C# 5.0 Programmer's Reference

Exercises ❘ 561
3. Write a program similar to the one shown in Figure 24-6 to display the plant data generated
by the program you wrote for Exercise 1 or 2.
Figure 24-6: For Exercise 3, write a
program that displays the plant data
you generated in Exercises 1 and 2.
When it starts, the program should load the plant XML file into a DOM. It should use the
XDocument object’s Descendants method to find Zone elements and use LINQ and to display
a sorted list of the distinct Zone values in the form’s ComboBox.
When the user selects a zone, the program should display the names of the plants in that zone
in the Plants ListBox. (Hints: Use the Descendants method to find Zone elements. Use LINQ
to select the elements with the selected zone. Loop through the selected elements. Use each element’s
Parent property to get to its Plant element. Then use the parent’s Element method to
get the Name subelement.)
When the user clicks a plant in the Plants ListBox, display the information about that
plant. (Hints: Use Descendants again to find Name elements and use LINQ to select the
one with the selected name. Get the first selected element’s parent and call the parent’s
ToString method.)
4. Write a program that reads the plant data generated by the program you wrote for Exercise 1
or 2 and displays a list of the plant records’ names. (Hints: Scan the file to find Name elements.
With those elements, use the reader’s ReadElementContentAsString or ReadInnerXml
method to get the element’s content.)
Compare this program with the one you wrote for Exercise 3. Under what circumstances is
one better than the other
5. Modify the program you wrote for Exercise 3 so that it uses XPath instead of LINQ to find
the elements it needs.
6. Modify the TransformPlanets example program so that it transforms the Plants.xml file created
by the program you wrote for Exercise 1 or Exercise 2 and displays it in an HTML page.
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