Flex4 css中skin设置
header-background-skin:"MySkin";
运行时报错：
TypeError: Error #1034: 强制转换类型失败:无法将 "MySkin" 转换为 Class。 at mx.controls.dataGridClasses::DataGridHeader/updateDisplayList()[E:/dev/hero_private_beta/frameworks/projects/mx/src/mx/controls/dataGridClasses/DataGridHeader.as:331] at mx.core::UIComponent/validateDisplayList()[E:/dev/hero_private_beta/frameworks/projects/framework/src/mx/core/UIComponent.as:8876] at mx.managers::LayoutManager/validateClient()[E:/dev/hero_private_beta/frameworks/projects/framework/src/mx/managers/LayoutManager.as:1010] at mx.core::UIComponent/validateNow()[E:/dev/hero_private_beta/frameworks/projects/framework/src/mx/core/UIComponent.as:7953] at mx.controls.dataGridClasses::DataGridBase/updateDisplayList()[E:/dev/hero_private_beta/frameworks/projects/mx/src/mx/controls/dataGridClasses/DataGridBase.as:594] at mx.controls::DataGrid/updateDisplayList()[E:/dev/hero_private_beta/frameworks/projects/mx/src/mx/controls/DataGrid.as:1741] at mx.controls.listClasses::ListBase/validateDisplayList()[E:/dev/hero_private_beta/frameworks/projects/mx/src/mx/controls/listClasses/ListBase.as:3964] at mx.managers::LayoutManager/validateDisplayList()[E:/dev/hero_private_beta/frameworks/projects/framework/src/mx/managers/LayoutManager.as:719] at mx.managers::LayoutManager/doPhasedInstantiation()[E:/dev/hero_private_beta/frameworks/projects/framework/src/mx/managers/LayoutManager.as:778] at mx.managers::LayoutManager/doPhasedInstantiationCallback()[E:/dev/hero_private_beta/frameworks/projects/framework/src/mx/managers/LayoutManager.as:1157]
解决办法：
header-background-skin:ClassReference("MySkin");
原理：
强行转换
