Simple .NET/ASP.NET PDF document editor web control SDK

Lack of visual cues: Since the entire page doesn t repaint, users may not perceive that anything has changed. Ultimately, this is why FAT was created, but you do have other options. For instance, Gmail uses a Loading icon to indicate that it is doing some work (see Figure 8-5). Depending on your application, you may have to add some sort of indication so your users know what is happening.

Guide chapter on Bluetooth for detailed instructions on establishing links between NXTs. It can be tricky and might require several tries to establish a connection.

how to barcode in excel 2010, barcode generator excel free, barcode for excel 2010, barcode add in for word and excel 11.10 free download, excel barcode generator free download, create barcode macro excel, microsoft excel barcode font, barcode generator macro excel, create barcodes in excel 2010, barcode excel 2007 freeware,

In this chapter, you learned about the imperative features of F#. Combined with the functional features in 3, you now have a full range of techniques to attack any computing problem. F# allows you to choose techniques from the appropriate paradigm and combine them whenever necessary. In the next chapter, you ll see how F# supports the third programming paradigm, object-oriented programming.

The broken back button: Some Web applications deliberately disable the browser s back button, but few Web sites do. Of course, with Ajax, clicking the back button isn t going to do much of anything. If your users are expecting the back button to work, and you re using Ajax to manipulate parts of the page, you may have some problems to solve. Code bloat: Never forget that the JavaScript that powers Ajax applications runs locally on your client. While many developers have powerful machines with reams of random access memory (RAM), some users still have older machines that just don t offer this horsepower. If you put too much JavaScript into your application, you may find sluggish response times on the client side. Even if the JavaScript runs fine, more JavaScript means larger and larger pages, which means longer download times. Until we all have broadband and dualprocessor computers, keep JavaScript to a minimum. Breaking established UI conventions: Ajax lets developers create far richer Web applications than they ve created in the past. However, this doesn t obviate the need to follow normal user interface guidelines. Just because you can do something doesn t mean you should. How will you know if you ve run afoul of any of these gotchas We can t stress this enough: test your design with representative users. Before you role out some snappy new Ajax feature, do some paper mock-ups, and run them by a few users before you spend the time and effort developing it. An hour or two of testing can save you larger issues later.

The NXT is a natural for automating LEGO train control. The variable output power from the NXT is sufficient to operate a train motor, and you can use the Light Sensor or Color Sensor to detect the presence of the train. The power to the tracks uses the same connector as the old RCX (see Figure 14-17). That means you can connect the NXT with the same conversion cable (LEGO #8528) used for the RCX sensors or motor. The prolonged power consumption of operating trains will probably make you wish you had the NXT rechargeable battery pack (LEGO #9798).