在单击open按钮时，Desktop类将调用系统默认的PDF阅读器，就像在下面的代码中可以看到的那样。

When you click the Open button, the Desktop class invokes the system's default PDF viewer, as you can see in the following code.

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在下面的代码中，请注意该类是如何使用您在PreferencesConstants 类中定义的常量的。

Notice in the following code how the class uses the constants you defined in the PreferencesConstants class.

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在下面的例子中，字符串msg的实例有一个元类，我们可以通过metaClass属性访问该元类。

In the following example, the MSG String instance has got a meta-class that we can access through the metaClass property.

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在下面的例子中，MooTools将会选择CSS类名为 “odd” 的所有表行。

In the following example, MooTools will select every table row with the CSS class "odd," which could be useful for implementing row striping (alternating background colors between table rows)

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在下面的例子中，MooTools将会选择CSS类名为 “odd” 的所有表行。

In the following example, MooTools will select every table row with the CSS class "odd," which could be useful for implementing row striping (alternating background colors between table rows)

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