ScrollPolicy

Flex: verticalScrollPolicy auto/on/off

Categories: Flex; Tagged with: ActionScript • Flex • ScrollPolicy; @ December 5th, 2011 23:54

最近碰到一个问题: 当Flex右侧垂直滚动条出现时, 下方水平滚动条必定随之出现, 详细的描述就是:

该UIComponent高度一定, 宽度设置为percent(也就是说宽度可以变化), 当Add一个内部组件到该UI上后, UI需要更多高度, 但高度一定, 只好出现右侧滚动条(默认的ScrollPolicy为auto), 假使被增加组件的宽度与外部组件宽度一致, 此时由于滚动条的出现, 外部UI不能直接完整显示该组件, 于是出现水平滚动条,.

Flex API中有关内容: Sizing components http://livedocs.adobe.com/flex/3/html/help.html?content=size_position_3.html

参考: Using Scroll bars一章:

Notice that the addition of the scroll bar doesn’t increase the height of the container from its initial value. Flex considers scroll bars in its sizing calculations only if you explicitly set the scroll policy to

ScrollPolicy.ON. So, if you use an auto scroll policy (the default), the scroll bar overlaps the buttons. To prevent this behavior, you can set the

heightproperty for the HBox container or allow the HBox container to resize by setting a percentage-based width. Remember that changing the height of the HBox container causes other components in your application to move and resize according to their own sizing rules.

解决方案比较清晰, 要么设置ScrollPoliocy为No, 要么调整宽高设置. 为了清晰演示, 写了个小Application:

Flex3TestWeb_ScrollPolicy