|By Michael Earls||
|May 20, 2005 11:00 AM EDT||
One of the most basic ways to navigate within an application is by use of a tab control. Tabs are easy to use and users are very familiar with them. There have been many implementations of tab controls for Web applications, but they had often required advanced client-side script that was only supported in a few browsers, or they required extensive and confusing server-side include files. ASP.NET 2.0 provides a few things that make this easier to do with no dependency on functional code. In this article I'll show you how you can use the new features of ASP.NET 2.0 to easily create a tab control for your Web application.
To get started, create a new Web site (use your favorite language) on your computer and call it TabDemo. ASP.NET 2.0 introduces a new set of data providers and controls based on the notion of a site map. The site map is the central data store for site navigation data. Let's start by defining a simple site map that we can use for our site. Add a new sitemap to the site (use the default name of Web.sitemap). Listing 1 shows a simple sitemap that will demonstrate the tabs nicely.
Now that we have our sitemap, we can continue with the actual user interface. To get the most benefit from the tab control, we'll use a master page to keep everything together. Add a new master page to your Web site and call it MasterPage.master (see Figure 1).
In order to make our tabs seem as though they're physically connected to our content, we'll need to create a master HTML table to contain the tabs. Delete the code between the <form> and </form> tags in the MasterPage.master file and replace it with the HTML in Listing 2.
That will give us the main table that will hold all of our content (including our tab control). Now we need to define the table that actually holds our tabs and the tab "panels." Let's take a look at Listing 3. It shows the HTML that we should put into the TD with the ID of ContentContainer.
Notice the use of the TD with the CSS class TabMenuSpacer. This cell forces the empty area behind the tabs to take up all of the excess space to the right of the menu. We need to add the SiteMapDataSource to our page so that the menu will be bound to our site map. This is easy to do. Simply add the following code just below the main table:
<asp:SiteMapDataSource ID="TabMenuSitemap" runat="server" ShowStartingNode="false" />
This adds a new SiteMapData-Source to the page. Since we used the default name of Web.sitemap for our site map, ASP.NET will automatically use it as the main site map for the site, so we don't have to do anything else. If you add another site map to the site, you'll need to define a new site map provider to the web.config file that points to your new site map, and then set the SiteMapProvider property of the SiteMapDataSource to your new site map provider. It's also important to point out that we set the ShowStartingNode property to false. We did this because we have a flat site map and we don't want to show the top-most parent node for our menu (since the site map is defined in XML, we had to have a root node, even though we'll never use it).
Let's go ahead and take a look at what we have so far. Delete the Default.aspx page that Visual Studio added to your site and replace it with a new Default.aspx page. This time, when you add the page, check the box labeled "Select master page." Then select MasterPage.master as the master page. Build and run the Web application. At this point, you'll see a very simple page that doesn't look like a whole lot (see Figure 2).
The reason our page looks so odd is because we haven't yet defined the Cascading Style Sheet for the page. We need to add the CSS that will actually render what we have as a Tab menu. Add a new style sheet to your project and name it Stylesheet.css. Then, add the following to the <head> of MasterPage.master:
<link href="StyleSheet.css" rel="stylesheet" type="text/css" />
This will link in the new style sheet. Let's take a look at the individual styles that make up our tab control. We'll start with the CSS class named TabMenuContainer. This style is applied to the entire tab menu. We just need to make sure that we have a top border so that our menu has a lid on it.
border-top: solid 1px black;
The next style that we're concerned with is the TabMenuItem. This is the style that is applied to all of our tabs in their unselected state.
border: solid 1px black;
padding: 3px 3px 3px 3px;
Notice that we've defined a border with a single pixel black line. We then set the left border to be nothing. This is actually an intentional move that prevents the tabs from looking bad against the border of the main container.
The secret to this whole method is in the next style. This is the style that is applied to the selected menu item:
border-right: solid 1px black;
padding: 5px 3px 5px 3px;
We set the bottom border to "none" and the background color to white. This will allow the tab to look as if it is attached to the content cell. We also set the top border to "none" to give the selected tab just a little more height than the other tabs.
Since we want our tab panels (the cell that contains the Content-PlaceHolder control) to be the same height from page to page, we should set them to be a specific height. Once again, we use CSS to define a style to do this. In the HTML for the master page we added a table cell to the right of the content container and set its CSS class to SiteContentSpacer. Let's set the style for that to be a specific height.
Not only did we set the height of the content to 200 pixels (a very small number just for demonstration purposes), but we also made the cell invisible. Listing 4 shows the entire style sheet that contains all of the styles used to make our tab control demo.
Once we've added the remaining styles to the style sheet, we can take a look at the final product. Figure 3 shows a screenshot of the resulting page with our tab control and all of the styles defined.
The tab control is a very useful user interface element that is common to many applications. With the introduction of master pages, SiteMapDataSource, and the menu control in ASP.NET 2.0, creating tabs in Web applications is easy. Best of all, once you have the master page set up for tabs, all you have to do to use them is to set the master page on your new Web forms and edit the page as you normally would. Also, since the solution relies on CSS, these tabs work in the latest Web browsers without any client-side coding.
17th Cloud Expo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Meanwhile, 94% of enterprises are using some form of XaaS – software, platform, and infrastructure as a service.
May. 28, 2015 11:15 PM EDT Reads: 2,235
The recent trends like cloud computing, social, mobile and Internet of Things are forcing enterprises to modernize in order to compete in the competitive globalized markets. However, enterprises are approaching newer technologies with a more silo-ed way, gaining only sub optimal benefits. The Modern Enterprise model is presented as a newer way to think of enterprise IT, which takes a more holistic approach to embracing modern technologies.
May. 28, 2015 11:00 PM EDT Reads: 6,040
The true value of the Internet of Things (IoT) lies not just in the data, but through the services that protect the data, perform the analysis and present findings in a usable way. With many IoT elements rooted in traditional IT components, Big Data and IoT isn’t just a play for enterprise. In fact, the IoT presents SMBs with the prospect of launching entirely new activities and exploring innovative areas. CompTIA research identifies several areas where IoT is expected to have the greatest impact.
May. 28, 2015 09:00 PM EDT Reads: 4,956
There's no doubt that the Internet of Things is driving the next wave of innovation. Google has spent billions over the past few months vacuuming up companies that specialize in smart appliances and machine learning. Already, Philips light bulbs, Audi automobiles, and Samsung washers and dryers can communicate with and be controlled from mobile devices. To take advantage of the opportunities the Internet of Things brings to your business, you'll want to start preparing now.
May. 28, 2015 07:00 PM EDT Reads: 5,817
P2P RTC will impact the landscape of communications, shifting from traditional telephony style communications models to OTT (Over-The-Top) cloud assisted & PaaS (Platform as a Service) communication services. The P2P shift will impact many areas of our lives, from mobile communication, human interactive web services, RTC and telephony infrastructure, user federation, security and privacy implications, business costs, and scalability. In his session at @ThingsExpo, Robin Raymond, Chief Architect at Hookflash, will walk through the shifting landscape of traditional telephone and voice services ...
May. 28, 2015 03:00 PM EDT Reads: 4,387
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at Internet of @ThingsExpo, James Kirkland, Chief Architect for the Internet of Things and Intelligent Systems at Red Hat, described how to revolutioniz...
May. 28, 2015 02:00 PM EDT Reads: 4,877
The world is at a tipping point where the technology, the device and global adoption are converging to such a point that we will see an explosion of a world where smartphone devices not only allow us to talk to each other, but allow for communication between everything – serving as a central hub from which we control our world – MediaTek is at the heart of both driving this and allowing the markets to drive this reality forward themselves. The next wave of consumer gadgets is here – smart, connected, and small. If your ambitions are big, so are ours. In his session at @ThingsExpo, Jack Hu, D...
May. 28, 2015 02:00 PM EDT Reads: 701
The security devil is always in the details of the attack: the ones you've endured, the ones you prepare yourself to fend off, and the ones that, you fear, will catch you completely unaware and defenseless. The Internet of Things (IoT) is nothing if not an endless proliferation of details. It's the vision of a world in which continuous Internet connectivity and addressability is embedded into a growing range of human artifacts, into the natural world, and even into our smartphones, appliances, and physical persons. In the IoT vision, every new "thing" - sensor, actuator, data source, data con...
May. 28, 2015 01:00 PM EDT Reads: 6,216
All major researchers estimate there will be tens of billions devices - computers, smartphones, tablets, and sensors - connected to the Internet by 2020. This number will continue to grow at a rapid pace for the next several decades. With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo, June 9-11, 2015, at the Javits Center in New York City. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be
May. 28, 2015 12:15 PM EDT Reads: 2,103
The 4th International Internet of @ThingsExpo, co-located with the 17th International Cloud Expo - to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA - announces that its Call for Papers is open. The Internet of Things (IoT) is the biggest idea since the creation of the Worldwide Web more than 20 years ago.
May. 28, 2015 12:00 PM EDT Reads: 1,725
SYS-CON Events announced today that MetraTech, now part of Ericsson, has been named “Silver Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9–11, 2015, at the Javits Center in New York, NY. Ericsson is the driving force behind the Networked Society- a world leader in communications infrastructure, software and services. Some 40% of the world’s mobile traffic runs through networks Ericsson has supplied, serving more than 2.5 billion subscribers.
May. 28, 2015 12:00 PM EDT Reads: 1,421
SYS-CON Events announced today that O'Reilly Media has been named “Media Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9–11, 2015, at the Javits Center in New York City, NY. O'Reilly Media spreads the knowledge of innovators through its books, online services, magazines, and conferences. Since 1978, O'Reilly Media has been a chronicler and catalyst of cutting-edge development, homing in on the technology trends that really matter and spurring their adoption by amplifying "faint signals" from the alpha geeks who are creating the future. An active participa...
May. 28, 2015 11:30 AM EDT Reads: 699
We’re entering a new era of computing technology that many are calling the Internet of Things (IoT). Machine to machine, machine to infrastructure, machine to environment, the Internet of Everything, the Internet of Intelligent Things, intelligent systems – call it what you want, but it’s happening, and its potential is huge. IoT is comprised of smart machines interacting and communicating with other machines, objects, environments and infrastructures. As a result, huge volumes of data are being generated, and that data is being processed into useful actions that can “command and control” thi...
May. 28, 2015 11:15 AM EDT Reads: 655
There will be 150 billion connected devices by 2020. New digital businesses have already disrupted value chains across every industry. APIs are at the center of the digital business. You need to understand what assets you have that can be exposed digitally, what their digital value chain is, and how to create an effective business model around that value chain to compete in this economy. No enterprise can be complacent and not engage in the digital economy. Learn how to be the disruptor and not the disruptee.
May. 28, 2015 11:08 AM EDT Reads: 565
There's Big Data, then there's really Big Data from the Internet of Things. IoT is evolving to include many data possibilities like new types of event, log and network data. The volumes are enormous, generating tens of billions of logs per day, which raise data challenges. Early IoT deployments are relying heavily on both the cloud and managed service providers to navigate these challenges. In her session at Big Data Expo®, Hannah Smalltree, Director at Treasure Data, discussed how IoT, Big Data and deployments are processing massive data volumes from wearables, utilities and other machines...
May. 28, 2015 10:00 AM EDT Reads: 4,172
Buzzword alert: Microservices and IoT at a DevOps conference? What could possibly go wrong? In this Power Panel at DevOps Summit, moderated by Jason Bloomberg, the leading expert on architecting agility for the enterprise and president of Intellyx, panelists will peel away the buzz and discuss the important architectural principles behind implementing IoT solutions for the enterprise. As remote IoT devices and sensors become increasingly intelligent, they become part of our distributed cloud environment, and we must architect and code accordingly. At the very least, you'll have no problem fil...
May. 28, 2015 10:00 AM EDT Reads: 1,851
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo in Silicon Valley. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal an...
May. 28, 2015 09:00 AM EDT Reads: 2,494
The worldwide cellular network will be the backbone of the future IoT, and the telecom industry is clamoring to get on board as more than just a data pipe. In his session at @ThingsExpo, Evan McGee, CTO of Ring Plus, Inc., discussed what service operators can offer that would benefit IoT entrepreneurs, inventors, and consumers. Evan McGee is the CTO of RingPlus, a leading innovative U.S. MVNO and wireless enabler. His focus is on combining web technologies with traditional telecom to create a new breed of unified communication that is easily accessible to the general consumer. With over a de...
May. 28, 2015 06:00 AM EDT Reads: 4,751
Disruptive macro trends in technology are impacting and dramatically changing the "art of the possible" relative to supply chain management practices through the innovative use of IoT, cloud, machine learning and Big Data to enable connected ecosystems of engagement. Enterprise informatics can now move beyond point solutions that merely monitor the past and implement integrated enterprise fabrics that enable end-to-end supply chain visibility to improve customer service delivery and optimize supplier management. Learn about enterprise architecture strategies for designing connected systems tha...
May. 28, 2015 05:00 AM EDT Reads: 5,924
From telemedicine to smart cars, digital homes and industrial monitoring, the explosive growth of IoT has created exciting new business opportunities for real time calls and messaging. In his session at @ThingsExpo, Ivelin Ivanov, CEO and Co-Founder of Telestax, shared some of the new revenue sources that IoT created for Restcomm – the open source telephony platform from Telestax. Ivelin Ivanov is a technology entrepreneur who founded Mobicents, an Open Source VoIP Platform, to help create, deploy, and manage applications integrating voice, video and data. He is the co-founder of TeleStax, a...
May. 28, 2015 04:00 AM EDT Reads: 6,377