sd卡的监听

安装SD卡： action=android.intent.action.MEDIA_CHECKING

　　　　　　action = android.intent.action.MEDIA_MOUNTED

卸载SD卡：android.intent.action.MEDIA_UNMOUNTED

未卸载直接拔出SD卡：action=android.intent.action.MEDIA_BAD_REMOVAL

卸载后拔出SD卡：action=android.intent.action.MEDIA_REMOVED

卸载或直接拔出SD卡：action=android.intent.action.MEDIA_EJECT