EMFileMessageBody 成员列表

成员的完整列表，这些成员属于 EMFileMessageBody,包括所有继承而来的类成员

	displayName	EMFileMessageBody
	downloadStatus	EMFileMessageBody
	fileLength	EMFileMessageBody
-	initWithData:displayName:	EMFileMessageBody
-	initWithLocalPath:displayName:	EMFileMessageBody
	localPath	EMFileMessageBody
-	NS_UNAVAILABLE (定义于 EMMessageBody)	EMMessageBody
	operationTime	EMMessageBody
	operatorCount	EMMessageBody
	operatorId	EMMessageBody
	remotePath	EMFileMessageBody
	secretKey	EMFileMessageBody
	type	EMMessageBody