eclipse 获得透视图切换事件

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<extension point="org.eclipse.ui.startup">   <startup class="de.ralfebert.rcp.tools.preferredperspective.PreferredPerspectivePartListener"/></extension>
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引用地址：http://www.ralfebert.de/blog/eclipsercp/auto_perspective_switch/
http://eclipse.dzone.com/articles/disable-or-enable-actions-sets
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