环信3.0发图片EMImageMessageBody消息返回Message invalid

环信3.0发图片EMImageMessageBody消息返回错误Message invalid
 
是传入一个image的nsdata类型么?
这种转data可以么?
 
 
//******* 
UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
 NSData *data = UIImagePNGRepresentation(image);
 
//**********
EMImageMessageBody *body = [[EMImageMessageBody alloc] initWithData:mySendMessageModel.imageModel.imageData displayName:@"image.png"];

 NSString *from = [[EMClient sharedClient] currentUsername];

EMMessage *message = [[EMMessage alloc] initWithConversationID:_conversationUserID from:from to:_conversationUserID body:body ext:nil];

message.chatType = EMChatTypeChat;