EMImageMessageBody 成员列表

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

	compressionRatio	EMImageMessageBody
	displayName	EMFileMessageBody
	downloadStatus	EMFileMessageBody
	fileLength	EMFileMessageBody
-	initWithData:displayName:	EMFileMessageBody
-	initWithData:thumbnailData:	EMImageMessageBody
-	initWithLocalPath:displayName:	EMFileMessageBody
	localPath	EMFileMessageBody
	remotePath	EMFileMessageBody
	secretKey	EMFileMessageBody
	size	EMImageMessageBody
	thumbnailDisplayName	EMImageMessageBody
	thumbnailDownloadStatus	EMImageMessageBody
	thumbnailFileLength	EMImageMessageBody
	thumbnailLocalPath	EMImageMessageBody
	thumbnailRemotePath	EMImageMessageBody
	thumbnailSecretKey	EMImageMessageBody
	thumbnailSize	EMImageMessageBody
	type	EMMessageBody