtering Database Data with Parameters , an earlier installment in this article series, showed how to filter the data returned by ASP.NET’s data source controls. In a nutshell, the data source controls can include parameterized queries whose parameter values are defined via parameter controls. For example, the SqlDataSource can include a parameterized SelectCommand , such as: SELECT * FROM Books WHERE Price > @Price . Here, @Price is a parameter ; the value for a parameter can be defined declaratively using a parameter control . ASP.NET offers a variety of parameter controls, including ones that use hard-coded values, ones that retrieve values from the querystring, and ones that retrieve values from session, and others. Perhaps the most useful parameter control is the ControlParameter, which retrieves its value from a Web control on the page. Using the ControlParameter we can filter the data returned by the data source control based on the end user’s input. While the ControlParameter works well with most types of Web controls, it does not work as expected with the CheckBoxList control. The ControlParameter is designed to retrieve a single property value from the specified Web control, but the CheckBoxList control does not have a property that returns all of the values of its selected items in a form that the CheckBoxList control can use. Moreover, if you are using the selected CheckBoxList items to query a database you’ll quickly find that SQL does not offer out of the box functionality for filtering results based on a user-supplied list of filter criteria. The good news is that with a little bit of effort it is possible to filter data based on the end user’s selections in a CheckBoxList control.

The end of the year is upon us, 2009 is about to be in the books. When closing out a year I like to take a look back at the articles I wrote over the year and see which ones resonated the most with readers. Which ones generated the most reader emails? Which ones were read the most? Such a retrospective analysis highlights what content was of most interest to developers in the trenches, and this data is used to guide article topics in the new year. While cataloging this year’s most popular articles I thought others might find the data interesting. Such a “Best Of 2009″ list would give both regular and new readers a chance to discover (or rediscover) the most favored content from the year. So here it is – a list and synopsis of the 2009’s most popular articles on 4GuysFromRolla.com. Read More >

Charts are typically used to provide a static snapshot of data. The chart’s underlying data might be based on various user inputs, but in the end the chart, once rendered, represents the end of the reporting workflow. However, other scenarios allow for a more interactive user experience. For example, in the Creating Drill Down Reports article we looked at how to configure the Chart control to allow the user to drill into a particular data point. Specifically, the demo contained a column chart showing the number of products in each category in the Northwind database. Clicking on a column whisked the user to a new page that details about the products in that category. Also, in certain situations the data populating the chart might be arriving from a sensor or some other source that is constantly being updated. In that case, we might want a real time chart whose data is periodically (and automatically) refreshed to show the latest data

The Microsoft Chart controls make it easy to take data from a database or some other data store and present it as a chart. As discussed in Plotting Chart Data , the Chart controls offer a myriad of ways to get data into a chart. You can add the data programmatically, point-by-point, or you can bind an ADO.NET DataTable directly to the Chart. You can even use declarative data source controls, like the SqlDataSource or ObjectDataSource controls. In addition to converting your specified data points into a chart image, the Chart controls also include a wealth of statistical formulae that you can use to analyze the plotted data. For example, with a single line of code you determine the mean (average) value for data in a particular series. Likewise, with one line of code you can get the median, variance, or standard deviation. These values can be displayed as text on the page or as a stripe line on the chart itself

The SqlBulkCopy class provides a mechanism for efficiently importing large amounts of data into a Microsoft SQL Server database. Compared to importing data by executing one INSERT statement for each record to import, SqlBulkCopy is noticeably faster when importing thousands (or more) records. In a nutshell, importing data using SqlBulkCopy entails creating a SqlBulkCopy object, specifying the destination database and table, and providing the data to import in the form of a DataTable , DataRow , or DataReader. In Using SqlBulkCopy To Perform Efficient Bulk SQL Operations we looked at how to use SqlBulkCopy to programmatically import data from an uploaded Excel spreadsheet into a SQL Server database. While Using SqlBulkCopy To Perform Efficient Bulk SQL Operations showed how to use the SqlBulkCopy class, it did not explore how SqlBulkCopy imports fare in the face of an error. What happens if, when importing a total of 10,000 records, an error occurs when importing record number 501?

Each series in a chart is composed of a set of data points, which are modeled via the DataPoint class. For most chart types, the two key attributes of a data point are its X and Y value. For example, in a line chart the X value indicates the position of the data point along the X axis, while the Y value represents the position of the data point along the Y axis. Ditto for a column chart, although it may help to think of the Y value as the height of the column.

jQuery is a lightweight, cross-browser JavaScript library designed to ease JavaScript’s most common tasks, including inspecting and manipulating the Document Object Model (DOM) and making out of band HTTP requests to support AJAX functionality. In plain English, jQuery makes it easy to perform client-side tasks like adding or removing attributes or CSS classes to elements in the DOM, or showing or hiding elements on the page in response to a user action (such as clicking a button). jQuery is used by many popular Web 2.0 sites to help implement rich, interactive features. jQuery can certainly be used in an ASP.NET application, although integrating client-side script into a Web Forms application can sometimes be a bit trying. JavaScript development fits more naturally with ASP.NET MVC applications; in fact, the ASP.NET MVC framework includes the jQuery libraries. What’s more, Microsoft has announced that jQuery will be included with Visual Studio 2010 and beyond . I recently had the opportunity to use jQuery in a intranet-based line of business Web Forms application. This application has a number of reporting screens that use a GridView control to display the report results. Users often want to filter the results to get a more concise snapshop of the data they are interested in, and to that end many of these reports include a filtering user interface, which is a series of drop-downs, checkboxes, and textboxes, through which they can apply various filtering criteria.

The Microsoft Chart controls make it easy to take data – such as sales numbers, website traffic statistics, and so on – and turn it into a chart, which can be saved to an image file or displayed from a web page. In Plotting Chart Data we examined a myriad of ways to turn data into a chart, including: plotting the chart data point by point; binding data to the Chart’s Points collection; programmatically binding data structured data to the chart; and declaratively binding data using one of ASP.NET’s data source controls, such as the SqlDataSource or ObjectDataSource. Oftentimes, web pages that display charts include user interface elements that let the user filter or sort the plotted data. For example, when viewing a chart of expenses, the user may want to only show expenses between two dates, or may want to sort the expenses by category. One way to provide such functionality is to sort or filter the data before binding it to the chart. Alternatively, you can bind the original data to the chart and then instruct the Chart control to sort the data, or to apply a filter. This article shows how to use these sorting and filtering capabilities. Read on to learn more! Read More >

The Microsoft Chart Controls provide ASP.NET developers with an API and a Web control for creating and displaying charts in a web page. Behind the scenes, the Microsoft Chart Controls take the data to be plotted and dynamically generates an image. This image can be generated using one of three techniques: the Chart Web control can generate the image and save it to the web server’s file system in a specified location; the Chart control can generate the image and store it in memory, session, or elsewhere, and have that image served by a built-in HTTP Handler, ChartHttpHandler ; or the Chart control can send back the binary contents of the chart image directly to the browser. The chart image can be rendered using one of four image types: PNG , JPG , BMP , or EMF . And when rendering a JPG you can specify its compression level. Regardless of the image file type and the technique used to generate the image, the Chart Web control renders an <img> element whose src attribute references the image (or the image-producing HTTP Handler or ASP.NET page). When a browser requests a web page with a Chart control on it, it receives this <img> element as part of the page’s rendered markup and then makes a request to the URL specified in the src attribute (just like it does for any other image on a web page). The chart image file the browser requests either already exists in which case its contents are returned, or the image is dynamically-generated. Either way, the end result is that the browser is sent back the chart as an image file, which is displays. This article explores the three different techniques the Microsoft Chart Controls has at its disposal for generating chart images. We’ll look at how to use each option, enumerate the pros and cons, and discuss when to consider using one option over another. Read on to learn more! Read More >